31;IfcOrganization;"<EPM-HTML>
<p>A named and structured grouping with a corporate identity.</p>

<blockquote class=""note"">
NOTE: The relationships between <I>IfcOrganizations</I>, like a Department within a Company, can be expressed using <I>IfcOrganizationRelationship</I>.
</blockquote>

<blockquote class=""note"">
NOTE Corresponds to the following entity in ISO-10303-41: organization.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.<br>
IFC 2x4 change: attribute <I>Id</I> renamed to <i>Identification</i>.
</blockquote>

</EPM-HTML>"
40;IfcActorRole;"<EPM-HTML>

<p>Definition: A role which is performed by an actor, either a person, an organization or a 
person related to an organization.</p>

<blockquote class=""note"">
NOTE: The list of roles of the enumeration values of the <I>Role</I> attribute can never
be complete. Therefore using enumeration value USERDEFINED, the user can provide his/her own role as a value 
of the attribute <I>UserDefinedRole</I>.
</blockquote>

<blockquote class=""note"">
  Corresponds to the following entity in ISO-10303-41: organization_role and person_role.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1
</blockquote>

</EPM-HTML>"
70;IfcAddress;"<EPM-HTML>

<p>Definition: An abstract entity type for various kinds of postal and telecom addresses.</p>

<blockquote class=""note"">
NOTE Corresponds to the following entity in ISO-10303-41: address.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
79;IfcPostalAddress;"<EPM-HTML>
<p>Definition: The address for delivery of paper based mail.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
88;IfcTelecomAddress;"<EPM-HTML>
<p>Definition: Address to which telephone, electronic mail and other forms of telecommunications should be addressed.</p>

<blockquote>
HISTORY New entity in IFC Release 2x.
<br>
IFC 2x4 change:  Added attribute <i>MessagingIDs</i>.
Type of attribute <i>WWWHomePageURL</i> compatibly changed from <i>IfcLabel</i> to <i>IfcURIReference</i>.
</blockquote>

</EPM-HTML>"
102;IfcPerson;"<EPM-HTML>
<p>Definition: an individual human being.</p>

<blockquote class=""note"">
NOTE Many countries have legislation concerning the identification of individual persons within databases. Although the intent of the IFC Model is to act as a specification for data exchange 
and sharing, an IFC file might in some situations be considered to be a database that enables identification of a particular person under the terms of such legislation. Users should be aware of the constraints of legislation that might apply in the places where IFC files are used.
</blockquote>

<blockquote class=""note"">
NOTE Corresponds to the following entity in ISO-10303-41: person.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.<br>
IFC 2x4 change: attribute <I>Id</I> renamed to <I>Identification</I>.  WHERE rule relaxed to allow omission of names if <i>Identification</i> is provided.
</blockquote>

</EPM-HTML>"
113;IfcPersonAndOrganization;"<EPM-HTML>

<p>Definition: Identification of a person within an organization.</p>

<blockquote class=""note"">
NOTE Corresponds to the following entity in ISO-10303-41: person_and_organization.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1
</blockquote>

</EPM-HTML>"
117;IfcOrganizationRelationship;"<EPM-HTML>
<p>Definition: establishes an association between one relating organization and one or more related organizations.</p>

<blockquote class=""note"">
NOTE Corresponds to the following entity in ISO-10303-41: organization_relationship.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.<BR>
IFC 2x4 change: attribute <I>Name</I> made optional.
</blockquote>

</EPM-HTML>"
123;IfcApproval;"<EPM-HTML>

<p>Definition: An <i>IfcApproval</i> represents information about approval processes such as for a plan, a design, a proposal, or a change order in a construction or facilities management project. <i>IfcApproval</i> is referenced by <i>IfcRelAssociatesApproval</i> in <i>IfcControlExtension</i> schema, and thereby can be related to all subtypes of <i>IfcRoot</i>. An approval may also be given to resource objects using <i>IfcResourceApprovalRelationship</i>
</p>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2.0
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x Edition 4 CHANGE&nbsp; Attributes Identifier and Name made optional, where rule added to require at least one of them being asserted. Inverse attributes ApprovedObjects, ApprovedResources and HasExternalReferences added. Inverse attribute Properties deleted (more general relationship via inverse ApprovedResources to be used instead).
</blockquote>

</EPM-HTML>"
139;IfcApprovalRelationship;"<EPM-HTML> 

<p>An <i>IfcApprovalRelationship</i> associates approvals (one
relating approval and one or more related approvals), each having different status or level as the approval process or the approved
objects evolve.</p>

<blockquote class=""history"">
HISTORY: New entity in Release IFC2x2.</span><br>
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Subtyped from <em>IfcResourceLevelRelationship</em>, order of attributes changed.
</blockquote>

</EPM-HTML>"
142;IfcResourceApprovalRelationship;"<EPM-HTML>
<p>An <i>IfcResourceApprovalRelationship</i> is used for
associating an approval to resource objects. A single approval
might be given to one or many items via <i>IfcResourceObjectSelect</i>.</p>

<blockquote class=""history"">
HISTORY&nbsp; New
Entity in IFC Release 2x4
</blockquote>

</EPM-HTML>"
146;IfcPerformanceHistory;"<EPM-HTML>

<p><i>IfcPerformanceHistory</i> is used to document the actual performance of an occurrence instance over time. In practice, performance-related data are generally not easy to obtain as they can originate from different sources (predicted, simulated, or measured) and occur during different stages of the building life-cycle. Such time-related data cover a large spectrum, including meteorological data, schedules, operational status measurements, trend reports, etc.</p>

<p><i>IfcPerformanceHistory</i> is assigned to other objects (represented by subtypes of <i>IfcObjectDefinition</i>, excluding subtypes of <i>IfcControl</i>), by the objectified relationship <i>IfcRelAssignsToControl</i>.
</p>

<blockquote class=""history"">
HISTORY: New entity in Release IFC2x Edition 2.
</blockquote> 

</EPM-HTML>"
152;IfcRelAssociatesApproval;"<EPM-HTML>

<p>The entity <i>IfcRelAssociatesApproval</i> is used to apply approval information defined by <i>IfcApproval</i>, in <i>IfcApprovalResource</i> schema, to subtypes of <i>IfcRoot</i>.
</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote> 

</EPM-HTML>"
154;IfcRelAssociatesConstraint;"<EPM-HTML>

<p>The entity <i>IfcRelAssociatesConstraint</i> is used to apply constraint information defined by <i>IfcConstraint</i>, in the <i>IfcConstraintResource</i> schema, to subtypes of <i>IfcRoot</i>.
</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote> 

</EPM-HTML>"
157;IfcRelAssociatesTimeSeries;"<EPM-HTML>

<p><i>IfcRelAssociatesTimeSeries</i> associates to objects (subtypes of <i>IfcRoot</i>) a time-series that is applicable to one or more calendar dates.</p>

<blockquote class=""history"">
HISTORY: New entity in Release IFC2x Edition 2.
</blockquote> 

<blockquote class=""change-ifc2x4"">
IFC2x Edition 4 CHANGE entity renamed to <i>IfcRelAssociatesTimeSeries</i> and made an objectified realtionship (subtype of <i>IfcRelAssociates</i>), replacing the old entity <i>IfcTimeSeriesSchedule</i> (was subtype of <i>IfcControl</i>
</blockquote>

</EPM-HTML>"
162;IfcPileType;"<EPM-HTML>

<p><u>Definition from IAI:</u> Provides shared material, decomposition, representation maps, and property sets for instances of <i>IfcPile</i>.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x4</font></blockquote>

<p><u><b>Material Use Definition</b></u>:</p>

<p>Material profile set association analogous to <a href=""../../ifcsharedbldgelements/lexical/ifccolumnstandardcase.htm""><i>IfcColumnStandardCase</i></a> should be used when applicable.</p>

</EPM-HTML>"
174;IfcFootingType;"<EPM-HTML>

<p><u>Definition from IAI:</u> Provides shared material, decomposition, representation maps, and property sets for instances of <i>IfcFooting</i>.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x4</font></blockquote>

<p>Note, slab foundation types are not instantiated as <i>IfcFootingType</i> but as <i>IfcSlabType</i> with a predefined type of <i>IfcSlabTypeEnum</i>.BASESLAB.</p>

<p><u><b>Material Use Definition</b></u>:</p>

<p>Material profile set or material layer set association analogous to <a href=""../../ifcsharedbldgelements/lexical/ifcbeamstandardcase.htm""><i>IfcBeamStandardCase</i></a> or <a href=""../../ifcsharedbldgelements/lexical/ifcslabstandardcase.htm""><i>IfcSlabStandardCase</i></a> should be used when applicable.</p>

</EPM-HTML>"
185;IfcSurfaceFeature;"<EPM-HTML>

<p><u>Definition from IAI:</u> A surface feature is a modification at (onto, or into) of the surface of an element.  Parts of the surface of the entire surface may be affected.  The volume and mass of the element may be increased, remain unchanged, or be decreased by the surface feature, depending on manufacturing technology.</u></p>

<p>The standard use of instances of <i>IfcSurfaceFeature</i> is as a part of element type objects (instances of subtypes of <i>IfcElementType</i>).  The part&ndash;whole relationship is established by an aggregation relationship object, expressing the decomposition of an element type into one or more additive elements (element parts) and zero or more feature elements.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New type in IFC 2x4.</font></blockquote>

<p><b><u>Containment Use Definition</u></b>:</p>

<p>Surface features shall have no spatial containment relationship to the spatial structure since they are dependent on element types without spatial containment relationships or on an element occurrence with own spatial containment relationship.</p>
<ul>
  <li>The <i>SELF\IfcElement.ContainedInStructure</i> relationship shall be NIL.</li>
</ul>

<p><b><u>Geometry use definition</u></b>:</p>

<p>The geometric representation of <i>IfcSurfaceFeatureElement</i> is given by the <i>IfcProductDefinitionShape</i>, allowing multiple geometric representation.</p>

<p><b>Local Placement</b></p>

<p>The local placement for <i>IfcSurfaceFeatureElement</i> is defined in its supertype <i>IfcProduct</i>. It is defined by the <i>IfcLocalPlacement</i>, which defines the local coordinate system that is referenced by all geometric representations.</p>
<ul>
  <li>In case of features which are part of an element type, absolute placement into the type object's implied coordinate system shall be used.</li>
  <li>In case of features which are voiding an element occurrence, the <i>PlacementRelTo</i> relationship of <i>IfcLocalPlacement</i> shall point to the local placement of the respective element.</li>
</ul>

<p><b>Shape representation</b></p>

<p>Different shape representations may be used, depending on the nature of the feature and information requirements:</p>
<ul>
  <li>Symbolic representation, such as the two-dimensional bounding box of a tag.</p>
  <li>A geometric set representing the geometric items of a mark.</li>
  <li>Surface representations of treated parts of the lement surface by means of <i>IfcShellBasedSurfaceModel</i>.  The faces within the surface model may be included into a B-Rep model within a representation map of the parent element type.</li>
</ul>

<p>Higher-level parameters (geometric and non-geometric) may be provided by property sets based on local agreements.</p>

</EPM-HTML>
"
194;IfcVoidingFeature;"<EPM-HTML>

<p><u>Definition from IAI:</u> A voiding feature is a modification of an element which reduces its volume.  Such a feature may be manufactured in different ways, for example by cutting, drilling, or milling of members made of various materials, or by inlays into the formwork of cast members made of materials such as concrete.</u></p>

<p>The standard use of instances of <i>IfcVoidingFeature</i> is as a part of element type objects (instances of subtypes of <i>IfcElementType</i>).  The part&ndash;whole relationship is established by an aggregation relationship object, expressing the decomposition of an element type into one or more additive elements (element parts) and zero or more feature elements.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New type in IFC 2x4.</font></blockquote>

<p><b><u>Containment Use Definition</u></b>:</p>

<p>Voiding features shall have no spatial containment relationship to the spatial structure since they are dependent on element types without spatial containment relationships or on an element occurrence with own spatial containment relationship.</p>
<ul>
  <li>The <i>SELF\IfcElement.ContainedInStructure</i> relationship shall be NIL.</li>
</ul>

<p><b><u>Geometry use definition</u></b>:</p>

<p>The geometric representation of <i>IfcVoidingFeatureElement</i> is given by the <i>IfcProductDefinitionShape</i>, allowing multiple geometric representation.</p>

<p><b>Local Placement</b></p>

<p>The local placement for <i>IfcVoidingFeatureElement</i> is defined in its supertype <i>IfcProduct</i>. It is defined by the <i>IfcLocalPlacement</i>, which defines the local coordinate system that is referenced by all geometric representations.</p>
<ul>
  <li>In case of features which are part of an element type, absolute placement into the type object's implied coordinate system shall be used.</li>
  <li>In case of features which are voiding an element occurrence, the <i>PlacementRelTo</i> relationship of <i>IfcLocalPlacement</i> shall point to the local placement of the respective element.</li>
</ul>

<p><b>Shape representation</b></p>

<p>Different shape representations may be used, depending on the nature of the feature and information requirements:</p>
<ul>
  <li>Symbolic representations, such as an axis representation, may be used for simple shapes such as holes or edge features.</p>
  <li>Volumetric representations by means of subtypes of <i>IfcSweptSurface</i> or of <i>IfcCsgPrimitive3D</i> may be used to semi-parametrically model the actual volume of the void created by the feature.  The objects within the shape model of the feature's shape representation can be included into a CSG model within a representation map of the parent element type.</li>
  <li>Surface representations of cutting planes by means of <i>IfcShellBasedSurfaceModel</i>.  The faces within the surface model may be included into a B-Rep model within a representation map of the parent element type.</li>
</ul>

<p>Higher-level parameters (geometric and non-geometric) may be provided by property sets based on local agreements.</p>

</EPM-HTML>
"
206;IfcFooting;"<EPM-HTML>

<p>A footing is a part of the foundation of a structure that spreads and transmits the load to the soil, either directly or via piles.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x2
</blockquote>

<p>Note, slab foundations are not instantiated as <i>IfcFooting</i> but as <i>IfcSlab</i> or <i>IfcSlabStandardCase</i> with a predefined type of <i>IfcSlabTypeEnum</i>.BASESLAB.</p>

<p class=""use-head"">Property Set Use Definition</p>

<p>The following property set definitions are part of this IFC release:</p>

<ul>
  <li><a href=""../../psd/IfcStructuralElementsDomain/Pset_FootingCommon.xml"" target=""SOURCE"">Pset_FootingCommon</a>: common property set for all footing occurrences.</li>
  <li><a href=""../../psd/IfcStructuralElementsDomain/Pset_ReinforcementBarCountOfIndependentFooting.xml"" target=""SOURCE"">Pset_ReinforcementBarCountOfIndependentFooting</a>: property set for independent <i>IfcFooting</i> occurrences.</li>
  <li><a href=""../../psd/IfcStructuralElementsDomain/Pset_ReinforcementBarPitchOfContinuousFooting.xml"" target=""SOURCE"">Pset_ReinforcementBarPitchOfContinuousFooting</a>: property set for continuous <i>IfcFooting</i> occurrences.</li>
</ul>

<p class=""use-head"">Quantity Use Definition</p> 
<p> The quantities relating to this entity are defined by <a href=""../../ifcproductextension/lexical/ifcelementquantity.htm"">IfcElementQuantity</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities, being subjected to local standard of measurement, can be defined with another string value assigned to <i>Name</i>. In this case a valid value for <i>MethodOfMeasurement</i> has to be provided. </p> 
<ul> 
<li><a href=""../../qto/IfcStructuralElementsDomain/Qto_FootingBaseQuantities.xml"" target=""SOURCE"">Qto_FootingBaseQuantities</a></li> 
</ul>  

<p class=""use-head"">Geometry Use Definition</p>

<p>Local placement and product representations are defined by the supertype <a href=""../../ifcproductextension/lexical/ifcbuildingelement.htm""><i>IfcBuildingElement</i></a>.  Standard representations as defined at <a href=""../../ifcsharedbldgelements/lexical/ifcbeamstandardcase.htm""><i>IfcBeamStandardCase</i></a> or <a href=""../../ifcsharedbldgelements/lexical/ifcslabstandardcase.htm""><i>IfcSlabStandardCase</i></a> should be used when applicable.</p>

</EPM-HTML>"
210;IfcPile;"<EPM-HTML>

<p>A pile is a slender timber, concrete, or steel structural element, driven, jetted, or otherwise embedded on end in the ground for the purpose of supporting a load.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x2
</blockquote>

<p class=""use-head"">Property Set Use Definition</p>

<p>The following property set definitions are part of this IFC release:</p>

<ul>
  <li><a href=""../../psd/IfcStructuralElementsDomain/Pset_PileCommon.xml"" target=""SOURCE"">Pset_PileCommon</a>: common property set for all pile occurrences.</li>
</ul>

<p class=""use-head"">Quantity Use Definition</p> 
<p> The quantities relating to this entity are defined by <a href=""../../ifcproductextension/lexical/ifcelementquantity.htm"">IfcElementQuantity</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities, being subjected to local standard of measurement, can be defined with another string value assigned to <i>Name</i>. In this case a valid value for <i>MethodOfMeasurement</i> has to be provided. </p> 
<ul> 
<li><a href=""../../qto/IfcStructuralElementsDomain/Qto_PileBaseQuantities.xml"" target=""SOURCE"">Qto_PileBaseQuantities</a></li> 
</ul>  

<p class=""use-head"">Geometry Use Definition</p>

<p>Local placement and product representations are defined by the supertype <a href=""../../ifcproductextension/lexical/ifcbuildingelement.htm""><i>IfcBuildingElement</i></a>.  Standard representations as defined at <a href=""../../ifcsharedbldgelements/lexical/ifccolumnstandardcase.htm""><i>IfcColumnStandardCase</i></a> should be used when applicable.</p>

</EPM-HTML>"
222;IfcReinforcingElementType;"<EPM-HTML>

<p><u>Definition from IAI:</u> Types of bars, wires, strands, meshes, tendons, and other components embedded in concrete in such a manner that the reinforcement and the concrete act together in resisting forces.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x4</font></blockquote>

</EPM-HTML>
"
230;IfcReinforcingElement;"<EPM-HTML>

<p><u>Definition from IAI:</u> Bars, wires, strands, meshes, tendons, and other components embedded in concrete in such a manner that the reinforcement and the concrete act together in resisting forces.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x2</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 CHANGE Entity made non-abstract.<br>
Subtypes <i>IfcTendon</i> and <i>IfcTendonAnchor</i> removed.<br>
Attribute <i>SteelGrade</i> removed.<br>
Attributes <i>PredefinedType</i> and <i>Role</i> added.</font></blockquote>

</EPM-HTML>
"
237;IfcReinforcingBar;"<EPM-HTML>

<p><u>Definition from IAI:</u> A steel bar, usually with manufactured deformations in the surface,
used in concrete and masonry construction to provide additional strength.  A single instance
of this class may represent one or many of actual rebars, for example a row of rebars.</p></p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x2</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 CHANGE All attributes removed; information now provided by <i>IfcReinforcingBarType</i>.</font></blockquote>

<p><u><b>Geometry Use Definition</b></u></p>

<p> The geometric representation of <i>IfcReinforcingBar</i> is given by the <i>IfcProductDefinitionShape</i>,
allowing multiple geometric representations. Included are:</p>

<p><b>Local Placement</b><br>
The use of local placement is defined at the supertype <i>IfcElementComponent</i>.</p>

<p><b>Multiple Mapped Representation</b><br>
See supertype <i>IfcElementComponent</i>.  This method of representation allows for several rebars
represented by a single instance of <i>IfcReinforcingBar</i>.  The representation map should contain
one <i>IfcSweptDiskSolidPolygonal</i>.</p>

<p>An <i>IfcElementQuantity</i>,
attached via <i>IfcRelDefinesByProperties</i>, should contain an <i>IfcQuantityCount</i> named 'Count'
with the number rebars and, if this is a regularly spaced arrangement of rebars, an
<i>IfcQuantityLength</i> named 'Spacing' which expresses the center-to-center distances of bars.</p>

<p><b>Simplified Geometric Representation</b><br>
Simplified geometric representations may be used based on local agreements.</p>


</EPM-HTML>
"
249;IfcReinforcingMesh;"<EPM-HTML>

<p><u>Definition from IAI:</u> A series of longitudinal and transverse wires or bars of various gauges, arranged at right angles to each other and welded at all points of intersection; usually used for concrete slab reinforcement. Also known as welded wire fabric.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x2</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 CHANGE All attributes removed; information now provided by <i>IfcReinforcingMeshType</i>.</font></blockquote>

<p><u><b>Geometry Use Definition</b></u></p>

<p> The geometric representation of <i>IfcReinforcingBar</i> is given by the <i>IfcProductDefinitionShape</i>,
allowing multiple geometric representations. Included are:</p>

<p><b>Local Placement</b><br>
The use of local placement is defined at the supertype <i>IfcElementComponent</i>.</p>

<p><b>Multiple Mapped Representation</b><br>
See supertype <i>IfcElementComponent</i>.  This method of representation allows for several meshes
represented by a single instance of <i>IfcReinforcingMesh</i>.</p>

<p>An <i>IfcElementQuantity</i>,
attached via <i>IfcRelDefinesByProperties</i>, should contain an <i>IfcQuantityCount</i> named 'Count'
with the number of meshes represented by this instance.</p>

<p><b>Simplified Geometric Representation</b><br>
Simplified geometric representations may be used based on local agreements.</p>


</EPM-HTML>
"
252;IfcReinforcingBarType;"<EPM-HTML>

<p><u>Definition from IAI:</u> A steel bar, usually with manufactured deformations in the surface,
used in concrete and masonry construction to provide additional strength.</p></p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x4</font></blockquote>

<p><u><b>Material Use Definition</b></u>:</p>

<p>An associated material denotes the steel grade, preferrably by material classification.</p>

<p><u><b>Geometry Use Definition</b></u>:</p>

<p>The <i>IfcReinforcingBarType</i> may define the shared geometric representation for all rebar occurrences. The <i>RepresentationMaps</i> attribute refers to a list of <i>IfcRepresentationMap</i>'s, that allow for multiple geometric representations (e.g. with <i>IfcShapeRepresentation</i>'s having an <i>RepresentationIdentifier</i> 'Box', 'Axis', or 'Body').</p>

<p>A 'Body' representation map should contain one <i>IfcSweptDiskSolidPolygonal</i>.</p>

<p>Simplified geometric representations may be used based on local agreements.</p>


</EPM-HTML>
"
258;IfcReinforcingMeshType;"<EPM-HTML>

<p><u>Definition from IAI:</u> A series of longitudinal and transverse wires or bars of various gauges, arranged at right angles to each other and welded at all points of intersection; usually used for concrete slab reinforcement. Also known as welded wire fabric.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x4</font></blockquote>

<p><u><b>Material Use Definition</b></u>:</p>

<p>An associated material denotes the steel grade, preferrably via material classification.</p>

<p><u><b>Geometry Use Definition</b></u>:</p>

<p>The <i>IfcReinforcingMeshType</i> may define the shared geometric representation for all mesh occurrences. The <i>RepresentationMaps</i> attribute refers to a list of <i>IfcRepresentationMap</i>'s, that allow for multiple geometric representations.</p>


</EPM-HTML>
"
271;IfcReinforcementDefinitionProperties;"<EPM-HTML>
	 <P> <U>Definition from IAI:</U> An
		<I>IfcReinforcementDefinitionProperties</I> defines the cross section
		properties of reinforcement included in reinforced concrete building elements.
		The property set definition may be used both in conjunction with insitu and
		precast structures. </P> 

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x2<br>
IFC 2x4 change: Supertype changed from <i>IfcPropertySetDefinition</i> to <i>IfcPreDefinedPropertySet</i></font></blockquote>

	 <P><B>General usage:</B></P> 
	 <P> This subtype of <I>IfcPropertySetDefinition</I> is used to define the
		reinforcement properties in early design stages, such as in requirement
		definition or scheme design. In later design stages explicit instances of
		subtypes of <I>IfcReinforcingElement</I> are used. The intended usage may be
		indicated using the <I>DefinitionType</I> attribute value as a designator:
		recommended values are 'Reinforcement area requirement' or 'Reinforcement
		configuration requirement'. Other values may be used according to local
		standards. </P> 
	 <P> Only one property set definition of this kind is used for each concrete
		building element in each intended usage indicated by the <I>DefinitionType</I>
		attribute value. This set then defines a list of cross section properties in a
		discrete number of longitudinal sections as instances of
		<I>IfcSectionReinforcementProperties</I> (one for each structural reinforcement
		bar role), which in turn have a section cross section property defined as a
		profile and a number of reinforcement properties, one for each steel grade /
		bar type. </P>
</EPM-HTML>"
279;IfcPreDefinedTextFont;"<EPM-HTML>

<p>The pre defined text font determines those qualified names which can be used for fonts that are in scope of the current data exchange specification (in contrary to externally defined text fonts). There are two choices:</p>
<ul>
  <li><i>IfcDraughtingPreDefinedTextFont</i> for definitions from ISO/IS 10303-46:1994 for (old) vector based and monospace text.<br>
  </li>
  <li><i>IfcTextStyleFontModel</i> for definitions from <a target=""_blank"" href=""http://www.w3.org/TR/REC-CSS1"">Cascading Style Sheets, level 1</a>, W3C Recommendation 17 Dec 1996, revised 11 Jan 1999, CSS1, for all true type text. The use of the CSS1 definitions is the preferred way to represent text fonts.</li>
</ul>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: pre_defined_text_font. Please refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The <i>IfcTextStyleFontModel</i> has been added as new subtype.
</blockquote>

</EPM-HTML>"
282;IfcPreDefinedItem;"<EPM-HTML>

<p>A pre defined item is a qualified name given to a style or font which is determined within the data exchange specification by convention on using the <i>Name</i> attribute value (in contrary to externally defined items, which are agreed by an external source).</p>

<blockquote class=""note"">
NOTE&nbsp; The convention on using the <i>Name</i> value is defined at the subtypes of <i>IfcPreDefinedItem</i> and is part of the specification.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: pre_defined_item. Please refer to ISO/IS 10303-41:1994, page 137 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
286;IfcPreDefinedColour;"<EPM-HTML>

<p>The pre defined colour determines those qualified names which can be used to identify a colour that is in scope of the current data exchange specification (in contrary to colour specification which defines the colour directly by its colour components).</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: pre_defined_colour. It has been made into an abstract entity in IFC. Please refer to ISO/IS 10303-46:1994, p. 141 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
288;IfcDraughtingPreDefinedColour;"<EPM-HTML>

<p>The draughting pre defined colour is a pre defined colour for the purpose to identify a colour by name. Allowable names are:</p>
<ul>
<li>'black',</li>
<li>'red',</li>
<li>'green',</li>
<li>'blue',</li>
<li>'yellow',</li>
<li>'magenta',</li>
<li>'cyan',</li>
<li>'white',</li>
<li>'by layer'</li>
</ul>

<blockquote class=""note"">
NOTE&nbsp;˙The <i>IfcDraughtingPreDefinedColour</i> is an entity that had been adopted from ISO 10303-202, Industrial automation systems and integration&mdash;Product data representation and exchange, Part 202: Application protocol: Associative draughting.
</blockquote>

<p>The following table states the RGB values associated with the names given by the <i>IfcDraughtingPreDefinedColour.</i></p>
<blockquote>
<table>
<tbody>
<tr>
<td><b>Colour name</b></td>
<td align=""center""><b>Red</b></td>
<td align=""center""><b>Green</b></td>
<td align=""center""><b>Blue</b></td>
</tr>
<tr>
<td>black</td>
<td align=""center"">0</td>
<td align=""center"">0</td>
<td align=""center"">0</td>
</tr>
<tr>
<td>red</td>
<td align=""center"">1.0</td>
<td align=""center"">0</td>
<td align=""center"">0</td>
</tr>
<tr>
<td>green</td>
<td align=""center"">0</td>
<td align=""center"">1.0</td>
<td align=""center"">0</td>
</tr>
<tr>
<td>blue</td>
<td align=""center"">0</td>
<td align=""center"">0</td>
<td align=""center"">1.0</td>
</tr>
<tr>
<td>yellow</td>
<td align=""center"">1.0</td>
<td align=""center"">1.0</td>
<td align=""center"">0</td>
</tr>
<tr>
<td>magenta</td>
<td align=""center"">1.0</td>
<td align=""center"">0</td>
<td align=""center"">1.0</td>
</tr>
<tr>
<td>cyan</td>
<td align=""center"">0</td>
<td align=""center"">1.0</td>
<td align=""center"">1.0</td>
</tr>
<tr>
<td>white</td>
<td align=""center"">1.0</td>
<td align=""center"">1.0</td>
<td align=""center"">1.0</td>
</tr>
<tr valign=""top"">
<td>by layer</td>
<td align=""left"" colspan=""3"">colour values obtained from<br>
<i>IfcPresentationLayerWithStyle</i>.</td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
</blockquote>

<blockquote class=""note"">
NOTE&nbsp;˙Corresponding ISO 10303 name: draughting_pre_defined_colour. Please refer to ISO/IS 10303-202:1994 page 194 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp;˙New entity in IFC2x2.
</blockquote>

<p><u>Informal proposition</u></p>
<ol>
<li>The value 'by layer' shall only be inserted, if the geometric representation item using the colour definition has an association to <i>IfcPresentationLayerWithStyle</i>, and if that instance of <i>IfcPresentationLayerWithStyle</i> has a valid colour definition for <i>IfcCurveStyle</i>, <i>IfcSymbolStyle</i>, or <i>IfcSurfaceStyle</i> (depending on what is applicable).</li>
</ol>

</EPM-HTML>"
290;IfcDraughtingPreDefinedTextFont;"<EPM-HTML>

<p>The draughting pre defined text font is a pre defined text font for the purpose to identify a font by name. Allowable names are:</p>
<ul>
  <li>'ISO 3098-1 font A',</li>
  <li>'ISO 3098-1 font B',</li>
</ul>
<p>The ISO 3098-1 font A is the text font as denoted as Letterng A in clause 3 of ISO 3098-1, the ISO 3098-1 font B is the text font as denoted as Letterng B in clause 3 of ISO 3098-1.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcDraughtingPreDefinedTextFont</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&mdash;Product data representation and exchange, Part 202: Application protocol: Associative draughting. Corresponding ISO 10303 name: draughting_pre_defined_text_font. Please refer to ISO/IS 10303-202:1994 page 196 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
292;IfcTextStyleFontModel;"<EPM-HTML>

<p><u>Definition from CSS1 (W3C Recommendation)</u>: Setting font properties will be among the most common uses of style sheets. Unfortunately, there exists no well-defined and universally accepted taxonomy for classifying fonts, and terms that apply to one font family may not be appropriate for others. For example, 'italic' is commonly used to label slanted text, but slanted text may also be labeled as being <i>Oblique</i>, <i>Slanted</i>, <i>Incline</i>, <i>Cursive</i> or <i>Kursiv</i>. Therefore it is not a simple problem to map typical font selection properties to a specific font.</p>

<p><b>Font matching</b></p>
<p>Because there is no accepted, universal taxonomy of font properties, matching of properties to font faces must be done carefully. The properties are matched in a well-defined order to ensure that the results of this matching process are as consistent as possible across user agents (assuming that the same library of font faces is presented to each of them).
</p>

<ol>
  <li>The user agent makes (or
accesses) a database of relevant CSS1
properties of all the fonts of which the UA is aware. The UA may be
aware of a font because it has been installed locally or it has been
previously downloaded over the web. If there are two fonts with
exactly the same properties, one of them is ignored. </li>
  <li>At a given element and for
each character in that element, the UA
assembles the font-properties applicable to that element. Using the
complete set of properties, the UA uses the 'font-family' property to
choose a tentative font family. The remaining properties are tested
against the family according to the matching criteria described with
each property. If there are matches for all the remaining properties,
then that is the matching font face for the given element. </li>
  <li>If there is no matching font
face within the 'font-family' being
processed by step 2, and if there is a next alternative 'font-family'
in the font set, then repeat step 2 with the next alternative
'font-family'. </li>
  <li>If there is a matching font
face, but it doesn't contain a glyph
for the current character, and if there is a next alternative
'font-family' in the font sets, then repeat step 2 with the next
alternative 'font-family'.&nbsp; </li>
  <li>If there is no font within
the family selected in 2, then use a
UA-dependent default 'font-family' and repeat step 2, using the best
match that can be obtained within the default font. </li>
</ol>
<p>(The above algorithm can be
optimized to avoid having to revisit
the CSS1 properties for each character.)
</p>
<p>The per-property matching rules
from (2) above are as follows:
</p>
<ol>
  <li>'font-style' is tried first.
'italic'
will be satisfied if there is either a face in the UA's font database
labeled with the CSS keyword 'italic' (preferred) or 'oblique'.
Otherwise the values must be matched exactly or font-style will fail. </li>
  <li>'font-variant' is tried
next. 'normal'
matches a font not labeled as 'small-caps'; 'small-caps' matches (1) a
font labeled as 'small-caps', (2) a font in which the small caps are
synthesized, or (3) a font where all lowercase letters are replaced by
upper case letters. A small-caps font may be synthesized by
electronically scaling uppercase letters from a normal font. </li>
  <li>'font-weight' is matched next, it will never fail. (See 'font-weight' below.) </li>
  <li>'font-size' must be matched within a
UA-dependent margin of tolerance. (Typically, sizes for scalable fonts
are rounded to the nearest whole pixel, while the tolerance for
bitmapped fonts could be as large as 20%.) Further computations, are
based on the 'font-size' value that is used, not the one that is specified.</li>
</ol>

<p>The inherited <i>Name</i> attribute is used to define the font name, particularly in cases, where no (list of) font families are provided. </p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding CSS1 definitions are Font properties ('font-family', 'font-style', 'font-variant',&nbsp; 'font-weight').</font>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

</EPM-HTML>"
306;IfcExternallyDefinedTextFont;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The externally defined text font is an external reference to a text font</p> 

<blockquote class=""note"">
NOTE&nbsp; Restrictions of the font source and font names to be used may be exposed by implementation guidelines.
</blockquote> 

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: externally_defined_text_font. Please refer to ISO/IS 10303-46:1994, p. 137 for the final definition of the formal standard.
</blockquote> 

<BLOCKQUOTE class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
307;IfcColourSpecification;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The colour specification entity contains a direct colour definition. Colour component values refer directly to a specific colour space.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: colour_specification. It has been made into an abstract entity in IFC. Please refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
310;IfcColourRgb;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A colour rgb as a subtype of colour specifications is defined by three colour component values for red, green, and blue in the RGB colour model.</p>

<blockquote class=""note"">
NOTE&nbsp; In contrary to the usual value range of colour components being integer from 0...255, the definition from ISO10303-46 defines the colour components as real from 0.0 ... 1.0. Applications need to execute this conversion before populating the colour RGB values.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding STEP name: colour_rgb. The name attribute has been omitted, the data type for the reg, green and blue parts is <i>IfcNormalizedRatioMeasure</i>, that already includes the range restrictions for the values. Please
refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
314;IfcPlanarExtent;"<EPM-HTML>

<p>The planar extent defines the extent along the two axes of the two-dimensional coordinate system, independently of its position.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: planar_extent. Please refer to ISO/IS 10303-46:1994, p. 141 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
318;IfcPlanarBox;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A planar box specifies an arbitrary rectangular box and its location in a two dimensional Cartesian coordinate system.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: planar_box. Please refer to
ISO/IS 10303-46:1994, p. 141 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
324;IfcPropertyDependencyRelationship;"<EPM-HTML> 

<p>An <i>IfcPropertyDependencyRelationship</i> describes an identified dependency between the value of one property and that of another.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Made subtype of <i>IfcResourceLevelRelationship</i> (attribute order changed).
</blockquote>

<p class=""use-head"">Use Definition</p>
<p>Whilst the <i>IfcPropertyDependencyRelationship</i> may be used to describe the dependency, and it may do so in terms of the expression of how the dependency operates, it is not possible through the current IFC model for the value of the related property to be actually derived from the value of the relating property. The determination of value according to the dependency is required to be performed by an application that can then use the Expression attribute to flag the form of the dependency.</p>

</EPM-HTML>"
329;IfcProperty;"<EPM-HTML> 

<p><i>IfcProperty</i> is an abstract generalization for all types of properties that can be associated with IFC objects through the property set mechanism.</p> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC Release 1.0.
</blockquote> 

</EPM-HTML>"
339;IfcComplexProperty;"<EPM-HTML>

<p><i>IfcComplexProperty</i> is used to define complex properties to be handled completely within a property set. The included set of properties may be a mixed or consistent collection of <i>IfcProperty</i> subtypes. This enables the definition of a set of properties to be included as a single 'property' entry in an <i>IfcPropertySet</i>. The definition of such an <i>IfcComplexProperty</i> can be reused in many different <i>IfcPropertySet</i>'s.</p>

<blockquote class=""note"">
NOTE&nbsp; Since an <i>IfcComplexProperty</i> may contain other complex properties, sets of properties can be nested. This nesting may be restricted by view definitions and implementer agreements.
</blockquote>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2.0, capabilities enhanced in IFC Release 2x.
</blockquote>

</EPM-HTML>"
344;IfcSimpleProperty;"<EPM-HTML> 

<p><i>IfcSimpleProperty</i> is a generalization of a single property object. The various subtypes of <i>IfcSimpleProperty</i> establish different ways in which a property value can be set.</p> 

<blockquote class=""history""> 
HISTORY&nbsp; New Entity in IFC Release 1.0, definition changed in IFC Release 2x.
</blockquote>

</EPM-HTML>"
351;IfcPropertySingleValue;"<EPM-HTML> 

<p>The property with a single value
<i>IfcPropertySingleValue</i> defines a property object which has
a single (numeric or descriptive) value assigned. It defines a
property - single value combination for which the property
<i>Name</i>, an optional <i>Description</i>,˙and an optional
<i>NominalValue</i> with measure type is provided. In addition,
the default unit as specified within the project unit context can
be overriden by assigning an <i>Unit</i>.</p>
<p>The unit is handled by the <i>Unit</i> attribute:</p>
<ul>
<li>If the <i>Unit</i> attribute is not given, then the unit is
already implied by the type of <i>IfcMeasureValue</i> or
<i>IfcDerivedMeasureValue</i>. The associated unit can be found
at the <i>IfcUnitAssignment</i> globally defined at the project
level (<i>IfcProject.UnitsInContext</i>).</li>
<li>If the <i>Unit</i> attribute is given, then the unit assigned
by the <i>Unit</i> attribute overrides the globally assigned
unit.</li>
</ul>
<p>Examples of a property with single value are:</p>
<table border=""1"" cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top"">
<td valign=""top"" width=""15%""><b>Name</b></td>
<td valign=""top"" width=""30%""><b>NominalValue</b></td>
<td valign=""top"" width=""25%""><b>Type<br></b> <font size=
""-1"">(through <i>IfcValue</i>)</font></td>
<td valign=""top"" width=""30%""><b>Unit<br></b></td>
</tr>
<tr>
<td width=""15%"">Description</td>
<td width=""30%"">Manufacturer ""A"" door</td>
<td width=""25%""><i>IfcLabel</i></td>
<td width=""30%"">-</td>
</tr>
<tr>
<td width=""15%"">PanelThickness</td>
<td width=""30%"">0.12</td>
<td width=""25%""><i>IfcPositiveLengthMeasure</i></td>
<td width=""30%"">-</td>
</tr>
<tr>
<td width=""15%"">ThermalTransmittance</td>
<td width=""30%"">2.6</td>
<td width=""25%""><i>IfcThermalTransmittanceMeasure</i></td>
<td width=""30%"">W/(m<sup>2</sup>K)</td>
</tr>
</tbody>
</table>
<blockquote class=""history"">
HISTORY&nbsp;˙New entity in IFC Release 1.0. The entity has been renamed from IfcSimpleProperty in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp;˙Attribute <i>NominalValue</i> has been made OPTIONAL with upward compatibility for file based exchange.
</blockquote>

</EPM-HTML>"
354;IfcPropertyEnumeratedValue;"<EPM-HTML> 

<p>A property with an enumerated
value, <i>IfcPropertyEnumeratedValue</i>, defines a property
object which has a value assigned that is chosen from an
enumeration. It defines a property - value combination for which
the˙property <i>Name</i>, an optional <i>Description</i>,˙the
<font color=""#FF0000"">optional</font> <i>EnumerationValues</i>
with measure type and optionally an <i>Unit</i> is given.</p>

<blockquote>
NOTE&nbsp; Multiple choices from the property enumeration are supported.
</blockquote>

<p>The unit is handled by the <i>Unit</i> attribute of the
<i>IfcPropertyEnumeration</i>:</p>
<ul>
<li>If the <i>Unit</i> attribute is not given, then the unit is
already implied by the type of <i>IfcMeasureValue</i> or
<i>IfcDerivedMeasureValue</i>. The associated unit can be found
at the <i>IfcUnitAssignment</i> globally defined at the project
level (<i>IfcProject.UnitsInContext</i>).</li>
<li>If the <i>Unit</i> attribute is given, then the unit assigned
by the unit attribute overrides the globally assigned unit.</li>
</ul>
<p>More precisely: The <i>IfcPropertyEnumeratedValue</i> defines
a property, which value is selected from a defined list of
enumerators. The enumerators are stored in a dynamic enumeration
of values including the type information from <i>IfcValue</i>
(see <i>IfcPropertyEnumeration</i>). This enables applications to
use an enumeration value as a property within a property set
(<i>IfcPropertySet</i>) including the allowed list of
values.˙</p>

<blockquote class=""note"">
NOTE&nbsp; An <i>IfcPropertyEnumeratedValue</i> may be exchanged with no values assigned yet. In this case the <i>EnumerationValues</i> are set to NIL.
</blockquote>

<blockquote>
<p>Examples of a property with enumerated value are:</p>
</blockquote>
<blockquote>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" width=""600"">
<tbody>
<tr valign=""top"">
<td valign=""top"" width=""15%""><b>Name˙</b></td>
<td valign=""top"" width=""30%""><b>Value<br></b> <font size=
""-1"">(EnumerationValue)</font></td>
<td valign=""top""><b>Type<br></b> <font size=""-1"">(through
IfcValue)</font></td>
<td valign=""top"">ref.<b>IfcPropertyEnumeration<br></b>
<font size=""-1"">(Name)</font>˙</td>
</tr>
<tr>
<td>BladeAction</td>
<td>Opposed</td>
<td width=""25%""><i>IfcString</i></td>
<td width=""30%"">DamperBladeActionEnum</td>
</tr>
<tr>
<td>BladeAction</td>
<td>Parallel</td>
<td width=""25%""><i>IfcString</i></td>
<td width=""30%"">DamperBladeActionEnum</td>
</tr>
</tbody>
</table>
<p>The <i>IfcPropertyEnumeratedValue</i> refers to an
<i>IfcPropertyEnumeration</i>, e.g. for the above:</p>
</blockquote>
<blockquote>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" width=""600"">
<tbody>
<tr>
<td width=""30%""><b>Name</b></td>
<td width=""30%""><b>EnumerationValues</b></td>
<td width=""25%""><b>Type<br></b> <font size=""-1"">(through
IfcValue)</font></td>
<td width=""15%""><b>Unit</b></td>
</tr>
<tr>
<td>DamperBladeActionEnum</td>
<td>(Parallel, Opposed, Other, Unset)</td>
<td><i>IfcString</i></td>
<td>-</td>
</tr>
</tbody>
</table>
</blockquote>
<p>It is not mandatory to use an instance of
<i>IfcPropertyEnumeration</i> to hold the applicable values for
<i>IfcPropertyEnumeratedValue</i>, however this is the preferred
way. A single instance of <i>IfcPropertyEnumeration</i> can be
referenced by multiple instances of
<i>IfcPropertyEnumeratedValue</i>.</p>

<blockquote class=""history"">
HISTORY&nbsp;˙New Entity in IFC Release 2.0, capabilities enhanced in IFC2x. The entity has
been renamed from <i>IfcEnumeratedProperty</i> in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Attribute <i>EnumerationValues</i> has been made OPTIONAL with upward
compatibility for file based exchange.
</blockquote>

</EPM-HTML>"
358;IfcPropertyEnumeration;"<EPM-HTML> 

<p><i>IfcPropertyEnumeration</i> is a collection of simple
or measure values that define a prescribed set of alternatives from
which 'enumeration values' are selected. This enables inclusion of
enumeration values in property sets. <i>IfcPropertyEnumeration</i>
provides a name for the enumeration as well as a list of unique
(numeric or descriptive) values (that may have a measure type
assigned). The entity defines the list of potential enumerators to be
exchanged together (or separately) with properties of type <i>IfcPropertyEnumeratedValue</i>
that selects their actual property values from this enumeration. </p>
<p>The unit is handled by the <i>Unit</i> attribute:</p>
<ul>
  <li>If the <i>Unit</i> attribute is not given,
than the unit is already implied by the type of <i>IfcMeasureValue</i>
or <i>IfcDerivedMeasureValue</i>. The associated unit can
be found at the <i>IfcUnitAssignment</i> globally defined
at the project level (<i>IfcProject.UnitsInContext</i>).</li>
  <li> If the <i>Unit</i> attribute is given, the
unit assigned by the unit attribute overrides the globally assigned
unit.</li>
</ul>
<table border=""1"" cellpadding=""2"" cellspacing=""2""
 width=""80%"">
  <tbody>
    <tr>
      <td width=""30%""><b>Name</b></td>
      <td width=""30%""><b>EnumerationValues</b></td>
      <td width=""25%""><b>Type </b><font
 size=""-1"">(through <i>IfcValue</i>)</font></td>
      <td width=""15%""><b>Unit</b></td>
    </tr>
    <tr>
      <td>PEnum_DamperBladeAction</td>
      <td>Parallel</td>
      <td><i>IfcString</i></td>
      <td>-</td>
    </tr>
    <tr>
      <td>&nbsp;</td>
      <td>Opposed</td>
      <td><i>IfcString</i></td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td>&nbsp;</td>
      <td>Other</td>
      <td><i>IfcString</i></td>
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td>&nbsp;</td>
      <td>Unset</td>
      <td><i>IfcString</i></td>
      <td>&nbsp;</td>
    </tr>
  </tbody>
</table>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2.0, capabilities enhanced in IFC Release 2x. Entity has been renamed from IfcEnumeration in IFC Release 2x.
</blockquote>

</EPM-HTML>"
365;IfcPropertyBoundedValue;"<EPM-HTML>
    <p>
      A property with a bounded
      value, <i>IfcPropertyBoundedValue</i>, defines a property
      object which has a maximum of two (numeric or descriptive)
      values assigned, the first value specifying the upper bound
      and the second value specifying the lower bound. It defines
      a property - value bound (min-max) combination for which
      the property <i>Name</i>, an optional
      <i>Description</i>,˙the optional <i>UpperBoundValue</i>
      with measure type, the optional <i>LowerBoundValue</i> with
      measure type, and the optional <i>Unit</i> is given.
    </p>    
    <p>A set point value can be provided in addition to the upper and lower bound values for operational value setting.
    </p>
    <p>
      The unit is handled by the <i>Unit</i> attribute:
    </p>
    <ul>
      <li>If the <i>Unit</i> attribute is not given, then the
      unit is already implied by the type of
      <i>IfcMeasureValue</i> or <i>IfcDerivedMeasureValue</i>.
      The associated unit can be found at the
      <i>IfcUnitAssignment</i> globally defined at the project
      level (<i>IfcProject.UnitsInContext</i>).
      </li>
      <li>If the <i>Unit</i> attribute is given, then the unit
      assigned by the <i>Unit</i> attribute overrides the
      globally assigned unit.
      </li>
    </ul>
    <p>
      The <i>IfcPropertyBoundedValue</i> allows for the
      specification of an interval for the value component of the
      property description. If either the
      <i>LowerBoundValue</i> or the <i>UpperBoundValue</i> is not
      given, then it indicates an open bound (either a minimum
      value or a maximum value). The interval is by definition
      inclusive, that is, the value given for the
      <i>LowerBoundValue</i> or the <i>UpperBoundValue</i> is
      included in the interval.
    </p>
    <blockquote class=""note"">
      NOTE&nbsp; An <i>IfcPropertyBoundedValue</i> may be
      exchanged with no values assigned yet. In this case the
      <i>LowerBoundValue</i> and the <i>UpperBoundValue</i> are
      set to NIL.
    </blockquote>
    <blockquote>
      <p>
        Examples of a property with bounded value are:
      </p>
      <table border=""1"">
        <tbody>
          <tr valign=""top"">
            <td valign=""top"" width=""15%"">
              <b>Name</b>
            </td>
            <td valign=""top"" width=""15%"">
              <b>UpperBoundValue</b>
            </td>
            <td valign=""top"" width=""15%"">
              <b>LowerBoundValue</b>
            </td>
            <td valign=""top"" width=""15%"">
              <b>SetPointValue</b>
            </td>
            <td valign=""top"" width=""45%"">
              <b>Type<br></b> <font size=""-1"">(through
              <i>IfcValue</i>, WR1 ensures same type for both
              values)</font>
            </td>
            <td valign=""top"" width=""10%"">
              <b>Unit<br></b>
            </td>
          </tr>
          <tr valign=""top"">
            <td align=""left"" valign=""top"" width=""15%"">
              OverallHeight
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              1930
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              2300
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              &lt;nil&gt; 
            </td>
            <td align=""left"" valign=""top"" width=""45%"">
              <i>IfcPositiveLengthMeasure</i>
            </td>
            <td align=""left"" valign=""top"" width=""10%"">
              -
            </td>
          </tr>
          <tr valign=""top"">
            <td align=""left"" valign=""top"" width=""15%"">
              OverallWidth
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              0.9
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              1.25
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              &lt;nil&gt; 
            </td>
            <td align=""left"" valign=""top"" width=""45%"">
              <i>IfcPositiveLengthMeasure</i>
            </td>
            <td align=""left"" valign=""top"" width=""10%"">
              m
            </td>
          </tr>
          <tr valign=""top"">
            <td align=""left"" valign=""top"" width=""15%"">
              MaxHeight
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              20.0
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              &lt;nil&gt;
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              &lt;nil&gt; 
            </td>
            <td align=""left"" valign=""top"" width=""45%"">
              <i>IfcPositiveLengthMeasure</i>
            </td>
            <td align=""left"" valign=""top"" width=""10%"">
              -
            </td>
          </tr>
          <tr valign=""top"">
            <td align=""left"" valign=""top"" width=""15%"">
              MinWeight
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              &lt;nil&gt;
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              20
            </td>
            <td align=""left"" valign=""top"" width=""15%"">
              &lt;nil&gt; 
            </td>
            <td align=""left"" valign=""top"" width=""45%"">
              <i>IfcMassMeasure</i>
            </td>
            <td align=""left"" valign=""top"" width=""10%"">
              kg
            </td>
          </tr>
        </tbody>
      </table>
    </blockquote>

<blockquote class=""history"">
HISTORY&nbsp;˙New entity in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x2"">
IFC2x2 CHANGE&nbsp; The attribute type of the attribute <i>UpperBoundValue</i> and <i>LowerBoundValue</i> has been changed from mandatory to optional with upward compatibility for file based exchange.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The attribute <i>SetPointValue</i> has been added.
</blockquote>

    <p>
      Informal proposition:
    </p>
    <ol>
      <li>If the measure type for the upper and lover bound value
      is a numeric measure, then the following shall be true: <i>
        UpperBoundValue</i> &gt; <i>LowerBoundValue</i>.
      </li>
    </ol>

</EPM-HTML>"
373;IfcPropertyTableValue;"<EPM-HTML>
    <p>
      A property with a range value
      (<i>IfcPropertyTableValue</i>) defines a property object
      which has two lists of (numeric or descriptive) values
      assigned, the values specifying a table with two columns.
      The defining values provide the first column and establish
      the scope for the defined values (the second column).
      Interpolations are out of scope of the
      <i>IfcPropertyTableValue</i>. An optional <i>Expression</i>
      attribute may give the equation used for deriving the range
      value, which is for information purposes only.
    </p>
    <p>
      The <i>IfcPropertyTableValue</i> defines a defining/defined
      property value combination for which the property name, the
      table with defining and defined values with measure type
      (and optional the units for defining and defined values)
      are given.
    </p>
    <p>
      The units are handled by the <i>DefiningUnit</i> and
      <i>DefinedUnit</i> attributes:
    </p>
    <ul>
      <li>If the <i>DefiningUnit</i> or <i>DefinedUnit</i>
      attribute is not given, then the unit is already implied by
      the type of <i>IfcMeasureValue</i> or
      <i>IfcDerivedMeasureValue</i>. The associated unit can be
      found at the <i>IfcUnitAssignment</i> globally defined at
      the project level (<i>IfcProject.UnitsInContext</i>).
      </li>
      <li>If the <i>DefiningUnit</i> or <i>DefinedUnit</i>
      attribute is given, then the unit assigned by the unit
      attribute overrides the globally assigned unit.
      </li>
    </ul>
    <p>
      The <i>IfcPropertyTableValue</i> allows for the
      specification of a table of defining/defined value pairs of
      the property description. <font color=""#0000ff"">The optional 
			attribute <i>CurveInterpolation</i> allows to determine the 
			interval between two given values.</font>
    </p>
    <p>
      Examples of a property with range value are:
    </p>
    <table border=""1"" cellpadding=""2"" cellspacing=""2"">
      <tbody>
        <tr valign=""top"">
          <td align=""left"" valign=""top"" width=""20%"">
            <b>Name</b>
          </td>
          <td align=""left"" valign=""top"" width=""10%"">
            <b>DefiningValues</b>
          </td>
          <td align=""left"" valign=""top"" width=""20%"">
            <b>DefiningValue Type<br></b> (through IfcValue)
          </td>
          <td align=""left"" valign=""top"" width=""10%"">
            <b>DefinedValues</b>
          </td>
          <td align=""left"" valign=""top"" width=""20%"">
            <b>DefinedValue Type<br></b> (through
            <i>IfcValue</i>)
          </td>
          <td align=""left"" valign=""top"" width=""10%"">
            <b>DefingUnit</b>
          </td>
          <td align=""left"" valign=""top"" width=""10%"">
            <b>DefinedUnit</b>
          </td>
        </tr>
        <tr>
          <td align=""left"" valign=""top"" width=""20%"">
            SoundTransmissionLoss
          </td>
          <td width=""10%"">
            100
          </td>
          <td width=""20%"">
            <i>IfcFrequencyMeasure</i>
          </td>
          <td width=""10%"">
            20
          </td>
          <td width=""20%"">
            <i>IfcNumericMeasure</i>
          </td>
          <td width=""10%"">
            -
          </td>
          <td width=""10%"">
            dB
          </td>
        </tr>
        <tr valign=""top"">
          <td align=""left"" bgcolor=""#C8C8C8"" valign=""top"" width=
          ""20%"">
            ˙
          </td>
          <td width=""10%"">
            200
          </td>
          <td width=""20%"">
            <i>IfcFrequencyMeasure</i>
          </td>
          <td width=""10%"">
            42
          </td>
          <td width=""20%"">
            <i>IfcNumericMeasure</i>
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
        </tr>
        <tr valign=""top"">
          <td align=""left"" bgcolor=""#C8C8C8"" valign=""top"" width=
          ""20%"">
            ˙
          </td>
          <td width=""10%"">
            400
          </td>
          <td width=""20%"">
            <i>IfcFrequencyMeasure</i>
          </td>
          <td width=""10%"">
            46
          </td>
          <td width=""20%"">
            <i>IfcNumericMeasure</i>
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
        </tr>
        <tr valign=""top"">
          <td align=""left"" bgcolor=""#C8C8C8"" valign=""top"" width=
          ""20%"">
            ˙
          </td>
          <td width=""10%"">
            800
          </td>
          <td width=""20%"">
            <i>IfcFrequencyMeasure</i>
          </td>
          <td width=""10%"">
            56
          </td>
          <td width=""20%"">
            <i>IfcNumericMeasure</i>
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
        </tr>
        <tr valign=""top"">
          <td align=""left"" bgcolor=""#C8C8C8"" valign=""top"" width=
          ""20%"">
            ˙
          </td>
          <td width=""10%"">
            1600
          </td>
          <td width=""20%"">
            <i>IfcFrequencyMeasure</i>
          </td>
          <td width=""10%"">
            60
          </td>
          <td width=""20%"">
            <i>IfcNumericMeasure</i>
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
        </tr>
        <tr valign=""top"">
          <td align=""left"" bgcolor=""#C8C8C8"" valign=""top"" width=
          ""20%"">
            ˙
          </td>
          <td width=""10%"">
            3200
          </td>
          <td width=""20%"">
            <i>IfcFrequencyMeasure</i>
          </td>
          <td width=""10%"">
            65
          </td>
          <td width=""20%"">
            <i>IfcNumericMeasure</i>
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
          <td bgcolor=""#C8C8C8"" width=""10%"">
            ˙
          </td>
        </tr>
      </tbody>
    </table>

<blockquote class=""history"">
HISTORY: New entity in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Attributes <i>DefiningValues</i> and <i>DefinedValues</i> have been made OPTIONAL with upward compatibility for file based exchange. The attribute <i>CurveInterpolation</i> has been added.</font>.</small>
</blockquote>

    <p>
      Informal propositions:
    </p>
    <ol>
      <li>The list of <i>DefinedValues</i> and the list of
      <i>DefiningValues</i> are corresponding lists.
      </li>
    </ol>

</EPM-HTML>"
388;IfcPropertyReferenceValue;"<EPM-HTML> 

    <p><i>IfcPropertyReferenceValue</i> allows a property value to
      be given by referencing other entities within the resource
      definitions of IFC. Those other entities are regarded as
      predefined complex properties and can be aggregated within
      a property set (<i>IfcPropertySet</i>). The allowable
      entities to be used as value references are given by the
      <i>IfcObjectReferenceSelect</i>.</p>
    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC
      Release 1.5. Entity has been renamed from
      IfcObjectReference in IFC Release 2x.
    </blockquote>
    <blockquote class=""change-ifc2x4"">
      IFC2x4 CHANGE&nbsp; Attribute
      <i>PropertyReference</i> has been made OPTIONAL with upward
      compatibility for file based exchange.
    </blockquote>

</EPM-HTML>"
400;IfcPropertyListValue;"<EPM-HTML> 
    <p>
      An <i>IfcPropertyListValue</i>
      defines a property that has several (numeric or
      descriptive) values assigned, these values are given by an
      ordered list.˙It defines a property - list value
      combination for which the property <i>Name</i>, an optional
      <i>Description</i>,˙the optional <i>ListValues</i> with measure
      type and optionally an <i>Unit</i> is given.
    </p>
    <p>
      An <i>IfcPropertyListValue</i> is a list of values. The
      order in which values appear is significant. <s>Each value in
      the list is unique i.e. no duplicate values are allowed.</s>
      All list members shall be of the same type.
    </p>
    <p>
      The unit applicable to all values is handled by the
      <i>Unit</i> attribute:
    </p>
    <ul>
      <li>If the <i>Unit</i> attribute is not given, then the
      unit is already implied by the type of
      <i>IfcMeasureValue</i> or <i>IfcDerivedMeasureValue</i>.
      The associated unit can be found at the
      <i>IfcUnitAssignment</i> globally defined at the project
      level (<i>IfcProject.UnitsInContext</i>).
      </li>
      <li>If the <i>Unit</i> attribute is given, then the unit
      assigned by the <i>Unit</i> attribute overrides the
      globally assigned unit.
      </li>
    </ul>
    <blockquote><p>
      Example of a property with list value is:
    </p>
    <table border=""1"" cellpadding=""2"" cellspacing=""2"" width=
    ""600"">
      <tbody>
        <tr valign=""top"">
          <td valign=""top"" width=""15%"">
            <b>Name</b>
          </td>
          <td valign=""top"" width=""30%"">
            <b>ListValues</b>
          </td>
          <td valign=""top"" width=""25%"">
            <b>Type<br></b> <font size=""-1"">(through
            IfcValue)</font>
          </td>
          <td valign=""top"" width=""30%"">
            <b>Unit<br></b>
          </td>
        </tr>
        <tr>
          <td width=""15%"">
            ApplicableSizes
          </td>
          <td width=""30%"">
            1200
          </td>
          <td width=""25%"">
            <i>IfcPositiveLengthMeasure</i>
          </td>
          <td width=""30%"">
            -
          </td>
        </tr>
        <tr>
          <td width=""15%"">
            -
          </td>
          <td width=""30%"">
            1600
          </td>
          <td width=""25%"">
            <i>IfcPositiveLengthMeasure</i>
          </td>
          <td width=""30%"">
            -
          </td>
        </tr>
        <tr>
          <td width=""15%"">
            -
          </td>
          <td width=""30%"">
            2400
          </td>
          <td width=""25%"">
            <i>IfcPositiveLengthMeasure</i>
          </td>
          <td width=""30%"">
            -
          </td>
        </tr>
      </tbody>
    </table></blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in Release IFC 2x Edition 2.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Attribute <i>ListValues</i> has been made OPTIONAL with upward compatibility for file based exchange.
</blockquote>

</EPM-HTML>"
406;IfcPhysicalQuantity;"<EPM-HTML>

<p>The physical quantity, <i>IfcPhysicalQuantity</i>, is an abstract entity that holds a complex or simple quantity measure together with a semantic definition of the usage for the single or several measure value.</p> 

<p>The <i>Name</i> attribute defines the actual usage or kind of measure. The interpretation of the name label has to be established within the actual exchange context. In addition an informative text may be associated to each quantity by the <i>Description</i> attribute.</p> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>

</EPM-HTML>"
413;IfcPhysicalSimpleQuantity;"<EPM-HTML>

<p>The physical quantity, <i>IfcPhysicalSimpleQuantity</i>, is an entity that holds a single quantity measure value (as defined at the subtypes of <i>IfcPhysicalSimpleQuantity</i>) together with a semantic definition of the usage for the measure value.</p> 

<blockquote class=""example"">
EXAMPLE&nbsp; An element, like a wall, may have several area measures, like footprint area, left wall face area, right wall face area. These areas would be given by three instances of the area quantity subtype, with different <I>Name</I> string values.
</blockquote>

<p>A section ""Quantity Use Definition"" at individual entities as subtypes of <i>IfcBuildingElement</i> gives guidance to the usage of the <i>Name</i> attribute to characterize the individual quantities. If the <i>Unit</i> attribute is given, the value attribute (introduced at the level of subtypes of <i>IfcPhysicalSimpleQuantity</i>) are given as quantities of this unit, otherwise the global unit definitions (given by <i>IfcUnitAssignment</i>) are used.</p>

<blockquote class=""history""> 
HISTORY New entity in IFC2x2 Addendum 1.
</blockquote>

<blockquote class=""change-ifc2x2""> 
IFC2x2 ADDENDUM 1 CHANGE&nbsp; The abstract entity <i>IfcPhysicalSimpleQuantity</i> has been added. Upward compatibility for file based exchange is guaranteed.
</blockquote>

</EPM-HTML>"
421;IfcQuantityLength;"<EPM-HTML> 

<p><i>IfcQuantityLength</i> is a physical quantity that defines a derived length measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>

<blockquote class=""example"">
EXAMPLE&nbsp; A rafter within a roof construction may be measured according to its length (taking a common cross section into account). The actual size of the length depends on the method of measurement used.
</blockquote> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC Release 2.x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote> 

</EPM-HTML>"
426;IfcQuantityArea;"<EPM-HTML> 

<p><i>IfcQuantityArea</i> is a physical quantity that defines a derived area measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p> 

<blockquote class=""example"">
EXAMPLE&nbsp; An opening may have an opening area used to deduct it from the wall surface area. The actual size of the area depends on the method of measurement used.
</blockquote> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
 
</EPM-HTML>"
431;IfcQuantityVolume;"<EPM-HTML> 

<p><i>IfcQuantityVolume</i> is a physical quantity that defines a derived volume measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p> 

<blockquote class=""example"">
EXAMPLE&nbsp; A thick brick wall may be measured according to its volume. The actual size of the volume depends on the method of measurement used.
</blockquote> 

<blockquote class=""history""> 
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>

</EPM-HTML>"
436;IfcQuantityCount;"<EPM-HTML> 

<p><i>IfcQuantityCount</i> is a physical quantity that defines a derived count measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>

<blockquote class=""example"">
EXAMPLE&nbsp; An radiator may be measured according to its number of coils. The actual counting method depends on the method of measurement used.
</blockquote> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>

</EPM-HTML>"
440;IfcQuantityWeight;"<EPM-HTML> 

<p><i>IfcQuantityWeight</i> is a physical element quantity that defines a derived weight measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p> 

<blockquote class=""example"">
EXAMPLE&nbsp; The amount of reinforcement used within a building element may be measured according to its weight. The actual size of the weight depends on the method of measurement used.
</blockquote> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>

</EPM-HTML>"
445;IfcQuantityTime;"<EPM-HTML>

<p><i>IfcQuantityTime</i> is an element quantity that defines a time measure to provide an property of time related to an element. It is normally given by the recipe information of the element under the specific measure rules given by a method of measurement.</p>

<blockquote class=""example"">
EXAMPLE&nbsp; The amount of time needed to pour concrete for a wall is given as a time quantity for the labor part of the recipe information.
</blockquote> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
450;IfcPhysicalComplexQuantity;"<EPM-HTML>

<p>The complex physical quantity, <i>IfcPhysicalComplexQuantity</i>, is an entity that holds a set of single quantity measure value (as defined at the subtypes of <i>IfcPhysicalSimpleQuantity</i>), that all apply to a given component or aspect of the element.</p> 

<blockquote class=""example"">
EXAMPLE: A layered element, like a wall, may have several material layers, each having individual quantities, like footprint area, side area and volume. An instance of <i>IfcPhysicalComplexQuantity</i> would group these individual quantities (given by a subtype of <i>IfcPhysicalSimpleQuantity</i>) and name them according to the material layer name by using the <i>Name</i> attribute. The <i>Discrimination</i> attribute would then be 'layer'.
</blockquote>

<p>A section ""Quantity Use Definition"" at individual entities as subtypes of <i>IfcBuildingElement</i> gives guidance to the usage of the <i>Name</i> and <i>Discrimination</i> attribute to characterize the complex quantities.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2 Addendum 1.
</blockquote>

<blockquote class=""change-ifc2x2"">
IFC2x2 ADDENDUM 1 CHANGE&nbsp; The entity <i>IfcPhysicalComplexQuantity</i> has been added. Upward compatibility for file based exchange is guaranteed.
</blockquote>

</EPM-HTML>"
459;IfcSystem;"<EPM-HTML> 
    <p>
      <u>Definition from IAI</u>: Organized combination of
      related parts within an AEC product, composed for a common
      purpose or function or to provide a service. System is
      essentially a functionally related aggregation of products.
      The grouping relationship to one or several instances of
      <i>IfcProduct</i> (the system members) is handled by
      <i>IfcRelAssignsToGroup</i>.
    </p>
    <blockquote>
      <font size=""-1"">NOTE: The use of <i>IfcSystem</i> often
      applies to the representation of building services related
      systems, such as the piping system, cold water system, etc.
      Members within such a system may or may not be connected
      using the connectivity related entities (e.g. through
      <i>IfcPort</i>).</font>
    </blockquote>
    <blockquote>
      <p>
        <font color=""#0000FF"" size=""-1"">HISTORY: New entity in
        IFC Release 1.0</font>
      </p>
    </blockquote>
</EPM-HTML>"
464;IfcZone;"<EPM-HTML> 
<p><u>Definition from IAI</u>: A zone is˙a group of spaces,
partial spaces or other zones. Zone structures may not be
hierarchical (in contrary to the spatial structure of a project -
see <i>IfcSpatialStructureElement</i>), i.e. one individual
<i>IfcSpace</i> may be associated with zero, one, or several
<i>IfcZone</i>'s. <i>IfcSpace</i>'s are grouped into an
<i>IfcZone</i> by using the objectified relationship
<i>IfcRelAssignsToGroup</i> as specified at the supertype
<i>IfcGroup</i>.</p>
<blockquote><small>NOTE ˙Certain use cases may restrict the
freedom of non hierarchical relationships. In some building
service use cases the zone denotes a˙view based delimited volume
for the purpose of analysis and calculation. This type of zone
cannot overlap with respect to that analysis, but may overlap
otherwise.</small></blockquote>
<p>An <i>IfcZone</i> is a spatial system under which individual
<i>IfcSpace</i>'s (and other <i>IfcZone</i>'s) are grouped. In
contrary to the <i>IfcSpatialZone</i> entity, <i>IfcZone</i> is a
mere grouping, it can not define an own geometric representation
and placement. Therefore it cannot be used for spatial zones
having a different shape and size compared to the shape and size
of aggregated spaces.</p>
<blockquote><small>NOTE˙ The <i>IfcZone</i> is regarded as the
spatial system (as compared to the building service, electrical,
or analytical system), the name remains <i>IfcZone</i> for
compatibility reasons, instead of using a proper naming
convention, like IfcSpatialSystem.</small></blockquote>
<blockquote><small>NOTE ˙One of the purposes of a zone is to
define a fire compartmentation. In this case it defines the
geometric information about the fire compartment (through the
contained spaces) and information, whether this compartment is
ventilated or sprinkler protected. In addition the fire risk code
and the hazard type can be added, the coding is normally defined
within a national fire regulation. All that information is
available within the relevant property sets. Again, if an
independent shape has to be provided to the fire compartment,
then the entity <i>IfcSpatialZone</i> shall be
used.</small></blockquote>
<blockquote><small>RECOMMENDATION˙ In case of a zone denoting a
(fire) compartment, the following types should be used, if
applicable, as values of the <i>ObjectType</i> attribute:</small>
<ul>
<li><small>FireCompartment - a zone of spaces, collected to
represent a single fire compartment.</small></li>
<li><small>ElevatorShaft - a collection of spaces within an
elevator, potentially going through many storeys.</small></li>
<li><small>RisingDuct</small></li>
<li><small>RunningDuct</small></li>
</ul>
</blockquote>
<p>Additional classifications of the <i>IfcZone</i>, as provided
by a national classification system, can be assigned by using the
<i>IfcRelAssociatesClassification</i> relationship, accessible
via the inverse attribute <i>HasAssociations</i>. The
<i>IfcZone</i> can be assigned to a spatial structure element, it
refers to, e.g. to a particular <i>IfcBuildingStorey</i> by using
the <i>IfcRelServicesBuildings</i> relationship, accessible via
the inverse attribute <i>ServicesBuilding</i>.</p>
<blockquote><small><font color=""#0000FF"">HISTORY˙ New entity in
IFC Release 1.0</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE˙ The entity is now
subtyped from <i>IfcSystem</i> (not its supertype
<i>IfcGroup</i>) with upward compatibility for file based
exchange.</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcZone</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcZone</i> are part
of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcProductExtension/Pset_ZoneCommon.xml""
target=""SOURCE"">Pset_ZoneCommon</a>: common property set for all
types of zone</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceFireSafetyRequirements.xml""
target=""SOURCE"">Pset_SpaceFireSafetyRequirements</a>: common
property set for all types of zones to capture the fire safety
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceLightingRequirements.xml""
target=""SOURCE"">Pset_SpaceLightingRequirements</a>: common
property set for all types of zones to capture the lighting
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceOccupancyRequirements.xml""
target=""SOURCE"">Pset_SpaceOccupancyRequirements</a>: common
property set for all types of zones to capture the occupancy
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceThermalRequirements.xml""
target=""SOURCE"">Pset_SpaceThermalRequirements</a>: common
property set for all types of zones to capture the thermal
requirements</li>
</ul>
</EPM-HTML>"
467;IfcRelConnectsElements;"<EPM-HTML> 
    <p>
      <u>Definition from IAI</u>: The
      <i>IfcRelConnectsElements</i> objectified relationship
      provides the generalization of the connectivity between
      elements. It is a 1 to 1 relationship. The concept of two
      elements being physically or logically connected is
      described independently from the connecting elements. The
      connectivity may be related to the shape representation of
      the connected entities by providing a connection geometry.
    </p>
    <ul>
      <li>In this case the geometrical constraints of the
      connection are provided by the optional relationship to the
      <i>IfcConnectionGeometry</i>. The connection geometry is
      provided as a point, curve or surface within the local
      placement coordinate systems of the connecting elements.
      </li>
      <li>If the connection geometry is omitted then the
      connection is provided as a logical connection. Under this
      circumstance, the connection point, curve or surface has to
      be recalculated by the receiving application.
      </li>
    </ul>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in IFC
        Release 1.0.</font></small>
      </p>
    </blockquote>
</EPM-HTML>"
474;IfcRelSpaceBoundary;"<EPM-HTML> 
<p>The space boundary defines the
physical or virtual delimiter of a space by the relationship
<i>IfcRelSpaceBoundary</i> to the surrounding elements.</p>
<ul>
<li>In the case of a physical space boundary, the placement and
shape of the boundary may be given, and the building element,
providing the boundary, is referenced,</li>
<li>In the case of a virtual space boundary, the placement and
shape of the boundary may be given, <s>but no building element is
referenced</s> <font color=""#0000FF"">and a virtual element is
referenced instead</font>.</li>
</ul>
<p>The <i>IfcRelSpaceBoundary</i> is defined as an objectified
relationship that handles the element to space relationship by
objectifying the relationship between an element and the space it
bounds. It is given as a one-to-one relationship, but allows each
element (including virutal elements and openings) to define many
such relationship and each space to be defined by many such
relationships.</p>
<p>Space boundaries are always defined as seen from the space. In
general two basic types of space boundaries are
distinguished:</p>
<ul>
<li>1<sup><small>st</small></sup> level space boundary: defined
as boundaries of the space, not taking into account any change in
building element or spaces on the other side.</li>
<li>2<sup><small>nd</small></sup> level space boundary: defined
as boundary taking any change in building element or spaces on
the other side into account. It can be further distinguished into
<ul>
<li>2<sup><small>nd</small></sup> level type A: There is a space
on the other side.</li>
<li>2<sup><small>nd</small></sup> level type B: There is a
building element on the other side.</li>
</ul>
</li>
</ul>
<blockquote><small>The exact definition of how space boundaries
are broken down depends on the view definition, more detailed
conventions on how space boundaries are decomposed can only be
given at the domain or application type level.</small>
<ul>
<li><small>In an architectural or FM related view, a space
boundary is defined totally from inside the space. This is a
1<sup><small>st</small></sup> level space boundary.</small></li>
<li><small>In a thermal view, the decomposition of the space
boundary depends on the material of the providing building
element and the adjacent spaces behind. This is a
2<sup><small>nd</small></sup> level space boundary.</small></li>
</ul>
</blockquote>
<table summary=""space boundary types"" border=""0"">
<tr>
<td><img src=""figures/IfcRelSpaceBoundary_1stLevel.png"" alt=
""1st level""></td>
<td><img src=""figures/IfcRelSpaceBoundary_2ndLevel.png"" alt=
""2nd level""></td>
</tr>
<tr>
<td><p class=""figure"">Figure 42 &mdash; Space boundary at first level</p></td>
<td><p class=""figure"">Figure 43 &mdash; Space boundary at second level</p></td>
</tr>
<tr>
<td><img src=""figures/IfcRelSpaceBoundary_2ndLevel_TypeA.png""
alt=""2nd level type a""></td>
<td><img src=""figures/IfcRelSpaceBoundary_2ndLevel_TypeB.png""
alt=""2nd level type b""></td>
</tr>
<tr>
<td><p class=""figure"">Figure 44 &mdash; Space boundary at second level type A</p></td>
<td><p class=""figure"">Figure 45 &mdash; Space boundary at second level type B</p></td>
</tr>
</table>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.5, the entity has been modified in IFC Release
2x.</blockquote>
<blockquote class=""change-ifc2x"">IFC2x CHANGE The data type of the attribute<i>RelatedBuildingElement</i> has
been changed from <i>IfcBuildingElement</i> to its supertype <i>IfcElement</i>. The data type of the attribute
<i>ConnectionGeometry</i> has been changed from <i>IfcConnectionSurfaceGeometry</i> to its supertype
<i>IfcConnectionGeometry</i>.</blockquote>
<blockquote class=""change-ifx2x4"">IFC2x4 CHANGE The attribute <i>RelatedBuildingElement</i> has been made mandatory. For virtual boundaries the reference to <i>IfcVirtualElement</i> is now mandatory.</font></small></blockquote>

<p class=""use-head"">Attribute Use Definitions</p>
<p>The differences between the 1<sup><small>st</small></sup> and
2<sup><small>nd</small></sup> level space boundaries is
identified by:</p>
<ul>
<li><b>1<sup><small>st</small></sup> level:</b><br>
SELF\IfcRoot.Name = ""1stLevel""<br>
SELF\IfcRootDescription = NIL</li>
<li><b>2<sup><small>nd</small></sup> level:</b><br>
SELF\IfcRoot.Name = ""2ndLevel""<br>
SELF\IfcRootDescription = ""2a"", or ""2b""</li>
</ul>
<p>Differentiation between physical and virtual space boundary is illustrated in Figure 46 and Figure 47.</p>

<p>As shown in Figure 46, if the <i>IfcRelSpaceBoundary</i> is used to express a virtual boundary, the attribute <i>PhysicalOrVirtualBoundary</i> has to be set to VIRTUAL. The attribute <i>RelatedBuildingElement</i> shall point to an instance of <i>IfcVirtualElement</i>. If the correct location is of interest, the attribute <i>ConnectionGeometry</i> is required.</p>
<blockquote class=""note"">NOTE The connection geometry, either by a 2D curve or a 3D surface, is used to describe the portion of the ""virtual wall"" that separates the two spaces. All instances of <i>IfcRelSpaceBoundary</i> given at the adjacent spaces share the same instance of <i>IfcVirtualElement</i>. Each instance of <i>IfcRelSpaceBoundary</i> provides in addition the <i>ConnectionGeometry</i> given within the local placement of each space.</blockquote>

<table summary=""virtual"">
<tr><td><img alt=""IfcRelSpaceBoundary_virtual (35K)"" src=""figures/IfcRelSpaceBoundary_virtual.png"" height=""500"" width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 46 &mdash; Space boundary of virtual element</p></td></tr>
</table>

<p>As shown in Figure 47, if the <i>IfcRelSpaceBoundary</i> is used to express a physical boundary between two spaces, the attribute <i>PhysicalOrVirtualBoundary</i> has to be set to PHYSICAL. The attribute <i>RelatedBuildingElement</i> has to be given and points to the element providing the space boundary. The attribute <i>ConnectionGeometry</i> may be inserted, in this case it describes the physical space boundary geometically, or it may be omited, in that case it describes a physical space boundary logically.</p>

<table summary=""physical"">
<tr><td><img alt=""IfcRelSpaceBoundary_physical (35K)"" src=""figures/IfcRelSpaceBoundary_physical.png"" height=""500"" width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 47 &mdash; Space boundary of physical element</p></td></tr>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The <i>IfcRelSpaceBoundary</i> may have geometry attached. If
geometry is not attached, the relationship between space and
building element is handled only on a logical level. If geometry
is attached, it is given within the local coordinate systems of
the space.</p>
<blockquote><small>NOTE: The attributes
<i>CurveOnRelatingElement</i> at
<i>IfcConnectionCurveGeometry</i> or
<i>SurfaceOnRelatingElement</i> at
<i>IfcConnectionSurfaceGeometry</i> provide the geometry within
the local coordinate system of the <i>IfcSpace</i>, whereas the
attributes <i>CurveOnRelatedElement</i> at
<i>IfcConnectionCurveGeometry</i> or
<i>SurfaceOnRelatedElement</i> at
<i>IfcConnectionSurfaceGeometry</i> provide the geometry within
the local coordinate system of the subtype of
<i>IfcElement</i></small>.<br>
<small>NOTE In most view definitions the connection geometry for
the related <i>IfcElement</i> is not
provided.</small></blockquote>
<p>The geometric representation (through the
<i>ConnectionGeometry</i> attribute) is defined using either 2D
curve geometry or 3D surface geometry for space boundaries. In
most view definitions the 3D connection surface geometry is
required.</p>
<ul>
<li>1<sup><small>st</small></sup> level space boundary:
<ul>
<li>only connection geometry for related space shall be
provided</li>
<li>only surface connection geometry shall be provided</li>
<li>only the following surface representations are supported:
<ul>
<li><i>IfcSurfaceOfLinearExtrusion</i></li>
<li><i>IfcCurveBoundedPlane</i></li>
<li><i>IfcCurveBoundedSurface</i></li>
<li><i>IfcFaceBasedSurfaceModel</i></li>
</ul>
</li>
</ul>
</li>
<li>2<sup><small>nd</small></sup> level space boundary:
<ul>
<li>only connection geometry for related space shall be
provided</li>
<li>only surface connection geometry shall be provided</li>
<li>only the following surface representations are supported:
<ul>
<li><i>IfcCurveBoundedPlane</i> with restrictions to have
polygonal boundaries only</li>
<li><i>IfcFaceBasedSurfaceModel</i></li>
</ul>
</li>
</ul>
</li>
</ul>
<p><b>Surface connection geometry</b></p>
<p>The following constraints apply to the surface connection
geometry representation:</p>
<ul>
<li>planar boundaries:
<ul>
<li><i>IfcSurfaceOfLinearExtrusion</i> defined by a
<i>SweptCurve</i> being an <i>IfcArbitraryOpenProfileDef</i> with
straight segements, or</li>
<li><i>IfcCurveBoundedPlane</i></li>
</ul>
</li>
<li>curved boundaries
<ul>
<li><i>IfcSurfaceOfLinearExtrusion</i> defined by a
<i>SweptCurve</i> being an <i>IfcArbitraryOpenProfileDef</i> with
curves segements, or</li>
<li><i>IfcCurveBoundedSurface</i> with a <i>BasisSurface</i>
being a non planar surface, such as <i>IfcCylindricalSurface</i>,
or</li>
<li><i>IfcFaceBasedSurfaceModel</i> if already faceted.</li>
</ul>
</li>
</ul>
<p><b>Curve connection geometry</b></p>
<p>The following constraints apply to the 2D curve
representation:</p>
<ul>
<li>Curve: <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i> or
<i>IfcCompositeCurve</i></li>
</ul>
</EPM-HTML>"
483;IfcRelSpaceBoundary1stLevel;"<EPM-HTML>
<p>The 1st level space boundary
defines the physical or virtual delimiter of a space by the
relationship <i>IfcRelSpaceBoundary1stLevel</i> to the
surrounding elements. 1st level space boundaries are
characterizeda by:</p>
<ul>
<li>1st level space boundaries are the boundaries of a space
defined by the surfaces of building elements bounding this space
(physical space boundaries) or by virtual surfaces provided by an
adjacent space with no dividing wall.</li>
<li>1st level space boundaries do not consider any change of
material in the bounding building elements, or different
spaces/zones behind a wall or slab (floor or ceiling).</li>
<li>1st level space boundaries are differentiated in two ways:
virtual or physical and internal,external, or undefined (internal
and external) e.g. for a wall that is partially inside and
outside.</li>
<li>1st level space boundaries form a closed shell around the
space (so long as the space is completely enclosed) and include
overlapping boundaries representing openings (filled or not) in
the building elements (see implementers agreement below).</li>
</ul>
<p>1st level space boundaries define a space by its boundary
surfaces without taking anything on the other side of the
bounding elements into account.</p>
<blockquote><small>NOTE 1st level space boundaries are used e.g.
in quantity take-off and facility management as they describe the
surfaces for finishes. They cannot be directly used for thermal
analysis. However 1st level space boundaries can provide the
input to preprocessors to thermal analysis software that take 1st
level space boundaries and perform the necessary transformation
into 2nd level space boundaries that are required for energy
analysis.</small></blockquote>

<blockquote class=""history"">HISTORY New entity in IFC2x4.</blockquote>

<p class=""use-head"">Relationship Use Definitions</p>

<p>As shown in Figure 48, the attribute <i>ParentBoundary</i> with inverse <i>InnerBoundaries</i> is provided to link the space boundaries of doors, windows, and openings to the parent boundary, such as of a wall or slab.</p>
<blockquote class=""note"">NOTE The space boundary of the parent is not cut by the inner boundary - both overlap.</blockquote>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=
""parent/inner boundaries"">
<tr><td><img alt=""IfcRelSpaceBoundary1stLevel"" src=
""figures/IfcRelSpaceBoundary1stLevel-fig1.png"" height=""550""
width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 48 &mdash; Space boundary first level relationships</p></td></tr>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>See the definition at the supertype IfcRelSpaceBoundary for
guidance on using the connection geometry for first level space
boundaries.</p>

</EPM-HTML>"
486;IfcRelSpaceBoundary2ndLevel;"<EPM-HTML>
<p>The 2nd level space boundary defines the physical or virtual delimiter of a space by the relationship <i>IfcRelSpaceBoundary2ndLevel</i> to the surrounding elements. 2nd level space boundaries are characterized by:</p>
<ul>
<li>2nd level space boundaries still represent building elements that bound the space, but are more granular in that they are subdivided in any of the following cases:
<ul>
<li>Differences in materials and/or material assemblies (for example, a wainscot or paneling on the lower portion of a wall).</li>
<li>Differences in spaces or zones on the other side of the building element (or virtual boundary) represented by the space boundary (for example, two different spaces on the other side of a wall)</li>
</ul>
</li>
<li>2nd level space boundaries are differentiated in two ways: virtual or physical and internal or external, whereby any space boundary that is both internal and external has to be split into segments being either or.</li>
<li>2nd level space boundaries represent both sides of a heat transfer surface separated by the thickness of the building element. They can be further differentiated in:
<ul>
<li>Type 2a that occurs when there is a space on the opposite side of the building element providing the space boundary</li>
<li>Type 2b occurs if there is a building element on the opposite side of the building element providing the space boundary.</li>
</ul>
</li>
<li>The connection geometry of 2nd level space boundaries is restricted to planar surfaces only. This means that curved surfaces must be segmented.</li>
</ul>
<p>2nd level space boundaries define the heat transfer surfaces on both sides of building elements that separate spaces. The generation of 2nd level space boundaries has to take building elements and spaces on the other side into account.</p>
<blockquote class=""note"">NOTE 2nd level space boundaries are used by many analysis packages that require a surface view of the building that can be transformed into the various simple topological models. Examples of such analysis packages include: (1) energy analysis, (2) lighting analysis, (3) fluid dynamics</blockquote>

<blockquote class=""history"">HISTORY New entity in IFC2x4.</font></small></blockquote>

<p class=""use-head"">Relationship Use Definitions</p>
<p>As shown in Figure 49, the attribute <i>ParentBoundary</i> with inverse <i>InnerBoundaries</i> is provided to link the space boundaries of doors, windows, and openings to the parent boundary, such as of a wall or slab.</p>
<blockquote class=""note"">NOTE The space boundary of the parent is not cut by the inner boundary - both overlap.</blockquote>
<p>The attribute <i>CorrespondingBoundary</i> with inverse <i>Corresponds</i> is provided to link the pair of space boundaries on the opposite sides of the building element.</p>
<blockquote class=""note"">NOTE Only 2nd level space boundaries of type A have corresponding boundaries.</blockquote>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""parent/inner boundaries"">
<tr><td><img alt=""IfcRelSpaceBoundary2ndLevel"" src=""figures/IfcRelSpaceBoundary2ndLevel-fig1.png"" height=""650"" width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 49 &mdash; Space boundary second level relationships</p></td></tr>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>See the definition at the supertype <i>IfcRelSpaceBoundary</i>
for guidance on using the connection geometry for second level
space boundaries.</p>

</EPM-HTML>"
494;IfcSpace;"<EPM-HTML> 
<p>A space represents an area or volume
bounded actually or theoretically. Spaces are areas or volumes that
provide for certain functions within a building.</p>
<p>A space is associated to a building storey (or in case of
exterior spaces to a site). A space may span over several connected
spaces. Therefore a space group provides for a collection of spaces
included in a storey. A space can also be decomposed in parts,
where each part defines a partial space. This is defined by the
<i>CompositionType</i> attribute of the supertype
<i>IfcSpatialStructureElement</i> which is interpreted as
follow:</p>
<ul>
<li>COMPLEX = space group</li>
<li>ELEMENT = space</li>
<li>PARTIAL = partial space</li>
</ul>
<blockquote><small>NOTE View definitions and implementation
agreements may restrict spaces with <i>CompositionType</i>=ELEMENT
to be non-overlapping.</small></blockquote>
<p>The following guidelines should apply for using the <i>Name</i>,
<i>Description</i>, <i>LongName</i> and <i>ObjectType</i>
attributes.</p>
<ul>
<li><i>Name</i> holds the unique name (or space number) from the
plan.</li>
<li><i>Description</i> holds any additional information field the
user may have specified, there are no further recommendations.</li>
<li><i>LongName</i> holds the full name of the space, it is often
used in addition to the <i>Name</i>, if a number is assigned to the
room, then the descriptive name is exchanged as
<i>LongName</i>.</li>
<li><i>ObjectType</i> holds the space type, i.e. usually the
functional category of the space .</li>
</ul>
<blockquote class=""history"">HISTORY New Entity in IFC Release 1.0</blockquote>

<p class=""use-head"">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcSpace</i> are defined by
the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcSpace</i> are part of this
IFC release:</p>
<ul>
<li><a href=""../../psd/IfcProductExtension/Pset_SpaceCommon.xml""
target=""SOURCE"">Pset_SpaceCommon</a>: common property set for all
types of spaces
<ul>
<li><a href=""../../psd/IfcProductExtension/Pset_SpaceParking.xml""
target=""SOURCE"">Pset_SpaceParking</a>: specific property set for
only those spaces that are used to define parking spaces by
<i>PredefinedType</i>: PARKING</li>
</ul>
</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceFireSafetyRequirements.xml""
target=""SOURCE"">Pset_SpaceFireSafetyRequirements</a>: common
property set for all types of spaces to capture the fire safety
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceLightingRequirements.xml""
target=""SOURCE"">Pset_SpaceLightingRequirements</a>: common property
set for all types of spaces to capture the lighting
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceOccupancyRequirements.xml""
target=""SOURCE"">Pset_SpaceOccupancyRequirements</a>: common
property set for all types of spaces to capture the occupancy
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceThermalRequirements.xml""
target=""SOURCE"">Pset_SpaceThermalRequirements</a>: common property
set for all types of spaces to capture the thermal
requirements</li>
<li><a href=
""../../psd/IfcSharedBldgServiceElements/Pset_SpaceThermalDesign.xml""
target=""SOURCE"">Pset_SpaceThermalDesign</a>: common property set
for all&nbsp;all types of spaces to capture building service design
values</li>
</ul>

<p class=""use-head"">Quantity Use Definition</p>
<p>The quantities relating to the <i>IfcSpace</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
""../../qto/IfcProductExtension/Qto_SpaceBaseQuantities.xml"" target=
""SOURCE"">Qto_SpaceBaseQuantities</a>: base quantities for all space
occurrences.</li>
</ul>

<p class=""use-head"">Spatial Structure Use Definition</p>
<p>The <i>IfcSpace</i> is used to build the spatial structure of a
building (that serves as the primary project breakdown and is
required to be hierarchical). The spatial structure elements are
linked together by using the objectified relationship
<i>IfcRelAggregates</i>. The <i>IfcSpace</i> references them by its
inverse relationships:</p>
<ul>
<li><i>IfcSpace.Decomposes</i> -- referencing (<i>IfcSite</i> ||
<i>IfcBuildingStorey</i> || <i>IfcSpace</i>) by
<i>IfcRelAggregates.RelatingObject</i>, If it refers to another
instance of&nbsp;<i>IfcSpace</i>, the referenced <i>IfcSpace</i>
needs to have a different and higher <i>CompositionType</i>, i.e.
COMPLEX (if the other <i>IfcSpace</i> has ELEMENT), or ELEMENT (if
the other <i>IfcSpace</i> has PARTIAL).</li>
<li><i>IfcSpace.IsDecomposedBy</i> -- referencing (<i>IfcSpace</i>)
by <i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of <i>IfcSpace</i>, the referenced <i>IfcSpace</i> needs
to have a different and lower <i>CompositionType</i>, i.e. ELEMENT
(if the other <i>IfcSpace</i> has COMPLEX), or PARTIAL (if the
other <i>IfcSpace</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcSpace</i>&nbsp;(like most furniture and
distribution elements), they are associated with the
<i>IfcSpace</i> by using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>. The <i>IfcSpace</i>
references them by its inverse relationship:</p>
<ul>
<li><i>IfcSpace.ContainsElements</i> -- referencing any subtype of
<i>IfcProduct</i> (with the exception of other spatial structure
element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>

<p>Figure 57 shows the <i>IfcSpace</i> as part of the spatial structure. It also serves as the spatial container for space related elements.</p>
<blockquote class=""note"">NOTE Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.</blockquote>

<table summary=""spatial structure"" cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top""><img src=""figures/IfcSpace-SpatialStructure.png"" alt=""spatial structure"" border=""0"" height=""350"" width=""800""></td></tr>
<tr><td><p class=""figure"">Figure 57 &mdash; Space composition</p></td></tr>
</table>

<p class=""use-head"">Attribute Use Definition</p>

<p>Figure 58 describes the heights and elevations of the <i>IfcSpace</i>.</p>
<ul>
<li>elevation of the space (top of construction slab) equals elevation of storey: provided by <i>IfcBuildingStorey.Elevation</i> relative to <i>IfcBuilding.ElevationOfRefHeight</i></li>
<li>elevation of the space flooring (top of flooring on top of slab): provided by <i>IfcSpace.ElevationWithFlooring</i> relative to <i>IfcBuilding.ElevationOfRefHeight</i></li>
<li>height of space (top of slab below to bottom of slab above): provided by BaseQuantity with Name=""Height""</li>
<li>floor height of space (top of slab below to top of flooring): provided by BaseQuantity with Name=""FinishFloorHeight""</li>
<li>net height of space (top of flooring to bottom of suspended ceiling): provided by BaseQuantity with Name=""FinishCeilingHeight""</li>
</ul>

<table summary=""attributes"" cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top""><img src=
""figures/IfcSpace_Heights.png"" alt=""space heights"" border=""0""
height=""400"" width=""450""></td></tr>
<tr><td><p class=""figure"">Figure 58 &mdash; Space elevations</p></td></tr>
</table>

<p class=""use-head"">Geometry Use Definition</p>
<p>The geometric representation of <i>IfcSpace</i> is given by the
<i>IfcProductDefinitionShape</i> and <i>IfcLocalPlacement</i>
allowing multiple geometric representations.</p>
<blockquote class=""note"">NOTE In cases of inconsistency between the
geometric representation of the <i>IfcSpace</i> and the combined
geometric representations of the surrounding
<i>IfcRelSpaceBoundary</i>, the geometric representation of the
space should take priority over the geometric representation of the
surrounding space boundaries.</blockquote>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcSpace</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement of the
<i>IfcSpatialStructureElement</i> of type ""IfcBuildingStorey"", if
relative placement is used, or of type ""IfcSpace"" (e.g. to position
a space relative to a space group, or a partial space to a
space).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'Curve2D' or 'GeometricCurveSet' and a 3D 'Body' representation of
type 'SweptSolid, 'Clipping' and 'Brep' is supported.</p>
<p><b>'Foot Print' Representation</b></p>
<p>The 2D geometric representation of <i>IfcSpace</i> is defined
using the 'Curve2D' or 'GeometricCurveSet' geometry. The following
attribute values should be inserted</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> = 'Curve2D' or
'GeometricCurveSet' .</li>
</ul>
<p>The following constraints apply to the 2D representation:</p>
<ul>
<li><u>Profile</u>: <i>IfcBoundedCurve</i> is required, using
<i>IfcPolyline</i> for faceted space contours or
<i>IfcCompositeCurve</i> for space contours with arc segments. For
spaces with inner boundaries, a set of <i>IfcBoundedCurve</i>'s is
used, that should be grouped into an
<i>IfcGeometricCurveSet</i>.</li>
</ul>

<p>Figure 59 shows a two-dimensional bounded curve representing the
foot print of <i>IfcSpace</i>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcSpace_2D-Layout1.gif"" alt=""2d representation"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 59 &mdash; Space footprint</p></td></tr>
</table>

<p><b>'Swept Solid' Representation</b></p>
<p>The standard geometric representation of <i>IfcSpace</i> is
defined using the swept area solid geometry. The following
attribute values should be inserted</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'SweptSolid'.</li>
</ul>
<p>The following constraints apply to the standard
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef</i> is
required, <i>IfcArbitraryProfileDefWithVoids</i> shall be
supported.</li>
<li><u>Extrusion</u>: The extrusion direction shall be vertically,
i.e., along the positive Z Axis of the co-ordinate system of the
containing spatial structure element.</li>
</ul>

<p>Figure 60 shows an extrusion of an arbitrary profile definition with voids into the swept area solid of <i>IfcSpace</i>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=
""figures/IfcSpace_Standard-Layout1.gif"" alt=""fig1"" border=""0""
height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 60 &mdash; Space body swept solid</p></td></tr>
</table>

<p><b>'Clipping' representation</b></p>
<p>The advanced geometric representation of <i>IfcSpace</i> is
defined using the swept area solid geometry that can be subjected
to a Boolean expression. The following attribute values should be
inserted.</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Clipping'.</li>
</ul>
<p>The following additional constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see standard geometric representation,</li>
<li><u>Profile</u>: see standard geometric representation,</li>
<li><u>Extrusion</u>: see standard geometric representation,</li>
<li><u>Boolean result</u>: The difference operation with the second
operand being of type <i>IfcHalfSpaceSolid</i> (or one of its
subtypes) shall be supported.</li>
</ul>

<p>Figure 61 shows an extrusion of an arbitrary profile definition into the swept area solid. The solid and an half space solid are operands of the Boolean result of <i>IfcSpace</i>.</font></td>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcSpace_Advanced-Layout1.gif"" alt=""fig2"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 61 &mdash; Space body clipping</p></td></tr>
</table>

<p><b>'Brep' representation</b></p>
<p>The fallback advanced geometric representation of
<i>IfcSpace</i> is defined using the Brep solid geometry.&nbsp;may
be represented as a single or multiple instances of
<i>IfcFacetedBrep</i> or <i>IfcFacetedBrepWithVoids</i>. The Brep
representation allows for the representation of complex element
shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>IfcShapeRepresentation.</i><i>RepresentationIdentifier</i> :
'Body'</li>
<li><i>IfcShapeRepresentation.</i><i>RepresentationType</i> :
'Brep'</li>
</ul>
</EPM-HTML>"
501;IfcSpatialStructureElement;"<EPM-HTML> 
<p>A spatial structure element
(<i>IfcSpatialStructureElement</i>) is the generalization of all
spatial elements that might be used to define a spatial
structure. That spatial structure is often used to provide a
project structure to organize a building project.</p>
<p>A spatial project structure might define as many levels of
decomposition as necessary for the building project. Elements
within the spatial project structure are:</p>
<ul>
<li>site as <i>IfcSite</i></li>
<li>building as <i>IfcBuilding</i></li>
<li>storey as <i>IfcBuildingStorey</i></li>
<li>space as <i>IfcSpace</i></li>
</ul>
<p>or aggregations or parts thereof. The composition type
declares an element to be either an element itself, or an
aggregation (complex) or a decomposition (part). The
interpretation of these types is given at each subtype of
<i>IfcSpatialStructureElement</i>.</p>
<p>The <i>IfcRelAggregates</i> is defined as an 1-to-many
relationship and used to establish the relationship between
exactly two levels within the spatial project structure. Finally
the highest level of the spatial structure is assigned to
<i>IfcProject</i> using the <i>IfcRelAggregates</i>.</p>
<p><u>Informal proposition</u>:</p>
<ol>
<li>The spatial project structure, established by the
<i>IfcRelAggregates</i>, shall be acyclic.</li>
<li>A site should not be (directly or indirectly) associated to a
building, storey or space.</li>
<li>A building should not be (directly or indirectly) associated
to a storey or space.</li>
<li>A storey should not be (directly or indirectly) associated to
a space.</li>
</ol>
<blockquote class=""history"">HISTORY New entity in IFC Release 2x.</blockquote>

<p class=""use-head"">Relationship Use Definition</p>
<p>The subtypes of <i>IfcSpatialStructureElement</i> relate to
other elements and systems by establishing the following
relationships:</p>
<ul>
<li><b>Containment of elements</b> :
<i>IfcRelContainedInSpatialStructure</i> by inverse attribute
<i>ContainsElements</i>, used to assign any element, like
building elements, MEP elements, etc. to the spatial structure
element in which they are primarily contained.
<ul>
<li style=""list-style-type=none""><small>NOTE This relationship is
mandatory for elements in several view definitions and
implementer agreements.</small></li>
</ul>
</li>
<li><b>Reference of elements</b> :
<i>IfcRelReferencedInSpatialStructure</i> by inverse attribute
<i>ReferencesElements</i>, used to reference any element, like
building elements, MEP elements, etc. in spatial structure
elements, other then the one, where it is contained.</li>
<li><b>Reference of systems</b> : <i>IfcRelServicesBuildings</i>
by inverse attribute <i>ServicedBySystems</i>, used to reference
a sytem, like a building service or electrical distribution
system, a zonal system, or a structural analysis system, that is
assigned to this spatial structure element.
<ul>
<li style=""list-style-type=none""><small>NOTE Elements within the
referenced system may be directly contained (or referenced) by
other spatial structure elements.</small></li>
</ul>
</li>
</ul>
<p>The subtypes of <i>IfcSpatialStructureElement</i> relate to
each other by using the <i>IfcRelAggregates</i> relationship to
build the project spatial structure.</p>

<p>Figure 62 shows the use of <i>IfcRelAggregates</i> to establish a spatial structure including site, building, building section and storey. More information is provided at the level of the subtypes.</p>

<table cellpadding=""2"" cellspacing=""2"" summary=""spatial structure"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=
""figures/IfcSpatialStructureElement-SpatialStructure.png"" alt=""fig1"" border=""0"" height=""701"" width=""551""></td></tr>
<tr><td><p class=""figure"">Figure 62 &mdash; Spatial structure element composition</p></td></tr>
</table>

</EPM-HTML>"
509;IfcSpatialElement;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: A spatial element is the
      generalization of all spatial elements that might be used
      to define a spatial structure or to define spatial zones.
    </p>
    <ul>
      <li>a hierarchical spatial structure element as
      <i>IfcSpatialStructureElement</i>
        <ul>
          <li>a spatial structure is a hiearchical decomposition
          of the project. That spatial structure is often used to
          provide a project structure to organize a building
          project.
          </li>
          <li>A spatial project structure might define as many
          levels of decomposition as necessary for the building
          project. Elements within the spatial project structure
          are site, building, storey, and space
          </li>
        </ul>
      </li>
      <li>a spatial zone as <i>IfcSpatialZone</i>
        <ul>
          <li>a spatial zone is a non-hierarchical and
          potentially overlapping decomposition of the project
          under some functional consideration.
          </li>
          <li>a spatial zone might be used to represent a thermal
          zone, a lighting zone, a usable area zone.
          </li>
          <li>a spatial zone might have its independent placement
          and shape representation.
          </li>
        </ul>
      </li>
    </ul>
    <blockquote>
      <small><font color=""#0000FF"">HISTORY New entity in IFC
      Release 2x Edition 4.</font></small>
    </blockquote>
</EPM-HTML>"
516;IfcElement;"<EPM-HTML> 
<p><u>Definition from IAI</u>: Generalization of all components
that make up an AEC product. Those elements can be logically
contained by a spatial structure element that constitutes a
certain level within a project structure hierarchy (e.g., site,
building, storey or space). This is done by using the
<i>IfcRelContainedInSpatialStructure</i> relationship.</p>
<p>Elements are physically existent objects, although they might
be void elements, such as holes. Elements either remain
permanently in the AEC product, or only temporarily, as formwork
does. Elements can be either assembled on site or
pre-manufactured and built in on site.</p>
<blockquote><small>EXAMPLEs of elements in a building
construction context are walls, floors, windows and
recesses.</small></blockquote>
<p>An element can have material and quantity information assigned
through the <i>IfcRelAssociatesMaterial</i> and
<i>IfcRelDefinesByProperties</i> relationship.</p>
<p>In addition an element can be declared to be a specific
occurrence of an element type (and thereby be defined by the
element type properties) using the <i>IfcRelDefinesByType</i>
relationship.</p>
<p>An element can also be defined as an element assembly that is
a group of semantically and topologically related elements that
form a higher level part of the AEC product. Those element
assemblies are defined by virtue of the <i>IfcRelAggregates</i>
relationship.</p>
<blockquote><font size=""-1"">EXAMPLEs for element assembly are
complete Roof Structures, made by several Roof Areas, or a Stair,
composed by Flights and Landings.</font></blockquote>
<p>Elements that performs the same function may be grouped by an
""Element Group By Function"". It is realized by an instance of
<i>IfcGroup</i> with the <i>ObjectType</i> =
'ElementGroupByFunction"".</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 1.0</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcElement</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcElement</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual quantities is introduced at the level of subtypes of
<i>IfcElement</i>.</p>
<p><u><b>Geometry Use Definitions</b></u></p>
<p>The geometric representation of any <i>IfcElement</i> is given
by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations. A detailed specification for the local placement
and shape representaion is introduced at the level of subtypes of
<i>IfcElement</i>.</p>
</EPM-HTML>"
537;IfcBuildingElement;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Major functional part
of a building, examples are foundation, floor, roof, wall.</p>
<p>The building element comprises all
elements that are primarily part of the construction of a
building, i.e., its structural and space separating system.</p>
<blockquote><small>EXAMPLEs of building elements are walls,
beams, or doors, they are all physically existent and tangible
things.</small></blockquote>
<p>The <i>IfcBuildingElement</i> utilizes the following
capabilities mainly through inverse attributes referencing
objectified relationships:</p>
<blockquote><small>NOTE View definitions and implementer
agreements will determine those relationships that have to be
supported in actual exchange.</small></blockquote>
<ol>
<li>Grouping - being part of a logical group of objects
<ul>
<li>objectified relationship: <i>IfcRelAssignsToGroup</i></li>
<li>object referenced by relationship: <i>IfcGroup</i> (and
subtypes)</li>
<li>inverse attribute: <i>HasAssignment</i></li>
</ul>
</li>
<li>Work processes - reference to work tasks, in which this
building element is used
<ul>
<li>objectified relationship: <i>IfcRelAssignsToProcess</i></li>
<li>object referenced by relationship: <i>IfcProcess</i> (and
subtypes)</li>
<li>inverse attribute: <i>HasAssignments</i></li>
</ul>
</li>
<li>Structural member reference - information whether the
building element is represented in a structural analysis model by
a structural member
<ul>
<li>objectified relationship: <i>IfcRelAssignsToProduct</i></li>
<li>object referenced by relationship: <i>IfcStructuralMember</i>
(and by default <i>IfcStructuralCurveMember</i>)</li>
<li>inverse attribute: <i>HasAssignments</i></li>
</ul>
</li>
<li>Aggregation - aggregated together with other elements to form
an aggregate
<ul>
<li>objectified relationship: <i>IfcRelAggregates</i></li>
<li>object referenced by relationship: <i>IfcElement</i> (and
subtypes)</li>
<li>inverse attribute (for container): <i>IsDecomposedBy</i></li>
<li>inverse attribute (for contained parts):
<i>Decomposes</i></li>
</ul>
</li>
<li>Material - assignment of material used by this building
element
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesMaterial</i></li>
<li>object referenced by relationship: <i>IfcMaterialSelect</i>
(and selected items)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Classification - assigned reference to an external
classification
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesClassification</i></li>
<li>object referenced by relationship:
<i>IfcClassificationNotationSelect</i> (and selected items,
default <i>IfcClassificationReference</i>)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Library - assigned reference to an external library item
reference
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesClassification</i></li>
<li>object referenced by relationship: <i>IfcLibrarySelect</i>
(and selected items, default <i>IfcLibraryReference</i>)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Documentation - assigned reference to an external
documentation
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesDocumentation</i></li>
<li>object referenced by relationship: <i>IfcDocumentSelect</i>
(and selected items, default <i>IfcDocumentReference</i>)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Type - reference to the common product type information for
the element occurrence
<ul>
<li>objectified relationship: <i>IfcRelDefinesByType</i></li>
<li>object referenced by relationship:
<i>IfcBuildingElementType</i> (and subtypes)</li>
<li>inverse attribute: <font color=
""#0000FF""><i>IsTypedBy</i></font></li>
</ul>
</li>
<li>Properties - reference to all attached properties, including
quantities
<ul>
<li>objectified relationship:
<i>IfcRelDefinesByProperties</i></li>
<li>object referenced by relationship:
<i>IfcPropertySetDefinition</i> (default
<i>IfcPropertySet</i>)</li>
<li>inverse attribute: <i>IsDefinedBy</i></li>
</ul>
</li>
<li>Connection - connectivity to other elements, including the
definition of the joint
<ul>
<li>objectified relationship: <i>IfcRelConnectsElements</i></li>
<li>object referenced by relationship: <i>IfcElement</i></li>
<li>inverse attribute: <i>ConnectedTo</i></li>
<li>inverse attribute: <i>ConnectedFrom</i></li>
</ul>
</li>
<li>Realization - information, whether the building element is
used to realize a connection (e.g. as a weld in a connection
between two members)
<ul>
<li>objectified relationship:
<i>IfcRelConnectsWithRealizingElements</i></li>
<li>object referenced by relationship: <i>IfcElement</i></li>
<li>inverse attribute: <i>IsConnectionRealization</i></li>
</ul>
</li>
<li>Assignment to spatial structure - hierarchical assignment to
the right level within the spatial structure
<ul>
<li>objectified relationship:
<i>IfcRelContainedInSpatialStructure</i></li>
<li>object referenced by relationship:
<i>IfcSpatialStructureElement</i></li>
<li>inverse attribute: <i>ContainedInStructure</i></li>
</ul>
</li>
<li>Reference to spatial structure(s) - non hierarchical
reference to one or more elements within the spatial structure
(e.g. a curtain wall, being contained in the building, references
several stories)
<ul>
<li>objectified relationship:
<i>IfcRelContainedInSpatialStructure</i></li>
<li>object referenced by relationship:
<i>IfcSpatialElement</i></li>
<li>inverse attribute: <i>ContainedInStructure</i></li>
</ul>
</li>
<li>Boundary - provision of space boundaries by this building
element
<ul>
<li>objectified relationship: <i>IfcRelSpaceBoundary</i></li>
<li>object referenced by relationship: <i>IfcSpace</i></li>
<li>inverse attribute: <i>ProvidesBoundaries</i></li>
</ul>
</li>
<li>Coverings - assignment of covering elements to this building
element (note: normally covering elements are assigned to the
space, only used for special cases)
<ul>
<li>objectified relationship:
<i>IfcRelCoversBldgElements</i></li>
<li>object referenced by relationship: <i>IfcCovering</i></li>
<li>inverse attribute: <i>HasCoverings</i></li>
</ul>
</li>
<li>Voids - information, whether the building element includes
openings, recesses or other voids
<ul>
<li>objectified relationship: <i>IfcRelVoidsElement</i></li>
<li>object referenced by relationship:
<i>IfcFeatureElementSubtraction</i> (default
<i>IfcOpeningElement</i>)</li>
<li>inverse attribute: <i>HasOpenings</i></li>
</ul>
</li>
<li>Projection - information, whether the building element has
projections (such as a fascia)
<ul>
<li>objectified relationship: <i>IfcRelProjectsElement</i></li>
<li>object referenced by relationship:
<i>IfcFeatureElementAddition</i> (default
<i>IfcProjectionElement</i>)</li>
<li>inverse attribute: <i>HasProjections</i></li>
</ul>
</li>
<li>Filling - information whether the building element is used to
fill openings
<ul>
<li>objectified relationship: <i>IfcRelFillsElement</i></li>
<li>object referenced by relationship:
<i>IfcOpeningElement</i></li>
<li>inverse attribute: <i>FillsVoids</i></li>
</ul>
</li>
</ol>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0</blockquote>

<p class=""use-head"">Property Set Use Definition</p>
<p>The properties relating to the <i>IfcBuildingElement</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual property sets applicable is introduced at the level of
subtypes of <i>IfcBuildingElement</i>.</p>
<blockquote><small>NOTE The applicable property sets are provided
by an xml property set definition that includes multilingual
translations for each property. The xml definition file format,
psdXML, can be used to automatically configure the properties for
each building element.</small></blockquote>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcBuildingElement</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual quantities is introduced at the level of subtypes of
<i>IfcBuildingElement</i>.</p>
<blockquote><small>NOTE The applicable element quantities are
provided by an xml quantity definition that includes multilingual
translations for each quantity. The xml definition file format,
qdXML, can be used to automatically configure the quantities for
each building element.</small></blockquote>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The geometric representation of any <i>IfcBuildingElement</i>
is given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for any <i>IfcBuildingElement</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.
Further constraints are defined at the level of its subtypes.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>An <i>IfcBuildingElement</i> can be represented by one or
several geometric representations. The following representation
identifiers are used for building elements 'Box', 'Axis',
'FootPrint', 'Surface', and 'Body'. A detailed specification is
introduced at the level of subtypes.</p>
<blockquote><small>NOTE Some subtypes of
<i>IfcBuildingElement</i> may exclude one or several geometric
representation types, e.g. standard case elements, such as
<i>IfcWallStandardCase</i>, do not allow the use of
'SurfaceModel', 'Brep', 'AdvancedBrep', and
'MappedRepresentation'. In addition view definitions and
implementer agreements may restrict the use of geometric
representation types, e.g. the use of
'AdvancedBrep'.</small></blockquote>
<p><b>Box Representation</b></p>
<p>Any <i>IfcBuildingElement</i> may be represented as a bounding
box, which shows the maximum extend of the body within the
coordinated system established by the <i>IfcLocalPlacement</i>.
The bounding box representation is the simplest geometric
representation available. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Box'</li>
<li><i>RepresentationType</i> : 'BoundingBox'</li>
</ul>

<p>As shown in Figure 22, the bounding box representation is given by an
<i>IfcShapeRepresentation</i> that includes a single item, an
<i>IfcBoundingBox</i>.</p>

<table>
<tbody>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcBuildingElement-BoundingBox-Layout1.gif"" alt=
""bounding box"" border=""0"" height=""275"" width=""400""></td>
<td align=""left"" valign=""top"">
</td></tr>
<tr><td><p class=""figure"">Figure 22 &mdash; Building element box representation</p></td></tr>
</tbody>
</table>

<p><b>Axis Representation</b></p>
<p>Some <i>IfcBuildingElement</i> may be represented by an axis
as an abstract geometric representation. See each subtype for
specific guidance. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation are used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', 'Curve3D'</li>
</ul>
<p><b>Surface Representation</b></p>
<p>Some <i>IfcBuildingElement</i> may be represented by an
surface as an abstract geometric representation. See each subtype
for specific guidance. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation are used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface2D', 'Surface3D'</li>
</ul>
<p><b>FootPrint Representation</b></p>
<p>Any <i>IfcBuildingElement</i> may be represented by a
footprint as a specific floor plan geometric representation. See
each subtype for specific guidance. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation are used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet',
'Annotation2D'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of any <i>IfcBuildingElement</i> can
have the following representation types: 'SurfaceModel', 'Brep',
'AdvancedBrep', and 'MappedRepresentation'. Other representation
types might be specified at the level of subtypes.</p>
<p><i>SurfaceModel Representation Type</i></p>
<p>Any <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple surface models, based on either shell or face
based models. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>

<p>As shown in Figure 23, the surface model representation is given by an <i>IfcShapeRepresentation</i>, which includes a single item which is either:</p>
<ul>
<li><i>IfcShellBasedSurfaceModel</i>, or</li>
<li><i>IfcFaceBasedSurfaceModel</i>.</li>
</ul>
<table>
<tbody>
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBuildingElement-SurfaceModel-Layout1.gif"" alt=""bounding box"" border=""0"" height=""275"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 23 &mdash; Building element surface model representation</p></td></tr>
</tbody>
</table>

<p><i>Brep Representation Type</i></p>
<p>Any <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). The Brep
representation allows for the representation of complex element
shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
<p>As shown in Figure 24, the Brep representation is given by an <small>IfcShapeRepresentation</small>, which includes one or more items, all of type <i>IfcFacetedBrep</i>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBuildingElement-BRep-Layout1.gif"" alt=""Brep representation"" border=""0"" height=""275"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 24 &mdash; Building element body boundary representation</p></td></tr>
</tbody>
</table>

<p><i>AdvancedBrep Representation Type</i></p>
<p>An <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes or by view definitions)
may be represented as a single or multiple Boundary
Representation elements (which are based on advanced surfaces,
usually refered to as NURBS surfaces). The AdvancedBrep
representation allows for the representation of complex free-form
element shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedBrep'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
<p><i>MappedRepresentation Representation Type</i></p>
<p>Any <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented
using the MappedRepresentation. This shall be supported as it
allows for reusing the geometry definition of a type at all
occurrences of the same type. The following attribute values for
the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for 'SurfaceModel', 'Brep', and
'AdvancedBrep' geometric representation, shall apply to the
<i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
</EPM-HTML>"
540;IfcFurnishingElement;"<EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all furniture
related objects. Furnishing objects are characterized as
being</p>
<ul>
<li>pre-manufactured and assembled on-site, or</li>
<li>manufactured on-site (built-in)</li>
</ul>
<p>Thus furnishing elements can either be movable, or not (as the
built-ins).</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 2x.</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcFurnishingElement</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcFurnishingElement</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Any <i>IfcFurnishingElement</i> can be represented by one or
several geometric representations. This includes the general
representation types 'BoundingBox', 'GeometricCurveSet',
'SurfaceModel', 'Brep', and 'MappedRepresentation' being defined
here.</p>
<p><b>Bounding Box Representation</b></p>
<p>Any <i>IfcFurnishingElement</i> may be represented as a
bounding box, which shows the maximum extend of the body within
the coordinated system established by the
<i>IfcLocalPlacement</i>. The bounding box representation is the
simplest geometric representation available. The following
attribute values for the <i>IfcShapeRepresentation</i> holding
this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Box'</li>
<li><i>RepresentationType</i> : 'BoundingBox'</li>
</ul>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcFurnishingElement</i>
is given by either a single or multiple 2D points and curves. The
representation identifier and type of this geometric
representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p><b>SurfaceModel Representation</b></p>
<p>Any <i>IfcFurnishingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple surface models, based on either shell or face
based models. In some cases it may be useful to also expose a
simple representation as a bounding box representation of the
same complex shape. The representation identifier and type of
this geometric representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'SurfaceModel'</li>
</ul>
<p><b>Brep Representation</b></p>
<p>Any <i>IfcFurnishingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). The Brep
representation allows for the representation of complex element
shape. In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape. The representation identifier and type of this
geometric representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Brep'</li>
</ul>
<p><b>MappedRepresentation</b></p>
<p>The <i>IfcMappedItem</i> should always be used in appropriate
cases as it allows for reusing the geometry definition of the
furnishing type for all occurrences of the same type. The
representation identifier and type of this geometric
representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint', or 'Body' (depending of the representation map)</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'MappedRepresentation'</li>
</ul>

</EPM-HTML>"
541;IfcDistributionElement;"<EPM-HTML> 
<p><u>Definition from IAI</u>: Generalization of all elements
that participate in a distribution system. Typical examples of
<i>IfcDistributionElement</i> are (among others):</p>
<ul>
<li>building service elements within a heating systems</li>
<li>building service elements within a cooling system</li>
<li>building service elements within a ventilation system</li>
<li>building service elements within a plumbing system
<ul>
<li>e.g. sanitary elements, fire suppression elements</li>
</ul>
</li>
<li>electrical elements</li>
<li>elements within a communication network</li>
</ul>
<p>The <i>IfcDistributionElement</i> is further specialized in
the IFC model. Direct instantiation of
<i>IfcDistributionElement</i> without an assigned subtype of
<i>IfcDistributionElementType</i> provides the meaning of an
distribution element proxy.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 1.5.</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
<p><b><u>Relationship Use Definition</u></b></p>
<ol>
<li>Ports - information, whether the distribution element has
ports for system connections
<ul>
<li>objectified relationship:
<i>IfcRelConnectsPortToElement</i></li>
<li>object referenced by relationship: <i>IfcPort</i></li>
<li>inverse attribute: <i>HasPorts</i></li>
</ul>
</li>
</ol>
<p><b><u>Type Use Definition</u></b></p>
<p>The <i>IfcDistributionElement</i> defines the occurrence of
any HVAC, electrical, sanitary or other element within a
distribution system. Common information about distribution
element types (or styles) is handled by subtypes of
<i>IfcDistributionElementType</i>. The
<i>IfcDistributionElementType</i> (if present) may establish the
common type name, usage (or predefined) type, common material,
common set of properties and common shape representations (using
<i>IfcRepresentationMap</i>). The
<i>IfcDistributionElementType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p>The assignment of types to distribution element occurrences is
vital for providing the additional meaning, or ontology, of the
distribution element. Many specialized type are defined in other
schemas of the IFC specification.</p>
<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to the <i>IfcDistributionElement</i>
are defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual quantities is introduced at the level of subtypes of
<i>IfcDistributionElement</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcDistributionElement</i> may participate in two
different containment relationships. The first (and in most
implementation scenarios mandatory) relationship is the
hierachical spatial containment, the second (optional)
relationship is the aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcDistributionElement</i> is places within the
project spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcSpace</i> being the default
container.</li>
<li>The <i>IfcDistributionElement</i> may be aggregated into an
element assembly using the objectified relationship
<i>IfcRelAggregates</i>, referring to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcDistributionElement</i>
is given by the <i>IfcProductDefinitionShape</i>, allowing
multiple geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcDistributionElement</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>Geometric Representations</b></p>
<p>The geometric representation of <i>IfcDistributionElement</i>
is defined using different geometric representation types for the
various subtypes. Only general recommendations are given at the
level of the supertype, further constraints are defined at the
level of its subtypes.</p>
<ul>
<li>all occurrences of <i>IfcDistributionElement</i> (and its
subtypes) should (whenever possible) share a representation map
established by the assigned type. The geometric representation of
the occurrence is then an <i>IfcMappedItem</i>. The
<i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
</li>
</ul>
<p>The shared geometric representation of the distribution
element type (or in some cases of the distribution element)
should follow (if applicable) the the following guidelines:</p>
<ul>
<li>all fixtures (all non distribution flow elements, i.e.
everything which is not a duct, a pipe, a cable, or a cable
carrier) should be defined by an b-rep geometry. This includes
also the complex flow fitting elements (e.g. Y branch or T
branch) or distribution flow elements with size changes (e.g.
reducer). The <i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'<br>
<br></li>
</ul>
</li>
<li>if the geometric model consistency of a b-rep shape
representation can not be guaranteed (arcwise connected volume
bounded by faces, each being connected, oriented, finite, closed
2-manifold), a surface representation based on open shells should
be used. The <i>IfcShapeRepresentation</i> then has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel'<br>
<br></li>
</ul>
</li>
<li>all ""simple"" distribution flow elements (general ducts and
pipes) are defined by sweep geometry. The
<i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'<br>
<br></li>
</ul>
</li>
<li>an additional representation type for all ""simple""
distribution flow elements (general ducts and pipes) is the
ability to have a simple line based representation. The
<i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet'<br>
<br></li>
</ul>
</li>
<li>if only the analytical shape is required for which the exact
interpolation between the cross sections is not required, a
sectioned spine can be used.
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SectionedSpine'<br></li>
</ul>
</li>
</ul>
</EPM-HTML>"
545;IfcDistributionElementType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The
<i>IfcDistributionElementType</i> defines a list of commonly
shared property set definitions of an element and an optional set
of product representations. It is used to define an element
specification (i.e. the specific product information, that is
common to all occurrences of that product type).</p>
<blockquote><small>NOTE˙ The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>A distribution element type is used to define the common
properties of a certain type of a distribution element that may
be applied to many instances of that feature type to assign a
specific style. Distribution element types (or the instantiable
subtypes) may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcDistributionElementType</i> are
represented by instances of <i>IfcDistributionElement</i> (or its
subtypes).</p>
<blockquote><small><font color=""#0000FF"">HISTORY˙ New entity in
Release IFC2x Edition 2.</font><br>
<font color=""#FF0000"">IFC2x3 CHANGE˙ The entity has been made
non-abstract</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
</EPM-HTML>"
549;IfcElementType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The <i>IfcElementType</i>
      defines a list of commonly shared property set definitions
      of an element and an optional set of product
      representations. It is used to define an element
      specification (i.e. the specific product information, that
      is common to all occurrences of that product type).
    </p>
    <blockquote>
      <p>
        <small>NOTE The product representations are defined as
        representation maps (at the level of the supertype
        <i>IfcTypeProduct</i>, which gets assigned by an element
        instance through the
        <i>IfcShapeRepresentation.Item[1]</i> being an
        <i>IfcMappedItem</i>.</small>
      </p>
    </blockquote>
    <p>
      An element type is used to define the common properties of
      a certain type or style of an element that may be applied
      to instances of that element type to assign a specific
      style. Element types (the instantiable subtypes) may be
      exchanged without being already assigned to occurrences.
    </p>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in
        Release IFC2x Edition 2</font></small>
      </p>
    </blockquote>
</EPM-HTML>"
557;IfcSpatialElementType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcSpatialElementType</i>
defines a list of commonly shared property set definitions of a
spatial structure element and an optional set of product
representations. It is used to define a spatial element
specification (i.e. the specific element information, that is
common to all occurrences of that element type).</p>
<blockquote>
<p><small>NOTE ˙The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></p>
</blockquote>
<p>A spatial element type is used to define the common properties
of a certain type of a spatial structure element that may be
applied to many instances of that˙type to assign a specific
style. Spatial element types (i.e. the instantiable subtypes) may
be exchanged without being already assigned to occurrences.</p>
<blockquote>
<p><small>NOTE ˙The spatial element types are often used to
represent catalogues of predefined spatial types for shared
attributes, less so for sharing a common representation
map.</small></p>
</blockquote>
<p>The occurrences of subtypes of the abstract
<i>IfcSpatialElementType</i> are represented by instances of
subtypes of the abstract <i>IfcSpatialElement</i>.</p>
<blockquote>
<p><small><font color=""#0000FF"">HISTORY ˙New entity in Release
IFC2x Edition 4.</font></small></p>
</blockquote>
</EPM-HTML>"
561;IfcSpatialStructureElementType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The element type
      (<i>IfcSpatialStructureElementType</i>) defines a list of
      commonly shared property set definitions of a spatial
      structure element and an optional set of product
      representations. It is used to define an element
      specification (i.e. the specific element information, that
      is common to all occurrences of that element type).
    </p>
    <blockquote>
      <p>
        <small>NOTE ˙The product representations are defined as
        representation maps (at the level of the supertype
        <i>IfcTypeProduct</i>, which gets assigned by an element
        occurrence instance through the
        <i>IfcShapeRepresentation.Item[1]</i> being an
        <i>IfcMappedItem</i>.</small>
      </p>
    </blockquote>
    <p>
      A spatial structure element type is used to define the
      common properties of a certain type of a spatial structure
      element that may be applied to many instances of that˙type
      to assign a specific style. Spatial structure element types
      (i.e. the instantiable subtypes) may be exchanged without
      being already assigned to occurrences.
    </p>
    <blockquote>
      <p>
        <small>NOTE ˙The spatial structure element types are
        often used to represent catalogues of predefined spatial
        types for shared attributes, less so for sharing a common
        representation map.</small>
      </p>
    </blockquote>
    <p>
      The occurrences of subtypes of the
      abstract˙<i>IfcSpatialStructureElementType</i> are
      represented by instances of subtypes of
      <i>IfcSpatialStructureElement</i>.
    </p>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY ˙New entity in
        Release IFC2x Edition 3.</font></small>
      </p>
    </blockquote>
</EPM-HTML>"
563;IfcSpaceType;"<EPM-HTML>
<p><u>Definition from IAI</u>: A space represents an area or
volume bounded actually or theoretically. Spaces are areas or
volumes that provide for certain functions within a building.</p>
<p>The <i>IfcSpaceType</i> defines a list of commonly shared
defines commonly shared information for occurrences of spaces.
The set of shared information may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common shape representations</li>
</ul>
<p>It is used to define an space specification (i.e. the specific
space information, that is common to all occurrences of that
space type. Space types may be exchanged without being already
assigned to occurrences.</p>
<blockquote><small>NOTE ˙The space types are often used to
represent space catalogues, less so for sharing a common
representation map. Space types in a space catalogue share same
space classification and a common set of space requirement
properties.</small></blockquote>
<p>The occurrences of <i>IfcSpaceType</i> are represented by
instances of <i>IfcSpace</i>.</p>
<blockquote>
<p><small><font color=""#0000FF"">HISTORY ˙New entity in
IFC2x3.</font></small></p>
</blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcSpaceType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcSpaceType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcSpaceType</i> and those that are only assignable to
<i>IfcSpace</i>. If the same property is assigned to the
<i>IfcSpaceType</i> and the <i>IfcSpace</i> being an occurrence
of the <i>IfcSpaceType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href=""../../psd/IfcProductExtension/Pset_SpaceCommon.xml""
target=""SOURCE"">Pset_SpaceCommon</a>: common property set for all
types of spaces
<ul>
<li><a href=""../../psd/IfcProductExtension/Pset_SpaceParking.xml""
target=""SOURCE"">Pset_SpaceParking</a>: specific property set for
only those spaces that are used to define parking spaces by
<i>PredefinedType</i>: PARKING</li>
</ul>
</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceFireSafetyRequirements.xml""
target=""SOURCE"">Pset_SpaceFireSafetyRequirements</a>: common
property set for all types of spaces to capture the fire safety
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceLightingRequirements.xml""
target=""SOURCE"">Pset_SpaceLightingRequirements</a>: common
property set for all types of spaces to capture the lighting
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceOccupancyRequirements.xml""
target=""SOURCE"">Pset_SpaceOccupancyRequirements</a>: common
property set for all types of spaces to capture the occupancy
requirements</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_SpaceThermalRequirements.xml""
target=""SOURCE"">Pset_SpaceThermalRequirements</a>: common
property set for all types of spaces to capture the thermal
requirements</li>
<li><a href=
""../../psd/IfcSharedBldgServiceElements/Pset_SpaceThermalDesign.xml""
target=""SOURCE"">Pset_SpaceThermalDesign</a>: common property set
for all˙all types of spaces to capture building service design
values</li>
</ul>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcSpaceType</i> may define the shared geometric
representation for all space occurrences. The
<i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an RepresentationIdentifier 'Box', 'FootPrint', or 'Body').</p>
<blockquote>
<p><small>NOTE ˙The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></p>
</blockquote>
<blockquote><small>However view definitions and implementer
agreements may prevent the usage of shared geometry for
spaces.</small></blockquote>
.
</EPM-HTML>"
574;IfcSpatialZoneType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcSpatialZoneType</i>
defines a list of commonly shared property set definitions of a
space and an optional set of product representations. It is used
to define a space specification (i.e. the specific space
information, that is common to all occurrences of that space
type).</p>
<blockquote>
<p><small>NOTE ˙The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></p>
</blockquote>
<p>A spatial zone type is used to define the common properties of
a certain type of space that may be applied to many instances of
that type to assign a specific style. Space types may be
exchanged without being already assigned to occurrences.</p>
<blockquote>
<p><small>NOTE ˙The spatial zone types are often used to
represent space catalogues, less so for sharing a common
representation map. Spatial zone types in a space catalogue share
same space classification and a common set of space requirement
properties.</small></p>
</blockquote>
<p>The occurrences of <i>IfcSpatialZoneType</i> are represented
by instances of <i>IfcSpatialZone</i>.</p>
<blockquote>
<p><small><font color=""#0000ff"">HISTORY ˙New entity in Release
IFC2x Edition 4.</font></small></p>
</blockquote>
</EPM-HTML>"
586;IfcBuildingElementType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The element type
      (<i>IfcBuildingElementType</i>) defines a list of commonly
      shared property set definitions of a building element and
      an optional set of product representations. It is used to
      define an element specification (i.e. the specific product
      information, that is common to all occurrences of that
      product type).
    </p>
    <blockquote>
      <p>
        <font size=""-1"">NOTE: The product representations are
        defined as representation maps (at the level of the
        supertype <i>IfcTypeProduct</i>, which gets assigned by
        an element occurrence instance through the
        <i>IfcShapeRepresentation.Item[1]</i> being an
        <i>IfcMappedItem</i>.</font>
      </p>
    </blockquote>
    <p>
      A building element type is used to define the common
      properties of a certain type of a building element that may
      be applied to many instances of that feature type to assign
      a specific style. Building element types (or the
      instantiable subtypes) may be exchanged without being
      already assigned to occurrences.
    </p>
    <p>
      The <i>IfcBuildingElementType</i> is an abstract type.
      Occurrences of subtypes of the
      <i>IfcBuildingElementType</i> are represented by instances
      of the appropriate subtypes of <i>IfcBuildingElement</i>.
    </p>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY  New entity in
        Release IFC2x Edition 2.</font></small>
      </p>
    </blockquote>
</EPM-HTML>"
587;IfcFurnishingElementType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The
<i>IfcFurnishingElementType</i> defines a list of commonly shared
property set definitions of an element and an optional set of
product representations. It is used to define an element
specification (i.e. the specific product information, that is
common to all occurrences of that product type).</p>
<blockquote><small>NOTE˙ The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>A furnishing element type is used to define the common
properties of a certain type of a furnishing element that may be
applied to many instances of that feature type to assign a
specific style. Furnishing element types (or the instantiable
subtypes) may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcFurnishingElementType</i> are
represented by instances of <i>IfcFurnishingElement</i> (or its
subtypes).</p>
<blockquote><small><font color=""#0000FF"">HISTORY˙New entity in
Release IFC2x Edition 2.</font></small><br>
<small><font color=""#FF0000"">IFC2x3 CHANGE The entity has been
made non-abstract</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
</EPM-HTML>"
590;IfcTransportElementType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcTransportElementType</i> defines commonly shared
information for occurrences of transport elements. The set of
shared information may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common shape representations</li>
</ul>
<p>It is used to define a transport element specification (i.e.
the specific product information that is common to all
occurrences of that beam type). Transport element types (or the
instantiable subtypes) may be exchanged without being already
assigned to occurrences.</p>
<p>The occurrences of the <i>IfcTransportElementType</i> are
represented by instances of <i>IfcTransportElement</i> (or its
subtypes).</p>
<blockquote>
<p><font color=""#0000FF"" size=""-1"">HISTORY: New entity in Release
IFC2x Edition 2.</font></p>
</blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the
<i>IfcTransportElementType</i> are defined by the
<i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcTransportElementType</i> are
part of this IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcTransportElementType</i> and those that are only assignable
to <i>IfcTransportElement</i>. If the same property is assigned
to the <i>IfcTransportElementType</i> and the
<i>IfcTransportElement</i> being an occurrence of the
<i>IfcTransportElementType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_TransportElementCommon.xml""
target=""SOURCE"">Pset_TransportElementCommon</a>: common property
set for all transport element types
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_TransportElementElevator.xml""
target=""SOURCE"">Pset_TransportElementElevator</a>: specific
property set for all types of transport elements with the
<i>PredefinedType</i>: ELEVATOR</li>
</ul>
</li>
</ul>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcTransportElementType</i> may define the shared
geometric representation for all transport element occurrences.
The <i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an <i>RepresentationIdentifier</i> 'Box', 'FootPrint', or
'Body').</p>
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcTransportElementType</i>.</small></blockquote>
</EPM-HTML>"
601;IfcGeographicElementType;"<EPM-HTML> 
    <p>
      <u>Definition from IAI</u>: An
      <i>IfcGeographicElementType</i> is used to define an
      element specification of a geographic element (i.e. the
      specific product information, that is common to all
      occurrences of that product type).˙Geographic element types
      include for different types of element that may be used to
      represent information within a geographical landscape
      external to a building. Within the world of geographic
      information they are referred to generally as 'features'.˙
    </p>Geographic element types includes for many possibilities:
    <ul>
      <li>linear elements such as sections of a roadway
      (including carriageway/pavement, verge, median, marker
      line, kerb etc.), path, river, stream
      </li>
      <li>connections and junctions including traffic
      roundabouts, T junctions, 4 way junctions
      </li>
      <li>point features such as street lighting, seating, bus
      shelters, signage, trees
      </li>
      <li>linear features such as layby's
      </li>
      <li>area features such as ponds, lakes, woods and forests
      </li>
    </ul>
    <p>
      The specification of the specific types are given by the
      inherited attribute <i>IfcElementType.ElementType</i> given
      as an <i>IfcLabel</i>.˙
    </p>
    <blockquote>
      <p>
        <small>NOTE ˙This is due to the range of choices of
        element type thyat are available and their expression in
        different languages. It is not considered possible to
        create a reasonably full list of types within an
        enumeration. It is suggested that selection of the
        relevant type be drawn from an available 'feature
        catalog'.</small>
      </p>
      <p>
        <small><font color=""#0000FF"">HISTORY˙ New entity in
        Release IFC2x Edition 4.</font></small>
      </p>
    </blockquote>
    <p>
      <b><u>Feature Catalog Use Definition</u></b>
    </p>
    <p>
      Geographic element types are frequently identified in
      feature catalogs that are produced for particular
      purposes.˙The <i>IfcGeographicElementType</i> entity
      enables the continued use of existing feature catalogs
      through capture of their identity and attributes.
    </p>
    <p>
      Information from feature catalogs might be captured in
      various ways:
    </p>
    <ol>
      <li>via property sets, some of which will be specifically
      defined within the IFC property set catalog whilst others
      will be created for local use; this is the form of capture
      that is expected to be most widely used
      </li>
      <li>through use of the IFC classification model whereby
      features might be identified through a classification
      notation and additional description; in which case, any
      further attributes required would still need to be captured
      in property sets.
      </li>
    </ol>
</EPM-HTML>"
607;IfcElementAssemblyType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcElementAssemblyType</i>
defines a list of commonly shared property set definitions of an
element and an optional set of product representations. It is
used to define an element specification (i.e. the specific
product information, that is common to all occurrences of that
product type).</p>
<blockquote><small>NOTE˙ The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>An element assembly type is used to define the common
properties of a certain type of an element assembly that may be
applied to many instances of that type to assign a specific
style. An element assembly types (or the instantiable subtypes)
may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcElementAssemblyType</i> are
represented by instances of <i>IfcElementAssembly</i>.</p>
<blockquote><small><font color=""#0000FF"">HISTORY˙ New entity in
Release IFC2x Edition 4.</font></small></blockquote>
</EPM-HTML>"
622;IfcRelConnectsPortToElement;"<EPM-HTML>
<p>The objectified relationship
<em>IfcRelConnectsPortToElement</em> defines the relationship that
is made between a port and the <em>IfcElement</em>, or
<em>IfcElementType</em> in which it is contained. It is a 1 to 1
relationship.</p>
<blockquote>
<p><span style=""font-size:smaller"">The
<em>IfcRelConnectsPortToElement</em> established a whole part
relationship between the element and its port. The port is used as
the means to connect to other ports in other elements. Since both,
the element-to-port, and the port-to-port relationships are 1:1
relationships, a topological system (or system path or ciruit) can
be defined.</span></p>
</blockquote>
<p>Ports contained in different elements are connected to each
other using the <em>IfcRelConnectsPorts</em> relationship.</p>
<blockquote>
<p><span style=""font-size:smaller"">See relevant subtypes of
<em>IfcDistributionElement</em> for examples and port use
definition sections.</span></p>
</blockquote>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">HISTORY&nbsp; New
entity in Release IFC2x Edition 2.</span><br>
<span style=""font-size:smaller;color:red"">IFC2x4 CHANGE&nbsp; The
definition has been extended to include element types.</span></p>
</blockquote>

</EPM-HTML>"
626;IfcPort;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: An <i>IfcPort</i> provides the
      means for an element to connect to other elements.
    </p>
    <p>
      An <i>IfcPort</i> is associated with an <i>IfcElement</i>,
      it belongs to, through the objectified relationship
      <i>IfcRelConnectsPortToElement</i>. Exactly two ports,
      belonging to two different elements, are connected with
      each other through the objectified relationship
      <i>IfcRelConnectsPorts</i>.
    </p>
    <p>
      An instance of <i>IfcElement</i> may have one or more
      points at which it connects to other instances of
      <i>IfcElement</i>. An instance of <i>IfcPort</i> is located
      at a point where a connection can occur. The location of
      the port is determined in the context of the local
      coordinate system of the element to which it belongs.
    </p>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in
        Release IFC2x Edition 2.</font></small>
      </p>
    </blockquote>
    <p>
      <b><u>Containment Use Definitions</u></b>
    </p>
    <p>
      As a subordinate part being fully dependent on the master
      element the <i>IfcPort</i> shall have no
      independent containment relationship to the spatial
      structure.
    </p>
		    <p>
      <b><u>Geometry Use Definition</u></b>
    </p>
    <p>
      The geometric representation of <i>IfcPort</i> is
      given by the <i>IfcProductDefinitionShape</i>, allowing
      multiple geometric representation.
    </p>
    <p>
      <b>Local Placement</b>
    </p>
    <p>
      The local placement for <i>IfcPort</i> is defined
      in its supertype <i>IfcProduct</i>. It is defined by the
      <i>IfcLocalPlacement</i>, which defines the local
      coordinate system that is referenced by all geometric
      representations.
    </p>
    <ul>
      <li>The <i>PlacementRelTo</i> relationship of
      <i>IfcLocalPlacement</i> shall point to the
      local placement of the master <i>IfcElement</i> (its
      relevant subtypes), which is associated to the
      <i>IfcPort</i> by the relationship object
			<i>IfcRelConnectsPortToElement</i>.
      </li>
    </ul>
		    <p>
      <b>Shape Representation</b>
    </p>
    <p>
      The geometry use definitions for the shape representation
      of the <i>IfcPort</i> is given at the level of
      its subtypes.
    </p>
</EPM-HTML>"
630;IfcRelConnectsPorts;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: An <i>IfcRelConnectsPorts</i>
      defines the relationship that is made between two ports at
      their point of connection. It may include the connection
      geometry between two ports.
    </p>
    <p>
      <i>IfcRelConnectsPorts</i> is required for defining how
      instances of <i>IfcPort</i> connect together. Each of the
      port is being logically attached to the <i>IfcElement</i>
      by using the <i>IfcRelConnectsPortToElement</i>
      relationship.
    </p>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in IFC
        2.0, modified in IFC2x.</font></small>
      </p>
    </blockquote>
</EPM-HTML>"
638;IfcTransportElement;"<EPM-HTML> 
<p><u>Definition from IAI</u>: Generalization of all transport
related objects that move people, animals or goods within a
building or building complex. The <i>IfcTransportElement</i>
defines the occurrence of a transport element, that (if given),
is expressed by the <i>IfcTransportElementType</i>.</p>
<blockquote><small>EXAMPLE Transportation elements include
elevator (lift), escalator, moving walkway, etc.</small><br>
<small>NOTE More detailed equipment that may be a part of a
transportation device, like a lifting hook, is defined as
<i>IfcDiscreteAccessory</i></small></blockquote>
<p>Depending on local classification systems transport elements
and transportation systems in buildings are either considered as
part of a building system, or as part of a building service
system. Within IFC they are considered as part of a building
system and may have to be mapped appropriately.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 2x.</font></small><br>
<font color=""#FF0000""><small>IFC2x PLATFORM CHANGE The attribute
<i>PredefinedType</i> (previously OperationType) is made
optional.</small></font></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcTransportElement</i> defines the occuurence of any
transportation device, common information about transportation
device types (or styles) is handled by
<i>IfcTransportElementType</i>. The
<i>IfcTransportElementType</i> (if present) may establish the
common˙type name, usage (or predefined) type, common material
layer set, common set of properties and common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcTransportElementType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcTransportElementType</i> is attached˙(i.e. if only
occurrence information is given) the <i>PredefinedType</i> should
be provided. If set to .USERDEFINED. a user defined value can be
provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcTransportElement</i>
are defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the
<i>IfcTransportElement</i> are part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_TransportElementCommon.xml""
target=""SOURCE"">Pset_TransportElementCommon</a>: common property
set for all transport element occurrences
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_TransportElementElevator.xml""
target=""SOURCE"">Pset_TransportElementElevator</a>: specific
property set for all occurrences of transport elements with the
<i>PredefinedType</i>: ELEVATOR</li>
</ul>
</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcTransportElement</i>, as any subtype of
<i>IfcElement</i>, may have a hierarchical spatial containment
relationships that is mandatory in most implementation
scenarios.</p>
<ul>
<li>The <i>IfcTransportElement</i> is placed within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuilding</i> being the default
container.</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcTransportElement</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcTransportElement</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>SurfaceModel Representation</b></p>
<p>Any <i>IfcTransportElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple surface models, based on either shell or face
based models. Then the following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel'</li>
</ul>
<p><b>Brep Representation</b></p>
<p>Any <i>IfcTransportElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). Then the
following attribute values for the <i>IfcShapeRepresentation</i>
holding this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
<p><b>MappedRepresentation</b></p>
<p>The mapped item, <i>IfcMappedItem</i>, should be used if
appropriate as it allows for reusing the geometry definition of
the property element type at occurrences of the same equipement
type. Then the following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
</EPM-HTML>"
644;IfcFeatureElement;"<EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all existence
dependent elements which modify the shape and appearance of the
associated master element. The <i>IfcFeatureElement</i> offers
the ability to handle shape modifiers as semantic objects within
the IFC object model.</p>
<blockquote>
<p><small>NOTE The term ""feature"" has a predefined meaning in a
context of ""feature-based modeling"" and within steel construction
work. It is introduced here in a broader sense to cover all
existence dependent, but semantically described, modifiers of an
element's shape and appearance. It is envisioned that future
releases enhance the feature-based capabilities of the IFC
model.</small></p>
</blockquote>
<p>In contrary to the aggregation, as used in
<i>IfcElementAssembly</i>, that defines the aggregate as a
container element, that has equally treated parts, the feature
concept introduced by <i>IfcFeatureElement</i> defines the master
element with subordinate parts as additions, or with voids or
cut-outs as subtractions.</p>
<blockquote>
<p><small><font color=""#0000FF"">HISTORY New entity in Release
IFC2x Edition 2.</font></small><br>
<small><font color=""#FF0000"">NOTE The entity is introduced as an
upward compatible extension of the IFC2x platform. It is an
intermediate abstract supertype without defining its own explicit
attributes.</font></small></p>
</blockquote>
<p><b><u>Containment Use Definition</u></b></p>
<p>As a subordinate part being fully dependent on the master
element the <i>IfcFeatureElement</i> shall have no independent
containment relationship to the spatial structure.</p>
<ul>
<li>The <i>SELF\IfcElement.ContainedInStructure</i> relationship
shall be NIL.</li>
</ul>
<p><b><u>Geometry Use Definition</u></b></p>
<p>The geometric representation of <i>IfcFeatureElement</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcFeatureElement</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the master <i>IfcElement</i> (its relevant
subtypes), which is associated to the <i>IfcFeatureElement</i> by
the appropriate relationship object.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>Geometric Representations</b></p>
<p>Any <i>IfcFeatureElement</i> can be represented by one or
several geometric representations. A detailed specification is
introduced at the level of subtypes. Only the general
representation identifier 'Box' with representation type
'BoundingBox', and representation identifier 'Body' with
representation type 'Brep' are defined here.</p>
<p><b>Box Representation</b></p>
<p>Any <i>IfcFeatureElement</i> may be represented as a bounding
box, which shows the maximum extend of the body within the
coordinated system established by the <i>IfcLocalPlacement</i>.
The bounding box representation is the simplest geometric
representation available. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Box'</li>
<li><i>RepresentationType</i> : 'BoundingBox'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of any <i>IfcFeatureElement</i> can
have the following representation types: 'Brep'. Other
representation types might be specified at the level of
subtypes.</p>
<p><i>Brep Representation Type</i></p>
<p>Any <i>IfcFeatureElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). The Brep
representation allows for the representation of complex element
shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
</EPM-HTML>"
647;IfcFeatureElementAddition;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: A specialization of the general
      feature element, that represents an existence dependent
      element which modifies the shape and appearance of the
      associated master element. The
      <i>IfcFeatureElementAddition</i> offers the ability to
      handle shape modifiers as semantic objects within the IFC
      object model that add to the shape of the master element.
    </p>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in
        Release IFC2x Edition 2.</font></small><br>
        <small><font color=""#FF0000"">NOTE The entity is
        introduced as an upward compatible extension of the IFC2x
        platform. It is an intermediate abstract supertype
        without defining its own explicit
        attributes.</font></small>
      </p>
    </blockquote>
    <p>
      The <i>IfcFeatureElementAddition</i> is associated to its
      master element by virtue of the objectified relationship
      <i>IfcRelProjectsElement</i>. This relationship implies a
      Boolean 'union' operation between the shape of the master
      element and the shape of the addition feature.
    </p>
    <p>
      <b><u>Containment use definition</u></b>
    </p>
    <p>
      The containment to the spatial structure is defined at the
      level of the supertype <i>IfcFeatureElement</i>
    </p>
    <p>
      <b><u>Geometry Use Definitions</u></b>
    </p>
    <p>
      The geometric representation of
      <i>IfcFeatureElementAddition</i> is given by the
      <i>IfcProductDefinitionShape</i>, allowing multiple
      geometric representations.
    </p>
    <p>
      <b>Local Placement</b>
    </p>
    <p>
      The local placement for <i>IfcFeatureElementAddition</i> is
      defined in its supertype <i>IfcProduct</i>. It is defined
      by the <i>IfcLocalPlacement</i>, which defines the local
      coordinate system that is referenced by all geometric
      representations. The local placement is always defined in
      relation to the local placement of the element to which the
      feature element is added:
    </p>
    <ul>
      <li>The <i>PlacementRelTo</i> relationship of
      <i>IfcLocalPlacement</i> shall point to the local placement
      of the same <i>IfcElement</i>, which is used in the
      <i>HasAdditionFeature.RelatingElement</i> inverse
      attribute.
      </li>
    </ul>
    <p>
      <b>Shape Representation</b>
    </p>
    <p>
      The geometry use definitions for the shape representation
      of the <i>IfcFeatureElementAddition</i> is given at the
      level of its subtypes.
    </p>
</EPM-HTML>"
650;IfcProjectionElement;"<EPM-HTML>
<p>The projection element is a
specialization of the general feature element to represent
projections applied to building elements. It represents a solid
attached to any element that has physical manifestation.</p>
<blockquote><small>EXAMPLE A wall projection such as a pilaster
strip is handled by
<i>IfcProjectionElement</i></small></blockquote>
<blockquote><small>NOTE View definitions or implementer agreements
may restrict the types of elements to which
<i>IfcProjectionElement</i> can be applied.</small></blockquote>
<p>An <i>IfcProjectionElement</i> has to be linked to a element
(all subtypes of <i>IfcElement</i>) by using the
<i>IfcRelProjectsElement</i> relationship. Its existence depends on
the existence of the master element. The relationship implies a
Boolean union operation between the volume of the projection
element and the volume of the element.</p>
<blockquote class=""history"">HISTORY New entity in IFC2x2.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE The attribute <i>PredefinedType</i> has been added at the end of attribute
list.</blockquote>
<p>The quantities relating to the <i>IfcProjectionElement</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
""../../qto/IfcProductExtension/Qto_ProjectionElementBaseQuantities.xml""
target=""SOURCE"">Qto_ProjectionElementBaseQuantities</a>: base
quantities for all opening occurrences.</li>
</ul>
<p class=""use-head"">Containment Use Definition</p>
<p>The <i>IfcProjectionElement</i> shall not participate in the
containment relationship, i.e. it is not linked directly to the
spatial structure of the project. It has a mandatory
<i>ProjectsElements</i> inverse relationship pointing to the
<i>IfcElement</i> that is contained in the spatial structure.</p>
<ul>
<li>The inverse relationship <i>ContainedInStructure</i> shall be
NIL.</li>
</ul>
<p class=""use-head"">Geometry Use Definition</p>
<p>The geometric representation of <i>IfcProjectionElement</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcOpeningRecess</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> should point to the local placement of the
same element, to which the projection adds, i.e. referred to by
<i>ProjectsElement.RelatingBuildingElement</i>.</li>
</ul>
<p><b>Swept Solid Representation</b></p>
<p>The geometric representation of <i>IfcProjectionElement</i> is
defined using the swept area solid geometry. The following
attribute values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required.</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and <i>IfcArbitraryClosedProfileDef</i>
shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded horizontally
(that is, perpendicular to the extrusion direction of the modified
element), such as for wall projections, or vertically (that is, in the
extrusion direction of the projected element), such as for floor
projections.</li>
</ul>

<p>As shown in Figure 38, the following interpretation of dimension parameter applies for
rectangular projection:</p>
<ul>
<li><i>IfcRectangleProfileDef.YDim</i> interpreted as projection
width</li>
<li><i>IfcRectangleProfileDef.XDim</i> interpreted as projection
height</li>
<li><i>IfcExtrudedAreaSolid.Depth</i> is interpreted as projection
depth</li>
</ul>
<blockquote class=""note"">NOTE &nbsp;Rectangles are now defined centric, the placement location has to be set:
<ul><li><i>IfcCartesianPoint</i>(XDim/2,YDim/2)</li></ul></blockquote>
<blockquote class=""note"">NOTE &nbsp;The local placement directions for the <i>IfcProjectionElement</i> are only given as an example, other directions are valid as well.</blockquote>

<table cellpadding=""2"" cellspacing=""2"" summary=""geometry use"">
<tr valign=""top""><td valign=""top"" align=""left""><img src=""figures/IfcProjectionElement-Layout1.png"" alt=""projection"" width=
""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 38 &mdash; Projection representation</p></td></tr>
</table>

<p><b>Brep Representation</b></p>
<p>The general b-rep geometric representation of
<i>IfcProjectionElement</i> is defined using the Brep geometry. The
Brep representation allows for the representation of complex
element shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>

</EPM-HTML>"
655;IfcRelProjectsElement;"<EPM-HTML>
<p>The <i>IfcRelProjectsElement</i> is an objectified relationship
between an element and one projection element that creates a
modifier to the shape of the element. The relationship is defined
to be a 1:1 relationship, if an element has more than one
projection, several relationship objects have to be used, each
pointing to a different projection element. The
<i>IfcRelProjectsElement</i> establishes an aggregation
relationship between the main element and a sub ordinary addition
feature.</p>
<blockquote>
<p><span style=""font-size:smaller"">NOTE&nbsp; In contrary the
<em>IfcRelAggregates</em> relationship established an aggregation
of equal parts to a whole.</span></p>
</blockquote>
<p>The <i>IfcRelProjectsElement</i> implies a Boolean operation of
addition for the geometric bodies of the element and the feature
element. As with all decomposition relationships it determines:</p>
<ul>
<li>existence dependency - the <em>RelatedFeatureElement</em>
cannot exist without the <em>RelatingElement</em></li>
<li>hierarchical and non-cyclical relationship - the
<em>IfcRelProjectsElement</em> can only alter a single
<em>IfcElement</em></li>
<li>no spatial containment - the <em>IfcFeatureElementAddition</em>
as related element never participates in the hiearchical spatial
containment relationship
<em>IfcRelContainedInSpatialStructure</em></li>
</ul>
<blockquote>
<p><span style=""font-size:smaller;color=blue"">HISTORY New entity in
Release IFC2x Edition 2.</span><br>
<span style=""font-size:smaller;color=red"">IFC2x4 CHANGE&nbsp;
Supertype changed to IfcRelDecomposes.</span></p>
</blockquote>

</EPM-HTML>"
658;IfcRelVoidsElement;"<EPM-HTML> 

<p><i>IfcRelVoidsElement</i> is an objectified relationship between a building element and one opening element that creates a void in the element. It is a one-to-one relationship. This relationship implies a Boolean operation of subtraction between the geometric bodies of the element and the opening.</p>

<p>As shown in Figure 50, the insertion of a void into a wall is represented by the relationship <i>IfcRelVoidsElement</i>. The opening is created within the wall by <i>IfcWall(StandardCase) o-- IfcRelVoidsElement --o IfcOpeningElement</i>.</p>

<table border=""0"" cellpadding=""0"" cellspacing=""0"" width=""502"" summary=""example for voiding"">
<tr><td><img src=""figures/IfcRelVoidsElements-Fig1.png"" alt=""relationships for voiding"" width=""501"" height=""271"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 50 &mdash; Relationship for element voiding</p></td></tr>
</table>

<blockquote class=""history"">HISTORY New entity in IFC Release 1.0</blockquote>

</EPM-HTML>"
661;IfcFeatureElementSubtraction;"<EPM-HTML>
<p>The <em>IfcFeatureElementSubtraction</em> is specialization of
the general feature element, that represents an existence dependent
elements which modifies the shape and appearance of the associated
master element. The <i>IfcFeatureElementSubtraction</i> offers the
ability to handle shape modifiers as semantic objects within the
IFC object model that subtract from the shape of the master
element.</p>
<blockquote>
<p><span style=""font-size:smaller"">A single subtraction feature
such as the subtype <em>IfcOpeningElement</em> is assigned by a
single subtraction relationship <em>IfcRelVoidsElement</em> to one
occurrences of <em>IfcElement</em>. It establishes a 1:1
relationship between the opening and the element. An element may
have several <em>IfcRelVoidsElement</em> relationships, enabling
several voids.</span></p>
</blockquote>
<p>The voiding relationship between a master element and a
subtraction feature is geometrically resolved by a Boolean
difference operation.</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">HISTORY New entity in
Release IFC2x Edition 2.</span><br></p>
</blockquote>
<p><b><u>Containment use definition</u></b></p>
<p>The <em>IfcFeatureElementSubtraction</em> shall have no
independent containment relationship to the spatial structure. See
explanation at supertype <i><em>IfcFeatureElement</em></i></p>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of
<i>IfcFeatureElementSubtraction</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcFeatureElementSubtraction</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations. The local
placement is always defined in relation to the local placement of
the building element from which the feature element substration is
substracted:</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcElement</i>, which is used in the
<i>VoidsElements.RelatingElement</i> inverse attribute.</li>
</ul>
<p><b>Shape Representation</b></p>
<p>The geometry use definitions for the shape representation of the
<i>IfcFeatureElementSubtraction</i> is given at the level of its
subtypes.</p>

</EPM-HTML>"
666;IfcOpeningElement;"<EPM-HTML> 
<p>The opening element stands for
opening, recess or chase, all reflecting voids. It represents a
void within any element that has physical manifestation. Openings
can be inserted into walls, slabs, beams, columns, or other
elements.</p>
<p>The IFC specification provides two entities for opening
elements:</p>
<ul>
<li><i>IfcOpeningStandardCase</i> is used for all openings that
have a constant profile along a linear extrusion. They are placed
relative to the voided elements and the extrusion direction is
perpendicular to the plane of the element (horizontally for
walls, vertically for slabs). Only a single extrusion body is
allowed. It cuts through the whole thickness of the voided
element, i.e. it reflects a true opening.</li>
<li><i>IfcOpeningElement</i> is used for all other occurrences of
openings and in particular also for niches or recesses.</li>
</ul>
<blockquote><small>NOTE View definitions or implementer
agreements may restrict the types of elements which can be voided
by an <i>IfcOpeningElement</i> or
<i>IfcOpeningStandardCase</i></small></blockquote>
<p>There are two different types of opening elements:</p>
<ul>
<li>an opening, where the thickness of the opening is greater or
equal to the thickness of the element;</li>
<li>a recess or niche, where the thickness of the recess is
smaller than the thickness of the element.</li>
</ul>
<p>The attribute <i>PredefinedType</i> should be used to capture
the differences,</p>
<ul>
<li>the attribute is set to OPENING for an opening or</li>
<li>the attribute is set to RECESS for a recess or niche.</li>
<li>If the value for <i>PredefinedType</i> is omitted, or the
value is set to NOTDEFINED, no specific information of whether it
is an opening or recess shall be assumed.</li>
</ul>
<blockquote><small>NOTE Until IFC2x3 the information had been
provided by the inherited attribute
<i>ObjectType</i>.</small></blockquote>
<p>An <i>IfcOpeningElement</i> has to be inserted into an
<i>IfcElement</i> by using the <i>IfcRelVoidsElement</i>
relationship. The relationship implies a Boolean subtraction
operation between the volume of the voided element and the volume
of the opening. It may be filled by an <i>IfcDoor</i>,
<i>IfcWind</i>ow, or another filling element by using the
relationship <i>IfcRelFillsElements</i>.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 1.0</font></small><br>
<small><font color=""#FF0000"">IFC2x CHANGE The intermediate
ABSTRACT supertypes <i>IfcFeatureElement</i> and
<i>IfcFeatureSubtraction</i> have been added.</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE The attribute
<i>PredefinedType</i> has been added at the end of attribute
list.</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcOpeningElement</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcOpeningElement</i>
are part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_OpeningElementCommon.xml""
target=""SOURCE"">Pset_OpeningElementCommon</a>: common property
set for all opening occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcOpeningElement</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
""../../qto/IfcProductExtension/Qto_OpeningElementBaseQuantities.xml""
target=""SOURCE"">Qto_OpeningElementBaseQuantities</a>: base
quantities for all opening occurrences.</li>
</ul>

<p class=""use-head"">Containment Use Definition</p>
<p>The <i>IfcOpeningElement</i> shall not participate in the
containment relationship, i.e. it is not linked directly to the
spatial structure of the project. It has a mandatory
<i>VoidsElements</i> inverse relationship pointing to the
<i>IfcElement</i> that is contained in the spatial structure.</p>
<ul>
<li>The inverse relationship <i>ContainedInStructure</i> shall be
NIL.</li>
</ul>
<blockquote><small>NOTE See <i>IfcRelVoidsElement</i> for a
diagram on how to apply spatial containment and the voiding
relationship.</small></blockquote>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcOpeningElement</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcOpeningElement</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> should point to the local placement of
the same element, which is voided by the opening, i.e. referred
to by <i>VoidsElement.RelatingBuildingElement</i>.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the 'Body', and 'Box' representations are
supported. The 'Box' representation includes the representation
type 'BoundingBox' and is explained at
<i>IfcFeatureElement</i>.</p>
<p><b>Body Representation</b></p>
<p>The 'Body' representation of <i>IfcOpeningElement</i> can be
represented using the representation types 'SweptSolid', and
'Brep'. The representation type 'Brep' is explained at
<i>IfcFeatureElement</i></p>
<p><i>Swept Solid Representation Type with Horizontal
Extrusion</i></p>
<p>The 'SweptSolid' geometric representation of
<i>IfcOpeningElement</i>, using horizontal extrusion direction
(for walls), is defined using the swept area solid geometry. The
following attribute values for the <i>IfcShapeRepresentation</i>
holding this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required, the
set of <i>IfcShapeRepresentation.Items</i> may include a single,
or multiple, instances of <i>IfcExtrudedAreaSolid</i>.</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded horizontally
(i.e. perpendicular to the extrusion direction of the voided
element), e.g. for wall openings, or vertically (i.e. in the
extrusion direction of the voided element), e.g., for floor
openings. If multiple instances of <i>IfcExtrudedAreaSolid</i>
are used, the extrusion direction of each extrusion should be
equal.</li>
</ul>
<blockquote><small>NOTE In case of non-parallel jambs, the shape
representation shall be a 'SweptSolid' representation with
vertical extrusion.</small></blockquote>

<p>Figure 34 illustrates an opening with horizontal extrusion.</p>
<blockquote class=""note"">NOTE  The local placement directions for the <i>IfcOpeningElement</i> are only given as an example, other directions are valid as well.</blockquote>
<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""600""><img src=
""figures/IfcOpeningElement_Horizontal-Layout1.png"" alt=""standard opening"" border=""0"" height=""400"" width=""600""></td>
<td align=""left"" valign=""top""></td></tr>
<tr><td><p class=""figure"">Figure 34 &mdash; Opening with full extrusion</p></td></tr>
</table>

<p>Figure 35 illustrates an opening for a recess.</p>
<blockquote class=""note"">NOTE  The local placement directions for the <i>IfcOpeningElement</i> are only given as an example, other directions are valid as well.</blockquote>
<blockquote class=""note"">NOTE  Rectangles are now defined centric, the placement
location has to be set:</blockquote>
<ul>
<li><i>IfcCartesianPoint</i>(XDim/2,YDim/2)</small></li>
</ul>
<table cellpadding=""2"" cellspacing=""2"" summary=""recess"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""600""><img src=
""figures/IfcOpeningElement_Recess-Layout1.png"" alt=""recess""
border=""0"" height=""400"" width=""600""></td>
<td align=""left"" valign=""top""></td></tr>
<tr><td><p class=""figure"">Figure 35 &mdash; Opening with recess extrusion</p></td></tr>
</table>

<p><i>Swept Solid Representation with Vertical Extrusion</i></p>
<p>The 'SweptSolid' geometric representation of
<i>IfcOpeningElement</i>, using vertical extrusion direction (for
walls), is defined using the swept area solid geometry, however
the extrusion direction may be vertical, i.e. in case of a wall
opening, the extrusion would be in the direction of the wall
height. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required, the
set of <i>IfcShapeRepresentation.Items</i> may include a single,
or multiple, instances of <i>IfcExtrudedAreaSolid</i>.</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded vertically,
i.e. for wall openings along the extrusion direction of the
voided element.˙ If multiple instances of
<i>IfcExtrudedAreaSolid</i> are used, the extrusion direction
should be equal.</li>
</ul>
<p>Vertical extrusions shall be used when an opening or recess
has a non rectangular foot print geometry that does not change
along the height of the opening or recess.</p>
<p>Figure 36 shows a vertical extrusion with multiple extrusion bodies for the opening. Each extrusion body has a different extrusion lenght.</p>
<blockquote class=""note"">NOTE  The local placement directions for the <i>IfcOpeningElement</i> are only given as an example, other directions are valid as well.</blockquote>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""vertical extrusion"">
<tr><td align=""left"" valign=""top"" width=""600""><img src=""figures/IfcOpeningElement_Vertical-Layout1.png"" alt=""vertical extrusion"" border=""0"" height=""400"" width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 36 &mdash; Opening with multiple extrusions</p></td></tr>
</table>
</EPM-HTML>"
670;IfcOpeningStandardCase;"<EPM-HTML>
<p>The standard opening,
<i>IfcOpeningStandardCase</i>, defines an opening with certain
constraints for the dimension parameters, position within the
voided element, and with certain constraints for the geometric
representation. The <i>IfcOpeningStandardCase</i> handles all
cases of openings, that:</p>
<ul>
<li>are true openings by cutting through the body of the voided
element, i.e. where the opening depth is &gt;= to the thickness
of the element,</li>
<li>are extruded perpendicular to the wall plane in case of
openings in a wall</li>
<li>are extruded perpendicular to the slab plane in case of
openings in a slab</li>
<li>have a local placement relative to the local placement of the
voided element</li>
<li>have a 'Body' shape representation with 'SweptSolid'
representation type</li>
<li>have only a single extrusion body within the 'Body' shape
representation</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the
<i>IfcOpeningStandardCase</i> are defined at the supertype
<i>IfcOpeningElement</i>.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcOpeningStandardCase</i>
are defined at the supertype <i>IfcOpeningElement</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcOpeningStandardCase</i> are defined at the supertype
<i>IfcOpeningElement</i>.</p>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcOpeningStandardCase</i>
is given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The following constraint is mandatory for
<i>IfcOpeningStandardCase</i></p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> should point to the local placement of
the same element, which is voided by the opening, i.e. referred
to by <i>VoidsElement.RelatingBuildingElement</i>.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>The geometric representation of <i>IfcOpeningStandardCase</i>
is defined using the following multiple shape representations for
its definition:</p>
<ul>
<li>Body: A SweptSolid representation defining the 3D subtraction
shape of the standard opening</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcOpeningStandardCase</i> is
represented using the representation type 'SweptSolid'.</p>
<p><i>Swept Solid Representation Type with Horizontal
Extrusion</i></p>
<p>The standard geometric representation of
<i>IfcOpeningStandardCase</i> is defined using the 'SweptSolid'
representation. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used::</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: a single <i>IfcExtrudedAreaSolid</i> is
required</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded horizontally
(i.e. perpendicular to the extrusion direction of the voided
element) for wall openings, or vertically (i.e. in the extrusion
direction of the voided element), for slab openings.</li>
</ul>

<p>As shown in Figure 37, the orientation of the opening profile that is extruded
for the opening body shall guarantee the following interpretation
of dimension parameter for rectangular openings:</p>
<ul>
<li><i>IfcRectangleProfileDef.YDim</i> interpreted as
opening width</li>
<li><i>IfcRectangleProfileDef.XDim</i> interpreted as
opening height</li>
</ul>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""600""><img src=
""figures/IfcOpeningStandardCase_Wall-Layout1.png"" alt=
""standard opening"" border=""0"" height=""400"" width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 37 &mdash; Opening standard representation</p></td></tr>
</table>

</EPM-HTML>"
676;IfcRelFillsElement;"<EPM-HTML> 

<p><i>IfcRelFillsElement</i> is an objectified relationship between an opening element and an element that fills (or partially fills) the opening element. It is an one-to-one relationship.</p>

<blockquote class=""note"">NOTE view definitions or implementer agreements may restrict an opening to be filled by one filling element only.</blockquote>

<blockquote class=""history"">HISTORY New entity in IFC Release 1.0</blockquote>

<p>As shown in Figure 40, the insertion of a door into a wall is represented by two separate relationships. First the door opening is created within the wall by <i>IfcWall(StandardCase) o-- IfcRelVoidsElement --o IfcOpeningElement</i>, then the door is inserted within the opening by <i>IfcOpeningElement o-- IfcRelFillsElement --o IfcDoor</i>.</p>

<table border=""0"" cellpadding=""0"" cellspacing=""0"" width=""502"" summary=""example for filling"">
<tr><td><img src=""figures/IfcRelFillsElements-Fig1.png"" alt=""relationships for filling"" width=""501"" height=""401"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 40 &mdash; Relationships for element filling</p></td></tr>
</table>

</EPM-HTML>"
679;IfcElementAssembly;"<EPM-HTML>
<p>The <i>IfcElementAssembly</i>
represents complex element assemblies aggregated from several
elements, such as discrete elements, building elements, or other
elements.</p>
<blockquote><small>EXAMPLE Steel construction assemblies, such as
trusses and different kinds of frames, can be represented by the
<i>IfcElementAssembly</i> entity. Other examples include slab
fields aggregated from a number of precast concrete slabs or
reinforcement units made from several reinforcement bars. Also
bathroom units, staircase sections and other premanufactured or
precast elements are examples of the general
<i>IfcElementAssembly</i> entity</small></blockquote>
<blockquote><small>NOTE The <i>IfcElementAssembly</i> is a
general purpose entity that is required to be decomposed. Also
other subtypes of IfcElement can be decomposed, with some
dedicated entities such as <i>IfcWallElementedCase</i> and
<i>IfcSlabElementedCase</i>.</small></blockquote>
<p>The assembly structure can be nested, i.e. an
<i>IfcElementAssembly</i> could be an aggregated part within
another <i>IfcElementAssembly</i>.</p>
<blockquote><small>NOTE View definitions and/or implementer
agreements may restrict the number of allowed levels of
nesting.</small></blockquote>
<blockquote class=""history"">HISTORY New Entity for
Release IFC2x Edition 2.</blockquote>

<p class=""use-head"">Containment Use Definition</p>
<p>The <i>IfcElementAssembly</i> should have (and in most
implementation scenarios it is mandatory) a relationship for its
hierachical containment in the spatial structure of the
project.</p>
<ul>
<li>The <i>IfcElementAssembly</i> is places within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of <i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
</ul>
<p>The <i>IfcElementAssembly</i> shall represent an aggregate,
i.e. it should have other elements, being subtypes of
<i>IfcElement</i>, as contained (sub)parts.</p>
<ul>
<li>The <i>IfcElementAssembly</i> is an aggregate i.e. being
composed by other elements and acting as an assembly using the
objectified relationship <i>IfcRelAggregates</i>, refering to it
by its inverse attribute
<i>SELF\IfcObjectDefinition.IsDecomposedBy</i>. Components of an
assembly are described by instances of subtypes of
<i>IfcElement</i>.</li>
<li>In this case, the contained˙subtypes of <i>IfcElement</i>
shall not be additionally contained in the project spatial
hierarchy, i.e. the inverse attribute
<i>SELF\IfcElement.ContainedInStructure</i> of those
<i>IfcElement</i>'s shall be <i>NIL.</i></li>
</ul>

<p>Figure 27 illustrates spatial containment and element aggregation relationships.</p>
<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=
""containment"">
<tr><td><img src=""figures/IfcElementAssembly-Containment.png"" alt=""containment relationships"" width=""500"" height=""250"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 27 &mdash; Element assembly containment</p></td></tr>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcElementAssembly</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcElementAssembly</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><u><b>Geometric Representations</b></u></p>
<p>The geometry of an <i>IfcElementAssembly</i> is generally
formed from its components, in which case it does not need to
have an explicit geometric representation. In some cases it may
be useful to also expose an own explicit representation of the
aggregate.</p>
<blockquote><small>NOTE˙ View definitions or implementer
agreements may further constrain the applicability of certain
shape representations at the <i>IfcElementAssembly</i> in respect
of the shape representations of its parts.</small></blockquote>
<p><u>Informal proposition</u></p>
<ol>
<li>The <i>IfcElementAssembly</i> shall have an aggregation
relationship to the contained parts, i.e. the (INV)
<i>IsDecomposedBy</i> relationship shall be utilzed.</li>
</ol>
</EPM-HTML>
"
688;IfcVirtualElement;"<EPM-HTML>

<p>A virtual element is a special element used to provide imaginary boundaries, such as between two adjacent, but not separated, spaces. Virtual elements are usually not displayed and does not have quantities and other measures. Therefore <i>IfcVirtualElement</i> does not have material information and quantities attached.</p>

<blockquote class=""note"">NOTE The main purpose of <i>IfcVirtualElement</i> is the provision of a virtual space boundary. The <i>IfcVirtualElement</i> may provide the 2D curve or 3D surface representation of the virtual space connection and is referenced by two instances of <i>IfcRelSpaceBoundary</i>, each pointing to one of the two adjacent <i>IfcSpaces</i>.</blockquote>

<blockquote class=""history"">HISTORY New entity in IFC Release 2x2 Addendum.</blockquote>
<blockquote class=""change-ifc2x3"">IFC2x2 CHANGE: The entity <i>IfcVirtualElement</i> has been added. Upward compatibility for file based exchange is guaranteed.</blockquote>

<p class=""use-head"">Space Boundary Use Definition</p>
<p>The <i>IfcVirtualElement</i> is mainly used to define a virtual boundary between two spaces. Figure 63 describes how to use <i>IfcRelSpaceBoundary</i> in conjunction with <i>IfcVirtualElement</i> to define space boundaries.</p>

<table>
<tr><td><img src=""figures/IfcVirtualElement_SpaceBoundaries.png"" alt=
""space boundary"" width=""800"" height=""300""></td></tr>
<tr><td><p class=""figure"">Figure 63 &mdash; Virtual element space boundaries</p></td></tr>
</table>

<p class=""use-head"">Geometry Use Definition</p>
<p>The geometric representation of any <i>IfcVirtualElement</i>
is given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcVirtualElement</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>Geometric Representation</b></p>
<p>Currently, the use of 'FootPrint' and 'Surface' representation
is supported.</p>
<p><b>FootPrint Representation</b></p>
<p>The 2D geometric representation of <i>IfcVirtualElement</i> is
defined using the 'FootPrint' representation.</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> = 'Curve2D'
or 'GeometricCurveSet' .</li>
</ul>
<p>The following constraints apply to the 2D FootPrint
representation:</p>
<ul>
<li>'Curve2D': <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i> or
<i>IfcCompositeCurve</i></li>
<li>'GeometricCurveSet': a list of 2D curves within the
constraints shown above.</li>
</ul>
<p><b>Surface Representation</b></p>
<p>The 3D geometric representation of <i>IfcVirtualElement</i> is
defined using a surface geometry.</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Surface'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Surface3D' or 'GeometricSet .</li>
</ul>
<p>The following constraints apply to the 3D surface
representation:</p>
<ul>
<li>'Surface3D': <i>IfcSurfaceOfLinearExtrusion</i>,
<i>IfcCurveBoundedPlane</i>, <i>IfcCurveBoundedSurface</i>,
<i>IfcRectangularTrimmedSurface</i></li>
<li style=""list-style-type: none;""><small>in case of an
<i>IfcSurfaceOfLinearExtrusion</i></small>
<ul>
<li><small><u>Profile</u>:
<i>IfcArbitraryOpenProfileDef</i></small></li>
<li><small><u>Extrusion</u>: The extrusion direction shall be
vertically, i.e., along the positive Z Axis of the co-ordinate
system of the containing spatial structure element.</small></li>
</ul>
</li>
<li style=""list-style-type: none;""><small>in case of an
<i>IfcCurveBoundedPlane</i>, <i>IfcCurveBoundedSurface</i>,
<i>IfcRectangularTrimmedSurface</i></small>
<ul>
<li><small><u>Extrusion</u>: The <i>BasisSurface</i> shall be a
surface that is upright, i.e. standing perpendicular to the xy
place of the co-ordinate system of the containing spatial
structure element.</small></li>
</ul>
</li>
<li>'GeometricSet': a list of 3D surfaces within the constraints
shown above.</li>
</ul>
</EPM-HTML>"
689;IfcGeographicElement;"<EPM-HTML> 
<p><u>Definition from IAI</u>: An <i>IfcGeographicElement</i> is
a generalization of all elements within a geographical landscape.
It includes occurrences of typical geographical element, often
referred to as features, such as roads, zones, trees, etc. Common
type information behind several occurrences of
<i>IfcGeographicElement</i> is provided by the
<i>IfcGeographicElementType</i>.˙</p>
<blockquote><small><font color=""#0000FF"">HISTORY ˙New entity in
Release IFC2x4.</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p>An <i>IfcGeographicElement</i> defines the occuurence of any
element within a geographic landscape, common information about
geographic elements is handled by
<i>IfcGeographicElementType</i>. The
<i>IfcGeographicElementType</i> (if present) may establish the
common˙type name, usage (or predefined) type, common set of
properties and common shape representations (using
<i>IfcRepresentationMap</i>). The <i>IfcGeographicElementType</i>
is attached using the <i>IfcRelDefinedByType.RelatingType</i>
objectified relationship and is accessible by the inverse
<i>IsDefinedBy</i> attribute.</p>
<p><b><u>Classification Use Definition</u></b></p>
<p>An <i>IfcGeographicElement</i> might be further qualified by
referencing a feature catalog as a particular classification. The
feature classification is assigned using the inverse relationship
<i>HasAssociations</i> pointing to
<i>IfcClassificationReference</i>. The attributes should have the
following meaning:</p>
<ul>
<li>Catalog : <i>IfcClassification.Name</i></li>
<li>Identity:
<i>IfcClassificationReference.ItemReference</i></li>
<li>ElementName: <i>IfcClassificationReference.Name</i></li>
<li>if there is a differentiation between an main element and a
sub element without a unique notation facet, then the main
element and sub element(s) can be established by using the
subtype
<ul>
<li style=""list-style: none"">
<i>IfcClassificationReferenceWithFacets.ItemReferenceFacets</i></li>
</ul>
</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcGeographicElement</i>, as any subtype of
<i>IfcElement</i>, may participate in two different containment
relationships. The first (and in most implementation scenarios
mandatory) relationship is the hierachical spatial containment,
the second (optional) relationship is the aggregation within
an˙element assembly.</p>
<ul>
<li>The <i>IfcGeographicElement</i> is places within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcSite</i> being the default container.</li>
<li>The <i>IfcGeographicElement</i> may be aggregated into an
element assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcGeographicElement</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcGeographicElement</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><i><b>Geometric Representation</b></i></p>
<p><b>GeometricCurveSet and GeometricSet Representation</b></p>
<p>The standard representation of <i>IfcGeographicElement</i> is
defined using 'GeometricCurveSet' or, when including surfaces,
the 'GeometricSet' geometry. This also supports a 2D
representation of <i>IfcGeographicElement</i>.˙</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint' for 2D
representation</li>
<li><i>RepresentationType</i> :˙'GeometricCurveSet'
or˙'GeometricSet'</li>
</ul>
<p><b>Annotation2D Representation</b></p>
<p>Additional annotation objects, like text or hatching, and
style information to the 2D representations, may be exchanged
using the 'Annotation2D' representation. Style information is
assigned to the geometric representation items within the set of
<i>Items</i> at <i>IfcShapeRepresentation</i> using the inverse
StyledByItem relationship.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint' for 2D
representation</li>
<li><i>RepresentationType</i> :˙'Annotation2D'</li>
</ul>
<p><b>SurfaceModel and Brep Representation</b></p>
<p>For full 3D representations, the use of 'SurfaceModel' and
'Brep' geometry is supported. This supports a 3D representation,
including support for 3D digital terrain models.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body' for 3D
representation</li>
<li><i>RepresentationType</i> :˙'SurfaceModel' or˙'Brep'</li>
</ul>
<b>MappedRepresentation Representation</b><br>
<p>When using the <i>IfcGeographicElement</i> in conjunction with
the <i>IfcGeographicElementType</i> having
<i>RepresentationMaps</i> defined, the geometric representation
of˙<i>IfcGeographicElement˙</i>shall be based on
'MappedRepresentation', referencing the
<i>IfcRepresentationMap</i> given at the type object.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint' for 2D
representation, 'Body' for 3D representation</li>
<li><i>RepresentationType</i> :˙'MappedRepresentation'</li>
</ul>
</EPM-HTML>"
693;IfcRelInterferesElements;"<EPM-HTML>
<p><u>Definition from IAI</u>: The
<i>IfcRelInterferesElements</i> objectified relationship
indicates that two elements interfere. Interference is a spatial
overlap between the two elements. It is a 1 to 1 relationship.
The concept of two elements interfering physically or logically
is described independently from the elements. The interference
may be related to the shape representation of the entities by
providing an interference geometry.</p>
<ul>
<li>When the interference geometry is available it can be passed
by the optional attribute <i>InterferenceGeometry</i> pointing to
<i>IfcConnectionGeometry</i>. The connection geometry is provided
as a point, curve, surface, or volume within the local placement
coordinate systems of the connecting elements. The
<i>IfcConnectionVolumeGeometry</i> is the default type to be used
for interference in 3D space, as indicated in e.g. clash
detections.</li>
<li>If the interference geometry is omitted then the interference
is provided as a logical relationship. Under this circumstance,
the connection point, curve, surface, or solid has to be
recalculated by the receiving application.</li>
</ul>
<p>The <i>RelatingElement</i> and <i>RelatedElement</i> define
the two elements in the relationship, that may have different
roles. This is controlled by the attribute
<i>ImpliedOrder</i>.</p>
<ul>
<li><i>ImpliedOrder</i>=TRUE˙ The <i>RelatingElement</i>
constitutes the primary element of the interference relationship.
If the interference is to be resolved by subtracting the
overlapping part, it should be subtracted from the
<i>RelatingElement</i>. The net result would be the
<i>RelatingElement</i> subtracted by the
<i>InterferenceGeometry</i>. This would be the case in
interference relationships where the <i>RelatedElement</i>
creates a void in the <i>RelatingElement</i> dynamically.</li>
<li><i>ImpliedOrder</i>=FALSE˙ The <i>RelatingElement</i> and
<i>RelatedElement</i> have no priority among each other. If the
interference is to be resolved then no information about whether
the <i>InterferenceGeometry</i> should be subtracted from the
<i>RelatingElement</i> or thed <i>RelatedElement</i> can be
traced. This would be the case for clash detection results.</li>
<li><i>ImpliedOrder</i>=UNKNOW˙ No information about the
priorities is provided.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY˙ New entity in
IFC2x4.</font></small></blockquote>
</EPM-HTML>"
700;IfcRelReferencedInSpatialStructure;"<EPM-HTML>
    <p>
      The objectified relationship,
      <i>IfcRelReferencedInSpatialStructure</i> is used to
      assign elements in addition to those levels of the project
      spatial˙structure, in which they are referenced, but not
      primarily contained.˙
    </p>
    <blockquote>
      <p>
        <small>NOTE ˙The primary containment relationship between
        an element and the spatial structure is handled
        by˙<i>IfcRelContainsInSpatialStructure</i>.</small>
      </p>
    </blockquote>
    <p>
      Any element can be referenced˙to zero, one or several
      levels of the spatial structure. Whereas the
      <i>IfcRelContainsInSpatialStructure</i> relationship is
      required to be hierarchical (an element can only be
      contained in exactly one spatial structure element), the
      <i>IfcRelReferencedInSpatialStructure</i> is not restricted
      to be hierarchical.
    </p>
    <blockquote>
      <p>
        <small>EXAMPLE A wall might be normally contained within
        a storey, and since it does not span through several
        stories, it is not referenced in any additional storey.
        However a curtain wall might span through several
        stories, in this case it can be contained within the
        ground floor, but it would be referenced by all
        additional stories, it spans.</small>
      </p>
    </blockquote>
    <p>
      Predefined spatial structure elements to which elements can
      be assigned are
    </p>
    <ul>
      <li>site as <i>IfcSite</i>
      </li>
      <li>building as <i>IfcBuilding</i>
      </li>
      <li>storey as <i>IfcBuildingStorey</i>
      </li>
      <li>space as <i>IfcSpace</i>
      </li>
    </ul>
<p>Elements can also be references in a spatial zone that is provided as <i>IfcSpatialZone</i>.</p>
    <p>
      The same element can be assigned to different spatial
      structure elements depending on the context.
    </p>
    <blockquote>
        <small><font color=""#0000FF"">HISTORY New entity
        in˙Release IFC2x Edition 3.</font></small>
    </blockquote>
    <p class=""use-head"">Use Definition</p>
<p>Figure 41 shows the use of <i>IfcRelContainedInSpatialStructure</i> and <i>IfcRelReferencedInSpatialStructure</i> to assign an <i>IfcCurtainWall</i>˙to two different levels within the spatial structure. It is primarily contained within the ground floor, and additionally referenced within the first and second floor.</p>

    <table cellpadding=""2"" cellspacing=""2"" width=""80%"">
      <tbody>
        <tr valign=""top"">
          <td align=""left"" valign=""top""><img alt=""reference and containment"" src=""figures/IfcRelReferencedInSpatialStructure-Fig1.png"" height=""601"" width=""601""><br>
          </td>
        </tr>
        <tr>
          <td><p class=""figure"">Figure 41 &mdash; Relationship for spatial structure referencing</p></td>
        </tr>
      </tbody>
    </table>

</EPM-HTML>"
704;IfcRelConnectsWithRealizingElements;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>:
      <i>IfcRelConnectsWithRealizingElements</i> defines a
      generic relationship that is made between two elements that
      require the realization of that relationship by means of
      further realizing elements.
    </p>
    <p>
      An <i>IfcRelConnectsWithRealizingElements</i> is a
      specialization of <i>IfcRelConnectsElement</i> where the
      connecting operation has the additional attribute of (one
      or many) realizing elements that may be used to realize or
      further qualify the relationship. It is defined as a
      ternary relationship.
    </p>
    <blockquote>
      <p>
        <font size=""-1"">EXAMPLE: It may be used to describe the
        attachment of one element to another where the attachment
        is realized by a 'fixing' element such as a bracket. It
        may also be used to describe the mounting of one element
        onto another such as the requirement for the mounting
        major plant items onto builders work bases and/or
        anti-vibration isolators.</font>
      </p>
    </blockquote>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY: New entity in
        Release IFC2x Edition 2.</font></small>
      </p>
    </blockquote>
</EPM-HTML>"
707;IfcRelContainedInSpatialStructure;"<EPM-HTML> 
    <p>
      This objectified relationship,
      <i>IfcRelContainedInSpatialStructure</i>, is used to assign
      elements to a certain level of the spatial project
      structure. Any element can only be assigned once to a
      certain level of the spatial structure. The question, which
      level is relevant for which type of element, can only be
      answered within the context of a particular project and
      might vary within the various regions.
    </p>
    <blockquote>
      <p>
        <small>EXAMPLE A multi-storey space is contained (or
        belongs to) the building storey at which its ground level
        is, but it is referenced by all the other building
        storeys, in which it spans. A lift shaft might be
        contained by the basement, but referenced by all storeys,
        through which it spans.</small>
      </p>
    </blockquote>
    <p>
      The containment relationship of an element within a
      spatial structure has to be a hierarchical relationship, an
      element can only be contained within a single spatial
      structure element. The reference relationship between an
      element and the spatial structure may not be hierarchical,
      i.e. an element can reference many spatial structure
      elements.
    </p>
    <blockquote>
      <p>
        <small>NOTE The reference relationship is expressed by
        <i>IfcRelReferencedInSpatialStructure</i>.</small>
      </p>
    </blockquote>
    <p>
      Predefined spatial structure elements to which elements can
      be assigned are
    </p>
    <ul>
      <li>site as <i>IfcSite</i>
      </li>
      <li>building as <i>IfcBuilding</i>
      </li>
      <li>storey as <i>IfcBuildingStorey</i>
      </li>
      <li>space as <i>IfcSpace</i>
      </li>
    </ul>
    <p>
      Occurrences of the same element type can be assigned to
      different spatial structure elements depending on the
      context of the occurrence.
    </p>
    <blockquote>
      <p>
        <font size=""-1"">EXAMPLE A wall might be normally assigned
        to a storey, however the curtain wall might be assigned
        to the building and the retaining wall in the terrain
        might be assigned to the site.</font>
      </p>
    </blockquote>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in IFC
        Release 2x.</font></small>
      </p>
    </blockquote>
    <blockquote>
      <font color=""#FF0000"" size=""-1"">IFC2x PLATFORM CHANGE: The
      data type of the attribute <i>RelatedElements</i> has been
      changed from <i>IfcElement</i> to its supertype
      <i>IfcProduct</i> with upward compatibility for file based
      exchange.</font>
    </blockquote>
    <p class=""use-head"">Containment Use Definition</p>
    <p>Figure 39 shows the use of <i>IfcRelContainedInSpatialStructure</i> to assign a stair and two walls to two different levels within the spatial structure.</p>
    <table cellpadding=""2"" cellspacing=""2"">
      <tr valign=""top"">
        <td valign=""top"" align=""left"">
          <img src=
          ""figures/IfcRelContainedInSpatialStructure-Fig1.png""
          alt=""fig1"" width=""556"" height=""556"" border=""0"">˙
        </td>
      </tr>
      <tr><td><p class=""figure"">Figure 39 &mdash; Relationship for spatial structure containment</p></td></tr>
    </table>
</EPM-HTML>"
711;IfcGrid;"<EPM-HTML>
<p><i>IfcGrid</i> ia a planar design
grid defined in 3D space used as an aid in locating structural and
design elements. The position of the grid (<i>ObjectPlacement</i>)
is defined by a 3D coordinate system (and thereby the design grid
can be used in plan, section or in any position relative to the
world coordinate system). The position can be relative to the
object placement of other products or grids. The XY plane of the 3D
coordinate system is used to place the grid axes, which are 2D
curves (for example, line, circle, trimmed curve, polyline, or composite
curve).</p>
<p>The inherited attributes <i>Name</i> and <i>Description</i> can
be used to define a descriptive name of the grid and to indicate
the grid's purpose.&nbsp;A grid is defined by (normally) two, or
(in case of a triangular grid) three lists of grid axes. The
following table shows some examples.</p>
<p>A grid may support a rectangular layout (Figure 28), a radial layout (Figure 29), or a triangular layout (Figure 30).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr>
<td width=""320""><img src=""figures/IfcDesignGrid-Type1.gif"" alt=""1"" border=""0"" height=""211"" width=""306""></td>
<td width=""320""><img src=""figures/IfcDesignGrid-Type2.gif"" alt=""2"" border=""0"" height=""211"" width=""306""></td>
<td width=""320""><img src=""figures/IfcDesignGrid-Type3.gif"" alt=""3"" border=""0"" height=""211"" width=""306""></td>
</tr>
<tr>
<td width=""320""><p class=""figure"">Figure 28 &mdash; Grid rectangular layout</p></td>
<td width=""320""><p class=""figure"">Figure 29 &mdash; Grid radial layout</p></td>
<td width=""320""><p class=""figure"">Figure 30 &mdash; Grid triangular layout</p></td>
</tr>
</tbody>
</table>

<p>The grid axes, defined within the design grid, are those
elements to which project objects will be placed relatively using
the <i>IfcGridPlacement</i>.</p>

<blockquote class=""history"">HISTORY New entity in IFC Release 1.0.</blockquote>
<p><u>Informal Proposition</u></p>
<ol>
<li>Grid axes, which are referenced in different lists of axes
(UAxes, VAxes, WAxes) shall not be parallel.</li>
<li>Grid axes should be defined such as there are no two grid axes
which intersect twice (see Figure 31).
<ul>
<li>left side: ambiguous intersections A1 and A2, a grid containing
such grid axes is not a valid design grid.</li>
<li>right side: the conflict can be resolved by splitting one grid
axis in a way, such as no ambiguous intersections exist.</li>
</ul>
</li>
</ol>

<table cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top""><td align=""left"" valign=""top"" width=""320""><img src=
""figures/IfcDesignGrid-IP2.gif"" alt=""IP2"" border=""0"" height=""97""
width=""306""></td></tr>
<tr><td><p class=""figure"">Figure 31 &mdash; Grid intersections</p></td></tr>
</tbody>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcGrid</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcGrid</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to a
spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'GeometricCurveSet' is supported.</p>
<p><b>GeometricCurveSet representation</b></p>
<p>The 2D geometric representation of <i>IfcGrid</i> is defined
using the 'GeometricCurveSet' geometry. The following attribute
values should be inserted</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet' .</li>
</ul>
<p>The following constraints apply to the 2D representation:</p>
<ul>
<li>The <i>IfcGeometricCurveSet</i> shall be an (and the only)
<i>Item</i> of the <i>IfcShapeRepresentation</i>. It should contain
an <i>IfcGeometricCurveSet</i> containing subtypes of
<i>IfcCurve</i>, each representing a grid axis. Applicable subtypes
of <i>IfcCurve</i> are: <i>IfcPolyline</i>, <i>IfcCircle</i>,
<i>IfcTrimmedCurve</i> (based on <i>BaseCurve</i> referencing
<i>IfcLine</i> or <i>IfcCircle</i>).&nbsp;</li>
<li>Each subtype of <i>IfcCurve</i> may have a curve style
assigned, using <i>IfcAnnotationCurveOccurrence</i> referencing
<i>IfcCurveStyle</i>.</li>
<li>Optionally the grid axis labels may be added as
<i>IfcTextLiteral</i>, and they may have text styles assigned,
using <i>IfcAnnotationTextOccurrence</i> referencing
<i>IfcTextStyle</i>.</li>
</ul>


<p>As shown in Figure 32, the <i>IfcGrid</i> defines a placement coordinate system using the <i>ObjectPlacement</i>. The XY plane of the coordinate system is used to place the 2D grid axes. The <i>Representation</i> of <i>IfcGrid</i> is defined using <i>IfcProductRepresentation</i>, referencing an <i>IfcShapeRepresentation</i>, that includes&nbsp;<i>IfcGeometricCurveSet</i> as <i>Items</i>. All grid axes are added as <i>IfcPolyline</i> to the <i>IfcGeometricCurveSet</i>.</p>

<table cellpadding=""2"" cellspacing=""2""><tbody>
<tr><td><img src=""figures/IfcDesignGrid-Layout1.gif"" alt=""design grid"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 32 &mdash; Grid layout</p></td></tr>
</tbody></table>

<p>As shown in Figure 33, the attributes <i>UAxes</i> and <i>VAxes</i> define lists of <i>IfcGridAxis</i> within the context of the&nbsp;grid. Each instance of <i>IfcGridAxis</i> refers to the same instance of <i>IfcCurve</i> (here the subtype <i>IfcPolyline</i>) that is contained within the <i>IfcGeometricCurveSet</i> that represents the <i>IfcGrid</i>.</p>

<table cellpadding=""2"" cellspacing=""2""><tbody>
<tr><td><img src=""figures/IfcGrid-Representation.png"" alt=""representation of a design grid"" width=""501"" height=""621"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 33 &mdash; Grid representation</p></td></tr>
</tbody></table>

</td>
</tr>
</tbody>
</table>

</EPM-HTML>"
717;IfcAnnotation;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: An annotation is a graphical
      representation within the geometric (and spatial) context
      of a project, that adds a note or meaning to the objects
      which constitutes the project model. Annotations include
      additional line drawings, text, dimensioning, hatching and
      other forms of graphical notes.
    </p>
    <blockquote>
      <p>
        <small>NOTE Additional presentation information (often
        2D) such as tag number, hatching, etc., that is directly
        related to a particular product representation is
        included within the <i>IfcProductDefinitionShape</i>
        having various <i>IfcShapeRepresentation</i>'s of the
        <i>IfcElement</i> (and its subtypes). Only those
        presentation information, that cannot be directly related
        to a single product, have to be wrapped within the
        <i>IfcAnnotation</i>.</small>
      </p>
    </blockquote>
    <p>
      If available, the annotation should be related to the
      spatial context of the project, by containing the
      annotation within the appropriate level of the building
      structure (site, building, storey, or space). This is
      handled by the <i>IfcRelContainedInSpatialStructure</i>
      relationship.
    </p>
    <blockquote>
      <p>
        <font color=""#0000FF"" size=""-1"">HISTORY: New entity in
        Release IFC2x Edition 2.</font>
      </p>
    </blockquote>
    <p>
      <u><b>Use definition</b></u>
    </p>
    <p>
      The <i>IfcAnnotation</i> can provide specific 0D, 1D, and
      2D geometric items as representation of the annotation,
      offering annotation point, curves, and surfaces.
    </p>
    <ul>
      <li>
        <b>'Annotation point'</b> is an annotation provided by a
        point that has additional semantic. The inherited
        attribute <i>ObjectType</i> should be used to capture the
        type of point annotation, some predefined values are:
      </li>
      <li style=""list-style: none"">
        <ul>
          <li>'<b>Survey</b>': A survey point has a set of
          cartesian coordinates determined by its location at
          point. These coordinates are determined relative to the
          coordinates of a reference point, which acts as the
          datum for the survey. The difference in elevation of
          the survey points enables terrain to be determined.<br>

            <br>
          </li>
        </ul>
      </li>
      <li>
        <b>'Annotation curve'</b> is an annotation provided by a
        curve that has additional semantic. The inherited
        attribute <i>ObjectType</i> should be used to capture the
        type of curve annotation, some predefined values are:
      </li>
      <li style=""list-style: none"">
        <ul>
          <li>'<b>ContourLine</b>': A line of constant
          elevation typically used on geographic maps where the
          spacing of lines at constant intervals of elevation may
          be used as an indication of slope.
          </li>
          <li>'<b>IsoBar</b>': A line of constant pressure
          typically used on weather maps or to show pressure
          gradient in spaces, chambers or externally.
          </li>
          <li>'<b>IsoLux</b>': A line of constant illumination
          typically used to show the distribution of illumination
          levels and/or daylighting in a space or externally.
          </li>
          <li>'<b>IsoTherm</b>': A line of constant temperature
          typically used to show the distribution and effect of
          heating or cooling within a space or to show
          temperature distribution on a geographic map.<br>
            <br>
          </li>
        </ul>
      </li>
      <li>
        <b>'Annotation surface'</b> is an annotation provided by
        a surface that has additional semantic. The inherited
        attribute <i>ObjectType</i> should be used to capture the
        type of surface annotation, some predefined values are:
      </li>
      <li style=""list-style: none"">
        <ul>
          <li>'<b>SurveyArea</b>': A surface patch based on
          survey points.<br>
            <br>
          </li>
        </ul>
      </li>
    </ul>
    <p>
      <u><b>Geometry Use Definitions</b></u>
    </p>
    <p>
      The geometric representation of any <i>IfcAnnotation</i> is
      given by the <i>IfcProductDefinitionShape</i> and
      <i>IfcLocalPlacement</i> allowing multiple geometric
      representations.
    </p>
    <p>
      <b>Local Placement</b>
    </p>
    <p>
      The local placement for any <i>IfcAnnotation</i> is defined
      in its supertype <i>IfcProduct</i>. It is defined by the
      <i>IfcLocalPlacement</i>, which defines the local
      coordinate system that is referenced by all geometric
      representations.
    </p>
    <ul>
      <li>The <i>PlacementRelTo</i> relationship of
      <i>IfcLocalPlacement</i> shall point (if given) to the
      local placement of the same
      <i>IfcSpatialStructureElement</i>, which is used in the <i>
        ContainedInStructure</i> inverse attribute, or to a
        spatial structure element at a higher level, referenced
        by that.
      </li>
      <li>If the relative placement is not used, the absolute
      placement is defined within the world coordinate system.
      </li>
    </ul>
    <p>
      <i><b>Geometric Representations</b></i>
    </p>
    <p>
      The standard representation of <i>IfcAnnotation</i> is
      defined using 'Annotation2D', when using 2D geometry,
      hatching and text, 'GeometricCurveSet' when using points
      and curves, or, when including als surfaces, the
      'GeometricSet' geometry. Geometric representation items may
      be styled items by adding the style information.
    </p>
    <p>
      <b>Annotation2D Representation</b><br>
      This representation is used, when the representation of the
      <i>IfcAnnotation</i> includes specific drafting
      representation elements. The Annotation may have:
    </p>
    <ul>
      <li>subtypes of <i>IfcPoint</i>, <i>IfcCurve</i> being 2D
      </li>
      <li style=""list-style: none"">directly as <i>Items</i>, or
      within an <i>IfcGeometricCurveSet</i>
      </li>
      <li>subtypes of <i>IfcAnnotationFillArea</i> for hatches
      </li>
      <li>subtypes of <i>IfcDefinedSymbol</i> for symbols
      </li>
      <li>subtypes of <i>IfcTextLiteral</i> for text
      </li>
      <li>subtypes of <i>IfcDraughtingCallout</i> for dimensions
      </li>
    </ul>The following attribute values for the
    <i>IfcShapeRepresentation</i> holding this geometric
    representation shall be used:
    <ul>
      <li>
        <i>RepresentationIdentifier</i> : 'Annotation'
      </li>
      <li>
        <i>RepresentationType</i> : 'Annotation2D'
      </li>
    </ul>
    <p>
      <b>Annotation Curve Representation</b><br>
      This representation is used, when the representation of the
      <i>IfcAnnotation</i> does not includes specific drafting
      representation elements. The Annotation may have:
    </p>
    <ul>
      <li>subtypes of <i>IfcPoint</i>, <i>IfcCurve</i> being 2D
      </li>
      <li style=""list-style: none"">directly as <i>Items</i>, or
      within an <i>IfcGeometricCurveSet</i>
      </li>
    </ul>The following attribute values for the
    <i>IfcShapeRepresentation</i> holding this geometric
    representation shall be used:
    <ul>
      <li>
        <i>RepresentationIdentifier</i> : 'Annotation'
      </li>
      <li>
        <i>RepresentationType</i> : 'GeometricCurveSet'
      </li>
    </ul>
    <p>
      <b>Annotation Surface Representation</b><br>
      This representation is used, when the representation of the
      <i>IfcAnnotation</i> does includes surfaces. The Annotation
      may have:
    </p>
    <ul>
      <li>subtypes of <i>IfcPoint</i>, <i>IfcCurve</i>, or
      <i>IfcSurface</i>
      </li>
      <li style=""list-style: none"">directly as <i>Items</i>, or
      within an <i>IfcGeometricCurveSet</i>
      </li>
    </ul>The following attribute values for the
    <i>IfcShapeRepresentation</i> holding this geometric
    representation shall be used:
    <ul>
      <li>
        <i>RepresentationIdentifier</i> : 'Annotation'
      </li>
      <li>
        <i>RepresentationType</i> : 'GeometricSet'
      </li>
    </ul>
</EPM-HTML>"
719;IfcSpatialZone;"<EPM-HTML>
<p><u>Definition from IAI</u>: A spatial element is the
generalization of all spatial elements that might be used to
define a spatial structure or to define spatial zones.</p>
<ul>
<li>a hierarchical spatial structure element as
<i>IfcSpatialStructureElement</i>
<ul>
<li>a spatial structure is a hiearchical decomposition of the
project. That spatial structure is often used to provide a
project structure to organize a building project.</li>
<li>a spatial project structure might define as many levels of
decomposition as necessary for the building project. Elements
within the spatial project structure are site, building, storey,
and space</li>
</ul>
</li>
<li>a spatial zone as <i>IfcSpatialZone</i>
<ul>
<li>a spatial zone is a non-hierarchical and potentially
overlapping decomposition of the project under some functional
consideration.</li>
<li>a spatial zone might be used to represent a thermal zone, a
construction zone, a lighting zone, a usable area zone.</li>
<li>a spatial zone might have its independent placement and shape
representation.</li>
</ul>
</li>
</ul>
<blockquote><small>NOTE The <i>IfcSpatialZone</i> is different to
the <i>IfcZone</i> entity by allowing an own placement and shape
representation, whereas <i>IfcZone</i> is only a grouping of
<i>IfcSpace</i>'s.</small></blockquote>
<p><b>Attribute Use Definition</b></p>
<p>The <i>IfcSpatialZone</i> inherits and declares these
attributes that shall have the following meaning:</p>
<ul>
<li><i>Name</i>: A number or designator provided by the user or
system for the spatial element, e.g. a space number ""1-003"",
could also be a running number provided by default by the
application</li>
<li><i>LongName</i>: Name of the spatial element provided by the
user, e.g. a space name ""Office"".</li>
<li><i>Description</i>: Any additional description provided by
the user, e.g. a space description ""Corner office with habour
view"".</li>
<li><i>ObjectType</i>: reserved for typing of spatial elements in
case of <i>PredefinedType</i> = .USERDEFINED., restrictions on
applicable values might be published in view definitions or
implementer agreements.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 2x Edition 4.</font></small></blockquote>
</EPM-HTML>"
723;IfcExternalSpatialStructureElement;"<EPM-HTML>
<p><u>Definition from IAI</u>: The external spatial structure
element is an abstract entity provided for different kind of
external spaces, regions, and volumes.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4.</font></small></blockquote>

</EPM-HTML>"
725;IfcExternalSpatialElement;"<EPM-HTML>
<p><u>Definition from IAI</u>: The external spatial element
defines external regions at the building site. Those regions can
be defined:</p>
<ul>
<li>logically - e.g. an instance of
<i>IfcExternalSpatialElement</i> could represent the air space
around the building without having an own shape representation,
or</li>
<li>physically - e.g. an instance of
<i>IfcExternalSpatialElement</i> could represent the sloping
ground around the building to identify the part of the external
building envelop that is below ground.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4.</font></small></blockquote>
</EPM-HTML>"
735;IfcRelServicesBuildings;"<EPM-HTML> 
    <p>
      <u>Definition from IAI</u>: An objectified relationship
      that defines the relationship between a system and the
      sites, buildings, storeys or spaces, it serves. Examples of
      systems are:
    </p>
    <ul>
      <li>building service systems (heating, cooling, waste water
      system) represented by instances of <i>IfcSystem</i>
      </li>
      <li>idealized structural analysis systems represented by
      instances of <i>IfcStructuralAnalysisSystem</i>
      </li>
    </ul>
    <blockquote>
      <p>
        <small><font color=""#0000FF"">HISTORY New entity in IFC
        Release 1.0</font></small>
      </p>
    </blockquote>
    <blockquote>
      <small><font color=""#FF0000"">IFC2x PLATFORM CHANGE˙ The
      data type of the attribute<i>RelatedBuildings</i> has been
      changed from <i>IfcBuilding</i> to its supertype
      <i>IfcSpatialStructureElement</i> with upward compatibility
      for file based exchange. The name
      <i>IfcRelServicesBuildings</i> is a known˙anomaly, as the
      relationship is not restricted to buildings anymore.</font></small>
    </blockquote>
</EPM-HTML>"
738;IfcBuilding;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Construction work that
has the provision of shelter for its occupants or contents as one
of its main purpose and is normally designed to stand permanently
in one place.</p>
<p>A building represents a structure
that provides shelter for its occupants or contents and stands in
one place. The building is also used to provide a basic element
within the spatial structure hierarchy for the components of a
building project (together with site, storey, and space).</p>
<p>A building is (if specified) associated to a site. A building
may span over several connected or disconnected buildings.
Therefore building complex provides for a collection of buildings
included in a site. A building can also be decomposed in
(vertical) parts, where each part defines a building section.
This is defined by the composition type attribute of the
supertype <i>IfcSpatialStructureElements</i> which is interpreted
as follow:</p>
<ul>
<li>COMPLEX = building complex</li>
<li>ELEMENT = building</li>
<li>PARTIAL = building section</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0.</blockquote>

<p class=""use-head"">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcBuilding</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcBuilding</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_BuildingCommon.xml"" target=
""SOURCE"">Pset_BuildingCommon</a>: common property set for all
types of buildings</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_BuildingWaterStorage.xml""
target=""SOURCE"">Pset_BuildingWaterStorage</a>: specific property
set for buildings to capture the water supply requirements</li>
<li><a href=""../../psd/IfcProductExtension/Pset_BuildingUse.xml""
target=""SOURCE"">Pset_BuildingUse</a>: specific property set for
buildings to capture the current and anticipated real estate
context.</li>
<li><a href=
""../../psd/IfcProductExtension/Pset_BuildingUseAdjacent.xml""
target=""SOURCE"">Pset_BuildingUseAdjacent</a>: specific property
set for buildings to capture the use information about the
adjacent buildings.</li>
</ul>

<p class=""use-head"">Quantity Use Definition</p>
<p>The quantities relating to the <i>IfcBuilding</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
""../../qto/IfcProductExtension/Qto_BuildingBaseQuantities.xml""
target=""SOURCE"">Qto_BuildingBaseQuantities</a>: base quantities
for all building occurrences.</li>
</ul>

<p class=""use-head"">Spatial Structure Use Definition</p>
<p>The <i>IfcBuilding</i> is used to build the spatial structure
of a building (that serves as the primary project breakdown and
is required to be hierarchical). The spatial structure elements
are linked together by using the objectified relationship
<i>IfcRelAggregates</i>. The <i>IfcBuilding</i> references them
by its inverse relationships:</p>
<ul>
<li><i>IfcBuilding.Decomposes</i> -- referencing (<i>IfcSite</i>
|| <i>IfcBuilding</i>) by <i>IfcRelAggregates.RelatingObject</i>,
If it refers to another instance of <i>IfcBuilding</i>, the
referenced <i>IfcBuilding</i> needs to have a different and
higher <i>CompositionType</i>, i.e. COMPLEX (if the other
<i>IfcBuilding</i> has ELEMENT), or ELEMENT (if the other
<i>IfcBuilding</i> has PARTIAL).</li>
<li><i>IfcBuilding.IsDecomposedBy</i> -- referencing
(<i>IfcBuilding</i> || <i>IfcBuildingStorey</i>) by
<i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of˙<i>IfcBuilding</i>, the referenced <i>IfcBuilding</i>
needs to have a different and lower CompositionType, i.e. ELEMENT
(if the other <i>IfcBuilding</i> has COMPLEX), or PARTIAL (if the
other <i>IfcBuilding</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcBuilding</i>˙(like a curtain wall spanning
several stories), they are associated with the <i>IfcBuilding</i>
by using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>. The <i>IfcBuilding</i>
references them by its inverse relationship:</p>
<ul>
<li><i>IfcBuilding.ContainsElements</i> -- referencing any
subtype of <i>IfcProduct</i> (with the exception of other spatial
structure element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>

<p>Figure 20 shows the <i>IfcBuilding</i> as part of the spatial
structure. It also serves as the spatial container for building
and other elements.</p>
<blockquote class=""note"">NOTE Detailed requirements on mandatory element
containment and placement structure relationships are given in
view definitions and implementer agreements.</blockquote>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""Spatial structure"">
<tr><td valign=""top""><img src=
""figures/IfcBuilding-SpatialStructure.png"" alt=
""IfcBuildingStorey as part of a spatial structure"" width=""800""
height=""420"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 20 &mdash; Building composition</p></td></tr>
</table>


<p>Systems, such as building service or electrical distribution
systems, zonal systems, or structural analysis systems, relate to
<i>IfcBuilding</i> by using the objectified relationship
<i>IfcRelServicesBuildings</i>.</p>

<p class=""use-head"">Attribute Use Definition</p>

<p>Figure 21 describes the heights and elevations  of the <i>IfcBuilding</i>. It is used to provide the height above sea level of the project height datum for this building, that is, the internal height 0.00. The height 0.00 is often used as a building internal reference height and equal to the floor finish level of the ground floor.
<ul>
<li>base elevation of building provided by: <i>IfcBuilding.ElevationOfRefHeight</i>, it is usually the top of construction slab</li>
<li>base elevation of terrain at the perimeter of the building provided by: <i>IfcBuilding.ElevationOfTerrain</i>, it is usually the minimum elevation is sloped terrain</li>
<li>total height of building, also referred to as ridge height (top of roof structure, e.g the ridge against terrain): provided by BaseQuantity with Name=""TotalHeight""</li>
<li>eaves height of building (base of roof structure, e.g the eaves against terrain): provided by BaseQuantity with Name=""EavesHeight""</li>
</ul>


<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcBuilding_Heights.png"" alt=""building heights"" border=
""0"" height=""420"" width=""800"">˙</td></tr>
<tr><td><p class=""figure"">Figure 21 &mdash; Building elevations</p></td></tr>

</tbody>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcBuilding</i> is given by
the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i>, allowing multiple geometric
representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcBuilding</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if relative placement is
used) to the <i>IfcSpatialStructureElement</i> of type
<i>IfcSite</i>, or of type <i>IfcBuilding</i> (e.g. to position a
building relative to a building complex, or a building section to
a building).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'GeometricCurveSet' and a 3D 'Body' representation of type 'Brep'
is supported.</p>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcBuilding</i> is given
by either a single 2D curve (such as <i>IfcPolyline</i> or
<i>IfcCompositeCurve</i>), or by a list of 2D curves (in case of
inner boundaries), if the building has an independent geometric
representation.</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcBuilding</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body (or solid model) geometric representation (if the
building has an independent geometric representation) of
<i>IfcBuilding</i> is defined using faceted B-Rep capabilities
(with or without voids), based on the <i>IfcFacetedBrep</i> or on
the <i>IfcFacetedBrepWithVoids</i>.</p>
<p>The representation identifier and type of this representation
of <i>IfcBuilding</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Brep'</li>
</ul>
<p>Since the building shape is usually described by the exterior
building elements, an independent shape representation shall only
be given, if the building is exposed independently from its
constituting elements.</p>
</EPM-HTML>"
742;IfcBuildingStorey;"<EPM-HTML>
<p>The building storey has an
elevation and typically represents a (nearly) horizontal
aggregation of spaces that are vertically bound.</p>
<p>A storey is (if specified) associated to a building. A storey
may span over several connected storeys. Therefore storey complex
provides for a collection of storeys included in a building. A
storey can also be decomposed in (horizontical) parts, where each
part defines a partial storey. This is defihned by the composition
type attribute of the supertype
<i>IfcSpatialStructureElements</i> which is interpreted as
follow:</p>
<ul>
<li>COMPLEX = building storey complex</li>
<li>ELEMENT = building storey</li>
<li>PARTIAL = partial building storey</li>
</ul>
<blockquote class=""example"">EXAMPLE In split level houses, a storey is split into two or more partial storeys, each with a different elevation. It can be handled by defining a storey, which includes two or more partial storeys with the individual elevations.</blockquote>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0</blockquote>

<p class=""use-head"">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcBuildingStorey</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcBuildingStorey</i>
are part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcProductExtension/Pset_BuildingStoreyCommon.xml""
target=""SOURCE"">Pset_BuildingStoreyCommon</a>: common property
set for all types of building stories</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcBuildingStorey</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
""../../qto/IfcProductExtension/Qto_BuildingStoreyBaseQuantities.xml""
target=""SOURCE"">Qto_BuildingStoreyBaseQuantities</a>: base
quantities for all building storey occurrences.</li>
</ul>

<p class=""use-head"">Spatial Structure Use Definition</p>
<p>The <i>IfcBuildingStorey</i> is used to build the spatial
structure of a building (that serves as the primary project
breakdown and is required to be hierarchical). The spatial
structure elements are linked together by using the objectified
relationship <i>IfcRelAggregates</i>. The
<i>IfcBuildingStorey</i>references them by its inverse
relationships:</p>
<ul>
<li><i>IfcBuildingStorey.Decomposes</i> -- referencing
(<i>IfcBuilding</i> || <i>IfcBuildingStorey</i>) by
<i>IfcRelAggregates.RelatingObject</i>, If it refers to another
instance of˙<i>IfcBuildingStorey</i>, the referenced
<i>IfcBuildingStorey</i> needs to have a different and higher
<i>CompositionType</i>, i.e. COMPLEX (if the other
<i>IfcBuildingStorey</i> has ELEMENT), or ELEMENT (if the other
<i>IfcBuildingStorey</i> has PARTIAL).</li>
<li><i>IfcBuildingStorey.IsDecomposedBy</i> -- referencing
(<i>IfcBuildingStorey</i> || <i>IfcSpace</i>) by
<i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of˙<i>IfcBuildingStorey</i>, the referenced
<i>IfcBuildingStorey</i> needs to have a different and lower
CompositionType, i.e. ELEMENT (if the other
<i>IfcBuildingStorey</i> has COMPLEX), or PARTIAL (if the other
<i>IfcBuildingStorey</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcBuildingStorey</i> (like most building
elements, such as walls, columns, etc.), they are associated with
the <i>IfcBuildingStorey</i> by using the objectified
relationship <i>IfcRelContainedInSpatialStructure</i>. The
<i>IfcBuildingStorey</i> references them by its inverse
relationship:</p>
<ul>
<li><i>IfcBuildingStorey.ContainsElements</i> -- referencing any
subtype of <i>IfcProduct</i> (with the exception of other spatial
structure element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>

<p>Figure 25 shows the <i>IfcBuildingStorey</i> as part of the
spatial structure. It also serves as the spatial container for
building and other elements.</p>
<blockquote class=""note"">NOTE Detailed requirements on mandatory element
containment and placement structure relationships are given in
view definitions and implementer agreements.</blockquote>

<table summary=""Spatial structure"">
<tr><td valign=""top""><img src=
""figures/IfcBuildingStorey-SpatialStructure.png"" alt=
""IfcBuildingStorey as part of a spatial structure"" width=""800""
height=""420"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 25 &mdash; Building storey composition</p></td></tr>
</table>

<p>Elements can also be referenced in an
<i>IfcBuildingStorey</i>, for example, if they span through several
storeys. This is expressed by using the objectified relationship
<i>IfcRelReferencedInSpatialStructure</i>. Systems, such as
building service or electrical distribution systems, zonal
systems, or structural analysis systems, relate to
<i>IfcBuildingStorey</i> by using the objectified relationship
<i>IfcRelServicesBuildings</i>.</p>

<p class=""use-head"">Attribute Use Definition</p>

<p>Figure 26 describes the heights and elevations of the <i>IfcBuildingStorey</i>.
<ul>
<li>elevation of storey provided by: <i>IfcBuildingStorey.Elevation</i> as a local height value
relative to <i>IfcBuilding.ElevationOfRefHeight</i>, it is usually the top of construction slab</li>
<li>net height of storey, also referred to as total height or system height (top of construction slab to top of construction slab above): provided by BaseQuantity with Name=""GrossHeight""</li>
<li>net height of storey (top of construction slab to bottom of construction slab above): provided by BaseQuantity with Name=""NetHeight""</li>
</ul>

<table summary=""attributes"" cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr>
<td align=""left"" valign=""top""><img src=
""figures/IfcBuildingStorey_Heights.png"" alt=""space heights""
border=""0"" height=""400"" width=""450""></td>
<td align=""left"" valign=""top""></td></tr>
<tr><td><p class=""figure"">Figure 26 &mdash; Building storey elevations</p></td></tr>
</tbody>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcBuildingStorey</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i>, allowing multiple geometric
representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcBuildingStorey</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if relative placement is
used) to the <i>IfcSpatialStructureElement</i> of type
<i>IfcBuilding</i>, or of type <i>IfcBuildingStorey</i> (e.g. to
position a building storey relative to a building storey complex,
or a partial building storey to a building storey).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><u>Geometric Representations</u></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'GeometricCurveSet' and a 3D 'Body' representation of type 'Brep'
is supported.</p>
<blockquote>
<p><small>NOTE The independent geometric representation of
<i>IfcBuildingStorey</i> may not be required or allowed in
certain view definitions. In those cases only the contained
elements and spaces have an independent geometric
representation.</small></p>
</blockquote>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcBuildingStorey</i> is
given by either a single 2D curve (such as <i>IfcPolyline</i> or
<i>IfcCompositeCurve</i>), or by a list of 2D curves (in case of
inner boundaries), if the building storey has an independent
geometric representation.</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcBuildingStorey</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body (or solid model) geometric representation (if the
building storey has an independent geometric representation) of
<i>IfcBuildingStorey</i> is defined using faceted B-Rep
capabilities (with or without voids), based on the
<i>IfcFacetedBrep</i> or on the
<i>IfcFacetedBrepWithVoids</i>.</p>
<p>The representation identifier and type of this representation
of <i>IfcBuildingStorey</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Brep'</li>
</ul>
<p>Since the building storey shape is usually described by the
exterior building elements, an independent shape representation
shall only be given, if the building storey is exposed
independently from its constituting elements.</p>

</EPM-HTML>"
744;IfcSite;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Area where construction
works are undertaken.</p>
<p>A site is a defined area of land, possibly
covered with water, on which the project construction is to be
completed. A site may be used to erect building(s) or other AEC
products.</p>
<p>A site (<i>IfcSite</i>) may include a definition of the single
geographic reference point for this site (global position using
WGS84 with <i>Longitude</i>, <i>Latitude</i> and <i>Elevation</i>).
The precision is provided up to millionth of a second and it
provides an absolute placement in relation to the real world as
used in exchange with geospational information systems. If
asserted, the <i>Longitude</i>, <i>Latitude</i> and
<i>Elevation</i> establish the point in WGS84 where the point
0.,0.,0. of the <i>LocalPlacement</i> of <i>IfcSite</i> is
situated.</p>
<p>The geometrical placement of the site, defined by the
<i>IfcLocalPlacement</i>, shall be always relative to the spatial
structure element, in which this site is included, or absolute,
i.e. to the world coordinate system, as established by the
geometric representation context of the project. The world
coordinate system, established at the
<i>IfcProject.RepresentationContexts</i>, may include a definition
of the true north within the XY plane of the world coordinate
system, if provided, it can be obtained at
<i>IfcGeometricRepresentationContext.TrueNorth</i>.</p>
<p>A project may span over several connected or disconnected sites.
Therefore site complex provides for a collection of sites included
in a project. A site can also be decomposed in parts, where each
part defines a site section. This is defined by the composition
type attribute of the supertype <i>IfcSpatialStructureElements</i>
which is interpreted as follow:</p>
<ul>
<li>COMPLEX = site complex</li>
<li>ELEMENT = site</li>
<li>PARTIAL = site section</li>
</ul>
<blockquote class=""history"">HISTORY &nbsp;New entity in IFC Release 1.0.</blockquote>

<p class=""use-head"">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcSite</i> are defined by
the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcSite</i> are part of this IFC
release:</p>
<ul>
<li><a href=""../../psd/IfcProductExtension/Pset_SiteCommon.xml""
target=""SOURCE"">Pset_SiteCommon</a>: common property set for all
types of site</li>
</ul>

<p class=""use-head"">Quantity Use Definition</p>
<p>The quantities relating to the <i>IfcSite</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
""../../qto/IfcProductExtension/Qto_SiteBaseQuantities.xml"" target=
""SOURCE"">Qto_SiteBaseQuantities</a>: base quantities for all site
occurrences.</li>
</ul>

<p class=""use-head"">Spatial Structure Use Definition</p>
<p>The <i>IfcSite</i> is used to build the spatial structure of a
building (that serves as the primary project breakdown and is
required to be hierarchical). The spatial structure elements are
linked together by using the objectified relationship
<i>IfcRelAggregates</i>. The <i>IfcSite</i> references them by its
inverse relationships:</p>
<ul>
<li><i>IfcSite.Decomposes</i> -- referencing (<i>IfcProject</i> ||
<i>IfcSite</i>) by <i>IfcRelAggregates.RelatingObject</i>, If it
refers to another instance of <i>IfcSite</i>, the referenced
<i>IfcSite</i> needs to have a different and higher
<i>CompositionType</i>, i.e. COMPLEX (if the other <i>IfcSite</i>
has ELEMENT), or ELEMENT (if the other <i>IfcSite</i> has
PARTIAL).</li>
<li><i>IfcSite.IsDecomposedBy</i> -- referencing (<i>IfcSite</i> ||
<i>IfcBuilding</i> || <i>IfcSpace</i>) by
<i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of <i>IfcSite</i>, the referenced <i>IfcSite</i> needs to
have a different and lower CompositionType, i.e. ELEMENT (if the
other <i>IfcSite</i> has COMPLEX), or PARTIAL (if the other
<i>IfcSite</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcSite</i> (like a fence, or a shear wall), they
are associated with the <i>IfcSite</i> by using the objectified
relationship <i>IfcRelContainedInSpatialStructure</i>. The
<i>IfcIfcSite</i> references them by its inverse relationship:</p>
<ul>
<li><i>IfcSite.ContainsElements</i> -- referencing any subtype of
<i>IfcProduct</i> (with the exception of other spatial structure
element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>

<p>Figure 51 shows the <i>IfcSite</i> as part of the spatial structure. In addition to the logical spatial structure, also the placement hierarchy is shown. In this example the spatial structure hierarchy and the placement hierarchy are identical.</p>
<blockquote class=""note"">NOTE Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.</blockquote>

<table summary=""Spatial and placement structure"">
<tr><td valign=""top""><img src=""figures/IfcSite-SpatialStructure.png"" alt=""IfcSite as part of a spatial structure"" width=""800"" height=""420"" border=""0""></tr>
<tr><td><p class=""figure"">Figure 51 &mdash; Site composition</p></td></tr>
</table>

<p class=""use-head"">Attribute Use Definition</p>
<p>Figure 52 describes the heights and elevations of the <i>IfcSite</i>. It is used to provide the geographic longitude, latitude, and height above sea level for the origin of the site. The origin of the site is the local placement.</p>
<p>The provision of longitude, latitude, height at the <i>IfcSite</i> for georeferencing is provided for upward compatibility reasons. It requires a single instance of <i>IfcSite</i> and WGS84 as coordinate reference system.</p>
<P>For exact georeferencing the new entities <i>IfcCoordinateReferenceSystem</i> and <i>IfcMapConversion</i> should be used.</p>
<ul>
<li><small>reference height of site is provided by: <i>IfcSite.RefElevation</i>, it is given according to the height datum used at this location.</small></li>
<li><small>the reference height of each building situated at the site is given againt the same height datum used at this location.</small></li>
<li><small>the elevations of each storey belonging to each building are given as local height relative to the reference height of the building.</small></li>
</ul>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=
""attribute use"">
<tbody>
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcSite_Heights.png"" alt=""building heights"" border=""0"" height=""400"" width=""500"">&nbsp;</td></tr>
<tr><td><p class=""figure"">Figure 52 &mdash; Site elevations</p></td></tr>
</tbody>
</table>

<p class=""use-head"">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcSite</i> is given by the
<i>IfcProductDefinitionShape</i> and <i>IfcLocalPlacement</i>
allowing multiple geometric representations.</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcSite</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the
<i>IfcSpatialStructureElement</i> of type ""<i>IfcSite</i>"", if
relative placement is used (e.g. to position a site relative a a
site complex, or a site section to a site).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system. If there is only one
site object, then this is the default situation.</li>
</ul>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcSite</i> is given by
either a single 2D curve (such as <i>IfcPolyline</i> or
<i>IfcCompositeCurve</i>), or by a list of 2D curves (in case of
inner boundaries).</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcSite</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet', or 'Annotation2D'</li>
</ul>
<p><b>Survey Points Representation</b></p>
<p>The survey point representation of <i>IfcSite</i> is defined
using a set of survey points and optionally breaklines. The
breaklines are restricted to only connect points given in the set
of survey points. Breaklines, if given, are used to constrain the
triangulation.</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcSite</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'SurveyPoints'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>

<p>Figure 53 shows a set of survey points, given as 3D Cartesian points within the object coordinate system of the site.  Figure 54 shows the result after facetation.</p>
<p>The set of <i>IfcCartesianPoint</i> is included in the set of <i>IfcGeometricCurveSet.Elements</i>.</p>

<table cellpadding=""2"" cellspacing=""2"" summary=""survey points representation"">
<tr>
<td><img src=""figures/IfcSite-Standard-points.gif"" alt=""points only"" border=""0"" height=""300"" width=""400""></td>
<td><img src=""figures/IfcSite-Standard-facets-points.gif"" alt=""facetation of points"" border=""0"" height=""300"" width=""400""></td>
</tr>
<tr>
<td width=""400""><p class=""figure"">Figure 53 &mdash; Site survey points</p></td>
<td width=""400""><p class=""figure"">Figure 54 &mdash; Site survey points facetation</p></td>
</tr>
</table>

<p>Figure 55 shows A set of survey points, given as 3D Cartesian points, and a set of break points, given as a set of lines, connecting some survey points, within the object coordinate system of the site.  Figure 56 shows the result after facetation.</p>
<p>The set of <i>IfcCartesianPoint</i> and the set of <i>IfcPolyline</i> are included in the set of <i>IfcGeometricCurveSet.Elements</i>.</p>

<table cellpadding=""2"" cellspacing=""2"" summary=""survey points representation"">
<tr>
<td><img src=""figures/IfcSite-Standard-breaklines.gif"" alt=""breaklines"" border=""0"" height=""300"" width=""400""></td>
<td><img src=""figures/IfcSite-Standard-facets-breaklines.gif"" alt=""facetation with breakpoints"" border=""0"" height=""300"" width=
""400""></td>
</tr>
<tr>
<td width=""400""><p class=""figure"">Figure 55 &mdash; Site breaklines</p></td>
<td width=""400""><p class=""figure"">Figure 56 &mdash; Site breaklines facetation</p></td>
</tr>
</table>

<blockquote class=""note"">NOTE&nbsp; The geometric representation of the site has been based on the ARM level description of the site_shape_representation given within the ISO 10303-225 ""Building Elements using explicit shape representation"".</blockquote>

<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcSite</i> is defined using a
solid or surface model. Applicable solids are the
<i>IfcFacetedBrep</i> or on the <i>IfcFacetedBrepWithVoids</i>,
applicable surface models are the <i>IfcFaceBasedSurfaceModel</i>
and the <i>IfcShellBasedSurfaceModel</i>.</p>
<p>The representation identifier and type of this representation of
<i>IfcSite</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> = 'Brep', or
'SurfaceModel'</li>
</ul>
</EPM-HTML>"
765;IfcElementQuantity;"<EPM-HTML>
<p><u>Definition from IAI</u>: An <i>IfcElementQuantity</i>
defines a set of derived measures of an element's physical
property. Elements could be spatial structure elements (like
buildings, storeys, or spaces) or building elements (like walls,
slabs, finishes). The <i>IfcElementQuantity</i> gets assigned to
the element by using the <i>IfcRelDefinesByProperties</i>
relationship.</p>
<p>The optional <i>MethodOfMeasurement</i> attribute defines the
code, e.g. from a standard method of measurement, which had been
used to calculate the element quantity.</p>
<blockquote>
<p><small>NOTE The recognizable values for the name and the
method of measurement attributes have to be agreed upon in
further agreement documents, such as implementers agreements.
Some of these agreements might be limited to a certain region, to
which the method of measurement applies.</small></p>
</blockquote>
<p>The name attribute, given at the individual <i>Quantities</i>
provides a recognizable semantic meaning of the element quantity.
Both information is needed to establish a precise meaning for the
measure value. An optional description may be assigned to each of
the <i>Quantities</i>. All quantities assigned by a single
instance of <i>IfcElementQuantity</i> are deemed to have been
generated according to the same method of measurement. However
several instances of <i>IfcElementQuantity</i> are assignable to
an element, thus allowing for an element having quantities
generated according to several methods of measurement.</p>
<blockquote>
<p><small>EXAMPLE1 To exchange the net floor area of spaces in
the German region (as <i>IfcSpace</i>), the name might be
'Netto-Grundfl&auml;che' (net floor area), and the method of
measurement might be accordingly 'DIN277-2' (German industry norm
no. 277 edition 2)</small></p>
</blockquote>
<blockquote>
<p><small>EXAMPLE2 The same instance of <i>IfcSpace</i> may have
a different area measure assigned in the German region according
to a housing regulation, the name would be 'Wohnfl&auml;che' and
the method of measurement would be '2.BV'. It would be attached
to the <i>IfcSpace</i> by a separate
<i>IfcRelDefinesByProperties</i> relationship.</small></p>
</blockquote>
<p>The <i>IfcElementQuantity</i> can have the following subtypes
of <i>IfcPhysicalQuantity</i> within its SET of
<i>Quantities</i>, which count for the basis measure types
used:</p>
<ul>
<li>count measure</li>
<li>weight measure</li>
<li>length measure</li>
<li>area measure</li>
<li>volume measure</li>
<li>time measure</li>
</ul>
<blockquote>
<p><small><font color=""#0000FF"">HISTORY New entity in IFC Release
2x. NOTE: It replaces the calcXxx attributes used in previous IFC
Releases.</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE Subtyped from new
intermediate <i>IfcPreDefinedPropertySet</i>
supertype.</font></small></p>
</blockquote>
<p><b><u>Quantity Use Defintion</u></b></p>
<p>Base quantities are quantity definitions that are independent
of a particular method of measurement and therefore
internationally applicable. Base quantities are defined as gross
and net values and provided by measurement of the correct
geometric shape representation of the element. The IFC
specification includes a set of base quantity definition. See
each subtype of <i>IfcElement</i> for applicable base
quantities.</p>
<p>The following general agreements apply for each base quantity
set</p>
<ul>
<li><i>IfcElementQuantity.Name</i> = 'BaseQuantities'</li>
<li><i>IfcElementQuantity.MethodOfMeasurement</i> = NIL</li>
<li><i>IfcElementQuantity.Quantities</i> = SET of subtypes of
<i>IfcPhysicalSimpleQuantity</i> with values for the <i>Name</i>
attribute as published as part of the IFC specifciation.</li>
</ul>
</EPM-HTML>"
770;IfcRelAssociatesMaterial;"<EPM-HTML>
<p><u>Definition from IAI</u>: Objectified relationship between a
material definition and elements or element types to which this
material definition applies.</p>
<p>The material definition can be:</p>
<ul>
<li>assigned to an element occurrence as a specific usage of a
layer set or profile set</li>
<li>assigned to an element occurrence or element type as a layer
set, profile set, constituent set or a single material</li>
</ul>
<p>Materials can be arranged by layers and applied to layered
elements. Typical elements are walls and slabs.</p>
<ul>
<li>An <i>IfcMaterialLayerSet</i>, for layered elements with an
indication of the layering direction and individual layer
thicknesses</li>
<li>An <i>IfcMaterialLayerSetUsage</i>, i.e. a material layer set
with positioning information along the reference axis or surface
of the element.
<blockquote><small>NOTE As a material layer set usage is an
occurrence based information, that applies to each individual
element, it cannot be assigned to an element
type.</small></blockquote>
</li>
</ul>
<p>Material can be applied to profiles. Typical elements using
profile material are beam, column, member</p>
<ul>
<li>An <i>IfcMaterialProfileSet</i>, i.e. a set of material
assigned to a set of profiles, with a single material assigned to
a single profile as the default.</li>
<li>An <i>IfcMaterialProfileSetUsage</i>, i.e. a material profile
set with positioning information relative to the element axis,
also refered to as cardinal point.
<blockquote><small>NOTE As a material profile set usage is an
occurrence based information, that applies to each individual
element, it cannot be assigned to an element
type.</small></blockquote>
</li>
</ul>
<p>Materials can be arranged by identified parts of a component
based element. Typical elements are dorrs/windows (with
components such as lining, framing and glazing), or distribution
elements.</p>
<ul>
<li>An <i>IfcMaterialConstituentSet</i>, for component based
elements with an indication of the component by keyword to which
the material consituent applies.
<blockquote><small>NOTE See the material use definitions at each
applicable subtype of <i>IfcElement</i> or <i>IfcElementType</i>
for a provision of these keywords.</small></blockquote>
</li>
</ul>
<p>As a fallback, or in cases where only a single material
information is needed, material information can be directly
associated</p>
<ul>
<li>A single <i>IfcMaterial</i> for any element where the
material use definition does not prohibits its direct
association</li>
<li>An <i>IfcMaterialList</i>, e.g. for composite elements,
without an information, how the different materials are arranged.
<blockquote><small><font color=""#FF0000"">NOTE The use of
<i>IfcMaterialList</i> is deprecated in IFC2x4 onwards. Use
<i>IfcMaterialConstituentSet</i>
instead.</font></small></blockquote>
</li>
</ul>
<p>The <i>IfcRelAssociatesMaterial</i> relationship is a special
type of the <i>IfcRelAssociates</i> relationship. It can be
applied to subtypes of <i>IfcElement</i> and subtypes of
<i>IfcElementType</i>.</p>
<ul>
<li>The <i>IfcElement</i> has an inverse relation to its material
definition by the <i>HasAssociations</i> attribute, inherited
from <i>IfcObject</i>.</li>
<li>The <i>IfcElementType</i> has an inverse relation to its
material definition by the <i>HasAssociations</i> attribute,
inherited from <i>IfcPropertyDefinition</i>.</li>
</ul>
<p>If both, the element occurrence (by an instance of
<i>IfcElement</i>) and the element type (by an instance of
<i>IfcElementType</i>, connected through
<i>IfcRelDefinesByType</i>) have an associated material, then the
material associated to the element occurrence overrides the
material associated to the element type.</p>
<blockquote>
<p><small><font color=""#0000FF"">HISTORY New entity in IFC Release
2.x.</font></small></p>
</blockquote>
<p><u>Informal proposition</u></p>
<ol>
<li>An <i>IfcMaterialLayerSetUsage</i> shall not be associated
with a subtype of <i>IfcElementType</i>, it should only be
associated with individual occurrences</li>
<li>An <i>IfcMaterialProfileSetUsage</i> shall not be associated
with a subtype of <i>IfcElementType</i>, it should only be
associated with individual occurrences</li>
</ol>

</EPM-HTML>"
776;IfcProduct;"<EPM-HTML> 

<p>Any object that relates to a
geometric or spatial context. Subtypes of <i>IfcProduct</i>
usually hold a shape representation and a object placement within
the project structure.</p>
<p>This includes manufactured, supplied or created objects
(referred to as elements) for incorporation into an AEC/FM
project. This also includes objects that are created indirectly
by other products, as spaces are defined by bounding elements.
Products can be designated for permanent use or temporary use, an
example for the latter is formwork. Products are defined by their
properties and representations.</p>
<p>In addition to physical products (covered by the subtype
<i>IfcElement</i>) and spatial items (covered by the subtype
<i>IfcSpatialElement</i>) the <i>IfcProduct</i> also includes
non-physical items, that relate to a geometric or spatial
contexts, such as grid, port, annotation, structural actions,
etc.</p>
<p>The inherited <i>ObjectType</i> attribute can be used to
designate a particular type of the product instance. If subtypes
of <i>IfcProduct</i> have a <i>PredefinedType</i> defined, the
<i>ObjectType</i> is used to provide the user defined, particular
type of the product instance, if the <i>PredefinedType</i> is set
to <small>USERDEFINED</small>.</p>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 1.0
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>On a generic level products can be assigned to processes,
controls, resources, project by using the relationship objects
that refer to the corresponding object:</p>
<ul>
<li><b>Having a control applied</b>: assigned using
<i>IfcRelAssignsToControl</i> linking the <i>IfcProduct</i> to an
<i>IfcControl</i>
<ul>
<li style=""list-style-type:none""><small>An example of this
relationship is the assignment of a performance history to a
distribution element.</small></li>
</ul>
</li>
<li><b>Being assigned to a process</b>: assigned using
<i>IfcRelAssignsToProcess</i> linking the <i>IfcProduct</i> to an
<i>IfcProcess</i>
<ul>
<li style=""list-style-type:none""><small>An example of this
relationship is the assignment of products like wall, slab,
column to a contruction task for construction
planning.</small></li>
</ul>
</li>
<li><b>Being assigned to a resource</b>: assigned using
<i>IfcRelAssignsToResource</i> linking the <i>IfcProduct</i> to
an <i>IfcResource</i>
<ul>
<li style=""list-style-type:none""><small>An example of this
relationship is the assignment of products to a construction
resource that consumes the product.</small></li>
</ul>
</li>
</ul>
<p class=""use-head"">Type use definition</p>
<p>Any instance of <i>IfcProduct</i> defines a particular
occurrence of a product, the common type information, that
relates to many similar (or identical) occurrences of
<i>IfcProduct</i>, is handled by the <i>IfcTypeProduct</i> (and
its subtypes), assigned to one or many occurrences of
<i>IfcProduct</i> by using the objectified relationship
<i>IfcRelDefinesByType</i>. The <i>IfcTypeProduct</i> may
provide, in addition to common properties, also a common
geometric representation for all occurrences.</p>
<blockquote><small>See <i>IfcTypeProduct</i> for how to use a
common geometric representation and <i>IfcRelDefinesByType</i>
for using and overriding common properties.</small></blockquote>

<p class=""use-head"">Representation use definition</p>
<p>An <i>IfcProduct</i> occurs at a specific location in space if
it has a geometric representation assigned. It can be placed
relatively to other products, but ultimately relative to the
world coordinate system defined for this project. The
<i>ObjectPlacement</i> attribute establishes the coordinate
system in which all points and directions used by the geometric
representation items under <small>Representation</small> are
founded. The placement can either be:</p>
<ul>
<li><b>a relative placement</b>: by <i>IfcLocalPlacement</i> with
<i>PlacementRelTo</i> pointing to a parent placement</li>
<li><b>an absolute placement</b>: by <i>IfcLocalPlacement</i>
with <i>PlacementRelTo</i> being NIL</li>
<li><b>a placement relative to a grid</b>: by
<i>IfcGridPlacement</i></li>
</ul>
<p>The <i>Representation</i> is provided by an
<i>IfcProductDefinitionShape</i> being either a geometric shape
representation, or a topology representation (with or without
underlying geometry of the topological items).</p>

</EPM-HTML>"
782;IfcObject;"<EPM-HTML> 

<p>An <i>IfcObject</i> is the
generalization of any semantically treated thing or process.
Objects are things as they appear - i.e. occurrences.</p>
<blockquote><small>NOTE Examples of <i>IfcObject</i> include
physically tangible items, such as wall, beam or covering,
physically existing items, such as spaces, or conceptual items,
such as grids or virtual boundaries. It also stands for
processes, such as work tasks, for controls, such as cost items,
for actors, such as persons involved in the design process,
etc.</small></blockquote>
<p>Objects can be named, using the inherited <i>Name</i>
attribute, which should be a user recognizable label for the
object occurrance. Further explanations to the object can be
given using the inherited <i>Description</i> attribute. The
<i>ObjectType</i> attribute is used:</p>
<ul>
<li>to store the user defined value for all subtypes of
<i>IfcObject</i>, where a <i>PredefinedType</i> attribute is
given, and its value is set to USERDEFINED.</li>
<li>to provide a type information (could be seen as a very
lightweight classifier) of the subtype of <i>IfcObject</i>, if no
<i>PredefinedType</i> attribute is given. This is often the case,
if no comprehensive list of predefined types is available.</li>
</ul>
<p>Objects are independent pieces of information that might
contain or reference other pieces of information. There are
several relationships in which objects can be involved:</p>
<ul>
<li><b>Association to external/internal resource information</b>
- an association relationship that refers to external/internal
sources of information. See supertype <i>IfcObjectDefinition</i>
for more information.</li>
<li><b>Assignment of other objects</b> - an assignment
relationship that refers to other types of objects. See supertype
<i>IfcObjectDefinition</i> for more information.</li>
<li><b>Aggregation of other objects</b> - an aggregation
relationship that establishes a whole/part relation. Objects can
either be a whole, or a part, or both. See supertype
<i>IfcObjectDefinition</i> for more information.<br>
<br></li>
<li><b>Assignment of a type</b> : <i>IsTypedBy</i> - a definition
relationship <i>IfcRelDefinesByType</i> that uses a type
definition to define the common characteristics of this
occurrences, potentially including the common shape
representation and common properties of all object occurrences
assigned to this type. It is a specific - occurrence relationship
with implied dependencies (as the occurrence properties depend on
the properties of the type, but may override them).</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE See <i>IfcRelDefinesByType</i> for an
explanatory figure. Also see for how to override type properties
by occurrence properties</small></blockquote>
</li>
<li><b>Assignment of a partial type</b> : <i>IsDeclaredBy</i>,
<i>Declares</i> - a definition relationship
<i>IfcRelDefinesByObject</i> that uses a component of a type
definition (a part of a type, called the ""declaring part"") to
define a component of an occurence (part of occurrence, called
the ""reflected part""). This is also refered to as a ""deep copy"".
The common characteristics of all parts in the occurrence are
defined by parts in the type. It is a specific - occurrence
relationship with implied dependencies (as the occurrence
properties depend on the properties of the type, but may override
them).<br></li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE See <i>IfcRelDefinesByObject</i> for an
explanatory figure.</small></blockquote>
</li>
<li><b>Assignment of property sets</b> : <i>IsDefinedBy</i> - a
definition relationship <i>IfcRelDefinesByProperties</i> that
assignes property set definitions to the object occurrence.</li>
</ul>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 1.0
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The inverse relationships <i>Declares</i>, <i>IsDeclaredBy</i>, and <i>IsTypedBy</i> have been added, types are not longer included in the <i>IsDefinesBy</i> relationship. <i>IfcProject</i> has been promoted to be a subtype of <i>IfcObjectDefinition</i> -&gt; <i>IfcContext</i>.
</blockquote>

<p><u>Informal Proposition</u></p>
<ol>
<li>A partial type assignment, i.e. the inverse attribute
<i>IsDeclaredBy</i>, or <i>Declares</i> shall only be used, if
the object is part of a decomposition, i.e. if either
<i>IsDecomposedBy</i>, or <i>Decomposes</i> is exerted.</li>
</ol>

</EPM-HTML>"
794;IfcObjectDefinition;"<EPM-HTML>

<p>An <em>IfcObjectDefinition</em> is the generalization of any
semantically treated thing or process, either being a type or an
occurrences. Object defintions can be named, using the inherited
<em>Name</em> attribute, which should be a user recognizable label
for the object occurrance. Further explanations to the object can
be given using the inherited <em>Description</em> attribute. A
context is a specific kind of object definition as it provides the
project or library context in which object types and object
occurrences are defined.</p>
<p>Objects are independent pieces of information that might contain
or reference other pieces of information. There are four essential
kinds of relationships in which object definitons (by their
instantiable subtypes) can be involved:</p>
<ul>
<li><b>Assignment of other objects</b> - an assignment relationship
(<em>IfcRelAssigns</em>) that refers to other types of objects and
creates a bi-directional association. The semantic of the
assignment is established at the level of the subtypes of the
general <em>IfcRelAssigns</em> relationship. There is no dependency
implied a priori by the assignment.</li>
<li><b>Association to external resources</b> - an association
relationship (<em>IfcRelAssociates</em>) that refers to external
sources of information (most notably a classification or document)
and creates a uni-directional association. There is no dependency
implied by the association.</li>
<li><b>Aggregation of other objects</b> - an aggregation
relationship (<em>IfcRelAggregates</em>) that establishes an
unordered, spatial whole/part relation and creates a bi-directional
relation. There is an implied dependency established.</li>
<li><b>Nesting of other objects</b> - a nesting relationship
(<em>IfcRelNests</em>) that establishes an ordered, non-spatial
whole/part relation and creates a bi-directional relation. There is
an implied dependency established.</li>
<li><b>Declaration within a context</b> - a relationship
(<em>IfcRelDeclares</em>) of the uppermost object definition within
the object definition tree (e.g. the summary object within an
object nesting tree) to the context (a project or project library).
It applies the units, representation context and other context
information to this object definition and all dependent ones.
<ul>
<li style=""list-type-type:none""><small>EXCEPTION&nbsp; The link
between the uppermost object in the spatial structure tree, that is
<em>IfcSite</em> or <em>ifcBuilding</em>, and the context provided
by <em>IfcProject</em> is created using the
<em>IfcRelAggregates</em> relationship. See <em>IfcProject</em> for
more information.</small></li>
</ul>
</li>
</ul>

<blockquote class=""history"">
HISTORY New abstract entity in IFC2x3.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The new subtype <em>IfcContext</em> and the relationship to context <em>HasContext</em> has been added . The decomposition relationship is split into ordered nesting (<em>Nests</em>, <em>IsNestedBy</em>) and un-ordered aggregating (<em>Decomposes</em>, <em>IsDecomposedBy</em>).
</blockquote>

</EPM-HTML>"
805;IfcRoot;"<EPM-HTML> 

<p><i>IfcRoot</i> is the most abstract and root class for all IFC entity definitions that roots in the kernel or in subsequent layers of the IFC object model. It is therefore the common supertype of all IFC entities, beside those defined in an IFC resource schema. All entities that are subtypes of <i>IfcRoot</i> can be used independently, whereas resource schema entities, that are not subtypes of <i>IfcRoot</i>, are not supposed to be independent entities.</p>

<p><i>IfcRoot</i> assigns the globally unique ID, and the ownership and history information to the entity. In addition it may provide for a name and a description about the concept.</p>

<blockquote class=""note"">
NOTE View definitions and implementation agreement may impose additional restrictions on the use of the <i>OwnerHistory</i> to handle object versioning.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attribute <i>OwnerHistory</i> has been made OPTIONAL.
</blockquote>

</EPM-HTML>"
815;IfcPropertyDefinition;"<EPM-HTML> 

<p><em>IfcPropertyDefinition</em> defines the generalization of
all characteristics (i.e. a grouping of individual properties),
that may be assigned to objects. Currently, subtypes of
<i>IfcPropertyDefinition</i> include property set occurrences,
property set templates, and property templates.</p>
<blockquote>
<p><strong>Property set template</strong> -
<em>IfcPropertySetTemplate</em>, a collection of property templates
that determine the definition of properties used within a project
context.</p>
<p><strong>Property template</strong> -
<em>IfcPropertyTemplate</em>, a single template that determines the
definition of a particular property used in the same project
context. The template may determine the name, description, data
type, the unit, or a standard expression for each property that is
based on that template.</p>
<p><strong>Property set occurrence</strong> -
<em>IfcPropertySet</em>, a set of individual properties (that may
or may not be determined by a property template) holding individual
values, measure types and units, and are associated to an object
occurrence or object type.</p>
</blockquote>

<blockquote class=""note"">
NOTE 1&nbsp; The subtype hierarchy of <em>IfcPropertyDefinition</em> also includes statically defined property sets as <em>IfcPreDefinedPropertySet</em>. Those are rarely used collections of fixed attributes combined in an entity definition. The <em>IfcPreDefinedPropertySet</em> can not be determined by an <em>IfcPropertySetTemplate</em>.
</blockquote>

<blockquote class=""note"">
NOTE 2&nbsp; Individual properties, (subtypes of <em>IfcProperty</em>), are currently not included in the subtype hierarchy of <em>IfcPropertyDefinition</em>. This anomaly is due to upward compatibility reasons with earlier releases of this
standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2.0
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Property definitions define information that is shared among
multiple instances of objects, either object occurrences or object
types. <em>IfcPropertyDefinition</em>'s (by their instantiable
subtypes) can participated within the following relationships:</p>
<ul>
<li><strong>Assignment to a project context</strong> - an
<em>HasContext</em> relationship to <em>IfcRelDeclares</em> that
establishes the project context in which this property definition
is declared. This relationship is predominately applicable to
subtypes of <em>IfcPropertyTemplateDefinition</em>.</li>
<li><strong>Association to external resources</strong> - an
<em>HasAssociation</em> relationship to <em>IfcRelAssociates</em>
that refers to external sources of information (most notably a
classification or document) and creates a uni-directional
association. There is no dependency implied by the
association.</li>
</ul>
<p>Subtypes are included in more specific relationships, see
<em>IfcPropertySetDefinition</em> and
<em>IfcPropertyTemplateDefinition</em> for details.</p>

</EPM-HTML>"
820;IfcPropertySetDefinition;"<EPM-HTML> 

<p><em>IfcPropertySetDefinition</em> is a generalization of all
individual property sets that can be assigned to an object or type
object. The property set definition can be either:</p>
<blockquote>
<p><strong>Dynamically extendable property sets</strong> -
<em>IfcPropertySet</em>, a set of properties for which the IFC
model only provides a kind of ""meta model"", to be further declared
by agreement. This means no entity definition of the properties
exists within the IFC model. The declaration is done by assigning a
significant string value to the <em>Name</em> attribute of the
entity as defined in the entity <em>IfcPropertySet</em> and at each
subtype of <em>IfcProperty</em>, referenced by the property set.
Dynamically defined property sets may have an underlying template
provided by <em>IfcPropertySetTemplate</em>.</p>
<p><strong>Statically defined property sets</strong> -
<em>IfcPreDefinedPropertySet</em>, a property set entity that
exists within the IFC specification. The semantic meaning of each
statically defined property set is declared by its entity type and
the meaning of the properties is defined by the name and data type
of the explicit attribute representing it.</p>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2x
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The subtype <em>IfcPreDefinedPropertySet</em> has been added.
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Property set definitions define information that is shared among
multiple instances of objects, either object occurrences or object
types. <em>IfcPropertySetDefinition</em>'s (by their instantiable
subtypes) can participated within the following relationships:</p>
<ul>
<li><strong>Assignment to object types</strong> - an
<em>DefinesType</em> direct relationship to <em>IfcTypeObject</em>
that applies the property set, with all included properties, to the
object type. Those properties apply to all object occurrences
having the same object type.</li>
<li><strong>Assignment to object occurrences</strong> - an
<em>DefinesOccurrence</em> relationship to
<em>IfcRelDefinesByProperties</em> that applies the property set,
with all included properties, to the object occurrence.</li>
</ul>

<blockquote class=""note"">
NOTE&nbsp; Properties assigned to object occurrences may override properties assigned to the object type. See <em>IfcRelDefinesByType</em> for further information.
</blockquote>

</EPM-HTML>"
825;IfcPropertySet;"<EPM-HTML> 

<p><em>IfcPropertySet</em> defines all dynamically extensible
properties. The property set is a container class that holds
properties within a property tree. These properties are interpreted
according to their name attribute.</p>
<p>The same <em>IfcPropertySet</em> can be assignd to multiple
object occurrences, it should then be assigned by a single instance
of <em>IfcRelDefinedByProperties</em> to a set of related objects.
Those property sets are referred to as shared property sets. It can
also be assigned to an object type.</p>
<p>The underlying structure, i.e. the required name, the applicable
object or object types to which the property set can be attached
and the individual properties that maybe included can be assigned
using the property set template.</p>

<blockquote class=""note"">
NOTE&nbsp; See <em>IfcRelDefinesByType</em> for how to override property sets assigned to an object type within the object occurrence.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 1.0
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; All statically defined property set entities are no longer subtypes of
<em>IfcPropertySet</em>.
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Property sets are related to other objects by using the
relationship object that refers to the corresponding object:</p>
<ul>
<li><b>Occurrence Object</b>: <em>IfcRelDefinesByProperties</em>
using the inverse attribute <em>DefinesOccurrence</em>.</li>
<li><b>Type Object</b>: using a direct link by inverse attribute
<em>DefinesType</em>.</li>
<li><b>External reference</b>: subtypes of
<em>IfcRelAssociates</em> are used to provide a link to a
classification system, or external library providing further
reference to the property set. Accessible by inverse attribute
<em>HasAssociations</em>.</li>
<li><b>Underlying template</b>: <em>IfcRelDefinesByTemplate</em>
using the inverse attribute <em>IsDefinedBy</em>.</li>
</ul>

<p class=""use-head"">Attribute use definition</p>
<p>Instances of <em>IfcPropertySet</em> are used to assign named
sets of individual properties (complex or single properties). Each
individual property has a significant name string. Some property
sets are included in the IFC specification and have&nbsp;a
predefined set of properties indicated by assigning a significant
name. These property sets are listed under ""property sets"" main
menu item within this specification and from the object
documentation sheet for those object to which they are applicable.
The naming convention ""Pset_Xxx"" applies to all those property sets
that are defined as part of the IFC specification and it shall be
used as the value of the <em>Name</em> attribute.</p>
<p>In addition any user defined property set can be captured.
Property sets that are not declared as part of the IFC
specification shall have a <em>Name</em> value not including the
""Pset_"" prefix.</p>

</EPM-HTML>"
830;IfcRelDefinesByTemplate;"<EPM-HTML>

<p>The objectified relationship
<i>IfcRelDefinesByTemplate</i> defines the relationships between
property set template and property sets. Common information about
property sets, e.g. the applicable name, description, contained
properties, is defined by the property set template and assigned
to all property sets.</p>
<p>The <i>IfcRelDefinesByTemplate</i> is a 1-to-N relationship,
as it allows for the assignment of one property set template to a
single or to many property sets. Those property sets then share
the same property set template definition.</p>

<blockquote class=""history"">
HISTORY New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
833;IfcRelDefines;"<EPM-HTML>

<p>A generic and abstract relationship which subtypes are used to:</p>
<ul>
<li>assign a object type to an object occurrence</li>
<li>assign a property set to an object instance</li>
<li>assign a property set template to a property set</li>
</ul>
<blockquote><small>EXAMPLE ˙Several instances of windows within
the IFC project model may be of the same (catalogue or
manufacturer) type. Thereby they share the same properties. This
relationship is established by the subtype
<i>IfcRelDefinesByType</i> of <i>IfcRelDefines</i> relationship
assigning an <i>IfcWindowStyle</i> to multiple occurrences
<i>IfcWindow</i>.<br>
<br>
EXAMPLE ˙The (same) property set, e.g.˙
Pset_ProductManufacturerInfo, keeping the manufacturer name,
label and production year of a product, can be assigned to one,
or many instances of furnishing. This relationship is established
by the subtype <i>IfcRelDefinesByProperties</i> of
<i>IfcRelDefines</i> relationship assigning an
<i>IfcPropertySet</i> to one or more instances of
<i>IfcFurnishingElement</i>.</small></blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attribute <i>RelatedObjects</i> had been demoted to the subtypes <i>IfcRelDefinesByProperties</i> and
<i>IfcRelDefinesByType</i>.
</blockquote>

</EPM-HTML>"
838;IfcRelationship;"<EPM-HTML> 

<p><i>IfcRelationship</i> is the abstract generalization of all objectified relationships in IFC. Objectified relationships are the preferred way to handle relationships among objects. This allows to keep relationship specific properties directly at the relationship and opens the possibility to later handle relationship specific behavior. </p> 

<p>There are two different types of relationships, 1-to-1 relationships and 1-to-many relationship. used within the subtypes of <i>IfcRelationship</i>. The following convention applies to all subtypes:</p> 

<ul> 
<li>The two sides of the objectified relationship are named <br>- Relating+&lt;name of relating object&gt; and <br>- Related+&lt;name of related object&gt;</li> 
<li>In case of the 1-to-many relationship, the related side of the relationship shall be an aggregate SET 1:N</li> 
</ul> 

<blockquote class=""history""> 
HISTORY: New entity in IFC Release 1.0.
</blockquote>

</EPM-HTML>"
845;IfcRelAssigns;"<EPM-HTML>

<p>The assignment relationship, <i>IfcRelAssigns</i>, is a generalization of ""link"" relationships among instances of <i>IfcObject</i> and its various 1<sup>st</sup> level subtypes. A link denotes the specific association through which one object (the client) applies the services of other objects (the suppliers), or through which one object may navigate to other objects.</p>

<p>The client is denoted as the relating object and is established at the level of the specific, instantiable subtypes of <i>IfcRelAssigns</i>. The suppliers are denoted as the related objects and they are established by the <i>RelatedObjects</i> attribute.</p> 
	 
<blockquote class=""note"">
NOTE: The terms ""client"" and ""supplier"" are used in a general concept and do not imply any meaning for implementations of systems (like client-server).
</blockquote>

<blockquote class=""example"">
EXAMPLE: A resource may receive information about its nature of representing real building products by establishing a link between <i>IfcResource</i> and <i>IfcBuildingElement</i> (subtype of <i>IfcProduct</i>) through the assignment relationship <i>IfcRelAssignsToResource</i>. The resource is then the client that applies the services of other objects (here building elements) to express the particular view of elements to be consumed as a resource in a process.
</blockquote>

<p>The assignment relationship establishs a bi-directional relationship among the participating objects and does not imply any dependency. The subtypes of <i>IfcRelAssigns</i> establishes the particular semantic meaning of the assignment relationship.</p>

<blockquote class=""history""> 
HISTORY: New entity in IFC Release 2x.
</blockquote> 

</EPM-HTML>"
855;IfcRelAssignsToProcess;"<EPM-HTML> 

<p>The objectified relationship <i>IfcRelAssignsToProcess</i> handles the assignment of one or many objects to a process or activity. An object can be a product that is the item the process operates on. Processes and activities can operate on things other than products, and can operate in ways other than input and output.</p>

<blockquote><small>EXAMPLE It may be common to define processes
during estimating or scheduling that describe design tasks
(resulting in documents), procurement tasks (resulting in
construction materials), planning tasks (resulting in processes),
etc. Furthermore, the ways in which process can operate on
something might include ""installs"", ""finishes"", ""transports"",
""removes"", etc. The ways are described as operation
types.</small></blockquote>
<p>The inherited attribute <i>RelatedObjects</i> gives the
references to the objects, or object type, which the process
operates on. The <i>RelatingProcess</i> is the process or process
type, that operates on the object. The operation types are
captured in the inherited attribute <i>Name</i>.</p>
<blockquote><small>NOTE The agreement on valid and recognizable
values for the <i>Name</i> attribute is part of view definitions
and implementer agreements.</small></blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5. Has been renamed from IfcRelProcessOperatesOn in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The data type <i>RelatingProcess</i> has been extended to cover also <i>IfcTypeProcess</i>
</blockquote>

</EPM-HTML>"
862;IfcProcess;"<EPM-HTML> 

<p><u>Definition from ISO9000</u>: A process is a set of
activities that are interrelated or that interact with one
another. Processes use resources to transform inputs into
outputs. Processes are interconnected because the output from one
process becomes the input for another process. In effect,
processes are ""glued"" together by means of such input output
relationships.</p>

<p><i>IfcProcess</i> is defined as
one individual activity or event, that is ordered in time, that
has sequence relationships with other processes, which transforms
input in output, and may connect to other other processes through
input output relationships. An <i>IfcProcess</i> can be an
activity (or task), or an event. It takes usually place in
building construction with the intent of designing, costing,
acquiring, constructing, or maintaining products or other and
similar tasks or procedures.</p>
<table summary="""">
<tr valign=""top"">
<td><img src=""figures/IfcProcess_icon_fig.png"" alt=""icon diagram""
border=""0""></td>
</tr>
<tr valign=""top"">
<td>
<p class=""figure"">Figure 2 &mdash; Process relationships and the ICON process diagram.</p>
</td>
</tr>
</table>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0.
</blockquote>

<blockquote class=""change-ifc2x"">
IFC2x PLATFORM CHANGE The attribute <i>Productivity</i> has been removed.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attribute <i>Identification</i> has been promoted from subtypes <i>IfcTask</i> and others.
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Process information relates to other objects by establishing the following relationships:</p>
<ul>
<li><b>Nesting of processes</b> : <i>IfcRelNests</i> - A process can contain sub processes and thereby be nested.</li>
<li><b>Sequencing of processes</b> : <i>IfcRelSequence</i> - Processes can be placed in sequence (including overlapping for parallel tasks), and have predecessors and successors.</li>
<li><b>Assigning process to schedules</b> : <i>IfcRelAssignsToControl</i> - Activities such as tasks, and predominately summary tasks, are assigned to a work schedule.</li>
<li><b>Having a product assigned to the process as input</b> :
<i>IfcRelAssignsToProcess</i> - Products can be assigned as input to a process, such as for construction process planning.</li>
<li><b>Having a product assigned to the process as output</b> :
<i>IfcRelAssignsToProduct</i> - Products can be assigned as output to a process, such as for construction process planning.</li>
<li><b>Having a control assigned to the process as process control</b> : <i>IfcRelAssignsToProcess</i> - Items that act as a
control onto the process can be assigned to a process, such as for cost management (a cost item assigned to a work task).</li>
<li><b>Having a resource assigned to the process as consumed by the process</b> : <i>IfcRelAssignsToProcess</i> - Items that act
as a mechanism to a process, such as labor, material and equipment in cost calculations.</li>
</ul>

</EPM-HTML>"
868;IfcTypeProcess;"<EPM-HTML>

<p><i>IfcTypeProcess</i> defines a
specific (or type) definition of a process or activity without
being assigned to a schedule or a time.˙It is used to define a
process or activity specification, that is, the specific process or
activity information that is common to all occurrences that are
defined for that process or activity type.</p>

<p>An <i>IfcTypeProcess</i> may have a list of property set
attached. Values of these properties are common to all
occurrences of that process or activity type. The type occurrence
relationship is realized using the objectified relationship
<i>IfcRelDefinesByType</i>.</p>

<p>Subtypes of <i>IfcTypeProcess</i> may be exchanged without
being already assigned to subtypes of <i>IfcProcess</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""use-head"">Property set use definition</p>
<p>An <i>IfcTypeProcess</i> may have a list of property sets
attached, accessible by the attribute
<i>SELF\IfcTypeObject.HasPropertySets</i>. Currently there are no
predefined property sets defined as part of the IFC
specification.</p>
<blockquote><small>NOTE: For property sets, a property within an
occurrence property set that is assigned at the process
occurrence, overrides the same property assigned to the process
type.</small></blockquote>

</EPM-HTML>"
873;IfcTypeObject;"<EPM-HTML>

<p>The object type defines the
specific information about a type, being common to all
occurrences of this type. It refers to the specific level of the
well recognized <i>generic - specific - occurrance</i> modeling
paradigm. The <i>IfcTypeObject</i> gets assigned to the
individual object instances (the occurrences) via the
<i>IfcRelDefinesByType</i> relationship.</p>
<blockquote><small>NOTE The terms 'Type' and 'Style' are often
used interchangeably.</small></blockquote>
<p>The object type is represented by a set of property set
definitions. The attached property sets describe the available
alpha-numeric information about the object type. and are used to
define all common properties that apply to all object occurrences
of that type.</p>
<blockquote><small>NOTE If a property having having the same name
is used within the <i>IfcPropertySet</i> assigned to an
<i>IfcTypeObject</i> (and subtypes) and to an occurrence of that
type, then the occurrence property overrides the type property.
See <i>IfcRelDefinesByType</i> for an explanatory
figure.</small></blockquote>
<p>Object types may be exchanged without being already assigned
to objects. An object type may have an indication of the library
(or catalogue) from which its definition originates. This
association is handled by the inherited <i>HasAssociations</i>
relationship pointing to <i>IfcRelAssociatesLibrary</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE The <i>IfcTypeObject</i> is now subtyped from the new supertype <i>IfcObjectDefinition</i>, and the attribute <i>HasPropertySets</i> has been changed from a LIST into a SET.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE (1) The entity <i>IfcTypeObject</i> shall not be instantiated from IFC2x4 onwards. It will be changed into an ABSTRACT supertype in future releases of IFC. (2) The inverse attribute <i>Types</i> has been renamed from <i>ObjectTypeOf</i>.
</blockquote>

</EPM-HTML>"
881;IfcTypeProduct;"<EPM-HTML> 

<p><i>IfcTypeProduct</i> defines a type
definition of a product without being already inserted into a
project structure (without having a placement), and not being
included into the geometric representation context of the
project.˙It is used to define a product specification, that is, the
specific product information that is common to all occurrences
of that product type.</p>

<p>An <i>IfcTypeProduct</i> may have a list of property set
attached and an optional set of product representations. Values
of these properties and the representation maps are common to all
occurrences˙of that product type.˙The type occurrence
relationship is realized using the objectified relationship
<i>IfcRelDefinesByType</i>.</p>

<blockquote><small>NOTE 1˙ The product representations are
defined as representation maps, which gets assigned by a product
instance through the representation item(s) being an
<i>IfcShapeRepresentation</i> and having <i>Items</i> of
type˙<i>IfcMappedItem</i>.</small></blockquote>
<blockquote><small>NOTE 2 ˙The representations at the occurrence
level (represented by subtypes of <i>IfcProduct</i>) can override
the specific representations at the type level, ˙<br></small>
<blockquote>
<ol>
<li><small>for geometric representations: a Cartesian
transformation operator can be applied at the occurrence level,
and˙</small></li>
<li><small>for property sets: A property within an occurrence
property set, assigned at the product occurrence, overrides the
same property assigned to the product type.</small></li>
</ol>
</blockquote>
</blockquote>
<p>An <i>IfcTypeProduct</i> may be exchanged without being
already assigned to subtypes of <i>IfcProduct</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The entity <i>IfcTypeProduct</i> shall not be instantiated from IFC2x4 onwards. It will be changed into an ABSTRACT supertype in future releases of IFC.
</blockquote>

<p class=""use-head"">Geometry use definition</p>
<p>The <i>RepresentationMaps</i> define the type product shape
and multiple geometric representations can be assigned. If a
product occurrence is assigned to the type by using the
<i>IfcRelDefinesByType</i> relationship, then these occurrences
have to reference the representation maps. The reference is
created by one or multiple <i>IfcShapeRepresentation</i>'s having
an <i>IfcMappedItem</i> as <i>Items</i>, that places the
<i>IfcRepresentationMap</i> of the type product into the spatial
contexts, i.e. by using an Cartesian transformation operator to
transform the <i>IfcRepresentationMap</i> into the object
coordinate system of the product occurrence.</p>

<p>Figure 10 illustrates an example of referencing a representation map by
the shape representation of a product occurrence. Here the
Cartesian transformation operator only uses translation, but no
rotation, mirroring, or scaling.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""representation map"">
<tr><td valign=""top""><img src=""figures/IfcTypeProduct_RepresentationMap-1.png"" alt=""representation map"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 10 &mdash; Product type geometry with single placement</p></td></tr>
</table>

<p>Figure 11 illustrates an example of referencing a representation
multiple times map by the shape representation of a product
occurrence. Here the Cartesian transformation operator only uses
translation, but no rotation, mirroring, or scaling. The
different translation values determine the pattern of the
multiple placement.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""representation map"">
<tr><td valign=""top""><img src=""figures/IfcTypeProduct_RepresentationMap-2.png"" alt=""representation map"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 11 &mdash; Product type geometry with multiple placement</td></tr>
</table>

</EPM-HTML>"
886;IfcRelAssignsToProduct;"<EPM-HTML> 
<p>The objectified relationship˙<i>IfcRelAssignsToProduct</i> handles the assignment of objects (subtypes of <i>IfcObject</i>) to a product (subtypes of <i>IfcProduct</i>). The <i>Name</i> attribute should be used to classify the usage of the <i>IfcRelAssignsToProduct</i> objectified relationship. The following <i>Name</i> values are proposed:</p>
<ul>
<li>'Context' : Assignment of a context specific representation, such as of structural members to a different context representation (with potentially different decomposition breakdown) such as of building elements˙for a specific˙context specific representation.˙</li>
<li>'View' : Assignment of a product (via <i>RelatingProduct</i>) that is decomposed according to a discipline view, to another product (via <i>RelatedObjects</i>) that is decomposed according to a different discipline view. An example is the assignment of the architectural slab to a different decomposition of the pre manufactured sections of a slab (under a precast concrete discipline view).</li>
</ul>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2x
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE ˙The reference of a product within a spatial structure is now handled by a new relationship object <i>IfcRelReferencedInSpatialStructure</i>. The <i>IfcRelAssignsToProduct</i> shall not be used to represent this relation from IFC2x3 onwards.
</blockquote>

</EPM-HTML>"
892;IfcTypeResource;"<EPM-HTML>

<p><i>IfcTypeResource</i> defines a specific (or type) definition of a resource.˙It is used to define a resource specification (the specific resource, that is common to all occurrences that are defined for that resource) and could act as a resource template.</p>

<p>An <i>IfcTypeResource</i> may have a list of property sets attached. Values of these properties are common to all occurrences of that resource type. The type occurrence relationship is realized using the objectified relationship <i>IfcRelDefinesByType</i>.</p>

<p>Subtypes of <i>IfcTypeResource</i> may be exchanged without being already assigned to subtypes of <i>IfcResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""use-head"">Property set use definition</p>
<p>An <i>IfcTypeResource</i> may have a list of property sets attached, accessible by the attribute <i>SELF\IfcTypeObject.HasPropertySets</i>. Currently there are no predefined property sets defined as part of the IFC specification.</p>

<blockquote class=""note"">
NOTE: For property sets, a property within an occurrence property set that is assigned at the resource occurrence, overrides the same property assigned to the resource type.
</blockquote>

</EPM-HTML>"
897;IfcRelAssignsToResource;"<EPM-HTML> 

<p>The objectified relationship <i>IfcRelAssignsToResource</i> handles the assignment of objects
(as subtypes of <i>IfcObject</i>), acting as a resource usage or consumption, to a resource (as subtypes of <i>IfcResource</i>).</p>

<blockquote class=""example"">
EXAMPLE The assignment of a resource usage to a construction resource is an application of this generic relationship. It could be an actor, as person or organization assigned to a labor resource, or a raw product assigned to a construction product or material resource).
</blockquote>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
903;IfcResource;"<EPM-HTML> 

<p><i>IfcResource</i> contains the information needed to represent the costs, schedule, and other impacts from the use of a thing in a process. It is not intended to use <i>IfcResource</i> to model the general properties of the things themselves, while an optional linkage from <i>IfcResource</i> to the things to be used can be specified (specifically, the relationship from subtypes of <i>IfcResource</i> to <i>IfcProduct</i> through the <i>IfcRelAssignsToResource</i> relationship). </p> 

<p>There are two basic intended uses of <i>IfcResource</i>. First, if the attributes of the thing are not needed for the purpose of the use of <i>IfcResource</i>, or the types of things are not explicitly modeled in IFC yet, then the linkage between the resource and the thing doesn't have to be instantiated in the system. That is, the attributes of <i>IfcResource</i> (or its subtypes) alone are sufficient to represent the use of the thing as a resource for the purpose of the project. </p> 

<blockquote class=""example""> 
EXAMPLE: construction equipment such as earth-moving vehicles or tools are not currently modeled within the IFC. For the purpose of estimating and scheduling, these can be represented using subtypes of <i>IfcResource</i> alone.
</blockquote> 

<p>Second, if the attributes of the thing are needed for the use of <i>IfcResource</i> objects, and they are modeled explicitly as objects, then the <i>IfcResource</i> instances can be linked to the instances of the type of the things being referenced. Things that might be used as resources and that are already modeled in the IFC include physical products, people and organizations, and materials. The relationship object <i>IfcRelAssignsToResource</i> is provided for this approach.</p> 

<p>The inherited attribute <i>ObjectType</i> is used as a textual code that identifies the resource type. </p> 

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0
</blockquote> 

<blockquote class=""change-ifc2x"">
IFC2x PLATFORM CHANGE: The attributes BaseUnit and ResourceConsumption have been removed from the abstract entity; they are reintroduced at a lower level in the hierarchy.
</blockquote>

</EPM-HTML>"
907;IfcRelDefinesByType;"<EPM-HTML> 
<p>The objectified relationship
<i>IfcRelDefinesByType</i> defines the relationship between an
object type and object occurrences.</p>
<p>The <i>IfcRelDefinesByType</i> is a 1-to-N relationship, as it
allows for the assignment of one type information to a single or
to many objects. Those objects then share the same object type,
and the property sets and properties assigned to the object
type.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attribute <i>RelatedObjects</i> had been demoted from the supertype <i>IfcRelDefines</i> to <i>IfcRelDefinesByType</i>.
</blockquote>

<p class=""use-head"">Relationship use definition</p>

<p>The <i>IfcRelDefinesByType</i> links the object type
definition with the object occurrence. Both may define properties
by assigning an <i>IfcPropertySet</i>, including one or many
subtypes of <i>IfcProperty</i> to either the object type or
object occurrence, as shown in Figure 8.</p>
<p>There are several scenarios to define the same property
set on the object type definition and object occurrence
side:</p>
<ol>
<li>All properties for all object occurrences of a common
object type have the same value - then only the object type
definition has a property set assigned.</li>
<li>All properties for all object occurrences are
different, that is there are no common property values for the
object type definition - then each of the object occurrence has a
property set assigned.</li>
<li>Some properties within the same property set have
common values and are assigned to the object type definition and
some are occurrence specific and assigned (with potentially
different values) to the object occurrences - then:
<ul>
<li>The sum of all properties within a given property set
applicable to an object occurrence is the union of properties
assigned to the object type definition plus the properties
assigned to the object occurrence.</li>
<li>If the object occurrence has a property with the same
<i>IfcProperty.Name</i> in an <i>IfcPropertySet</i>, as the
corresponding object type definition, then the occurrence
property value overrides the type property value.</li>
</ul>
</li>
</ol>

<table border=""0"" cellpadding=""0"" cellspacing=""0"" summary=
""relationship usage"">
<tr><td valign=""top""><img src=""figures/IfcRelDefinesByType_fig-1.png""
alt=""instance diagram"" border=""0""></td></tr>
<td valign=""top""><p class=""figure"">Figure 8 &mdash; Type definition relationships</p></td></tr>
</table>

<p>The following table provides an example of assigning</p>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" summary=
""example for property assignment"">
<tr valign=""top"">
<td><small><b>properties assigned to
<i>IfcWall</i></b></small></td>
<td><small><b>properties assigned to
<i>IfcWallType</i></b></small></td>
<td><small><b>resulting property value for individual
wall</b></small></td>
</tr>
<tr valign=""top"">
<td><small><i>Pset_WallCommon</i></small></td>
<td><small><i>Pset_WallCommon</i></small></td>
<td>˙</td>
</tr>
<tr valign=""top"">
<td><i><small>˙-˙ExtendToStructure</small> = TRUE</i></td>
<td>˙</td>
<td><small>TRUE</small></td>
</tr>
<tr valign=""top"">
<td>˙</td>
<td><small><i>˙-˙ThermalTransmittance</i> = 0.375</small></td>
<td><small>0.375</small></td>
</tr>
<tr valign=""top"">
<td><small><i>˙-˙ExtendToStructure</i> = FALSE</small></td>
<td><small><i>˙-˙ExtendToStructure</i> = TRUE</small></td>
<td><small>FALSE</small></td>
</tr>
</table>
</EPM-HTML>"
910;IfcRelAssignsToControl;"<EPM-HTML> 

<p>The objectified relationship <i>IfcRelAssignsToControl</i> handles the assignment of a control (represented by subtypes of <i>IfcControl</i>) to other objects (represented by subtypes of <i>IfcObject</i>, with the exception of controls).</p>

<blockquote class=""example"">
EXAMPLE˙ The assignment of a performance history (as subtype of <i>IfcControl</i>) for a building service element (as subtype of <i>IfcObject</i>) is an application of this generic relationship.
</blockquote>

<blockquote>
HISTORY˙ New Entity in IFC Release 2.0. Has been renamed from <i>IfcRelControls</i> in IFC Release 2x.
</blockquote>

</EPM-HTML>"
913;IfcControl;"<EPM-HTML> 

<p><i>IfcControl</i> is the abstract generalization of all concepts that control or constrain the utilization of products, processes, or resources in general. It can be seen as a regulation, cost schedule, request or order, or other requirements applied to a product, process or resource whose requirements and provisions must be fulfilled.</p>

<blockquote class=""example"">
EXAMPLE Controls include action requests, cost schedules, project orders, work plans, and work calendars.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Attribute <i>Identification</i> added.
</blockquote> 

<p class=""use-head"">Relationship use definition</p>
<p>Controls have assignments from products, processes, or other objects by using the relationship object <i>IfcRelAssignsToControl</i>.</p>

</EPM-HTML>"
916;IfcRelAssignsToActor;"<EPM-HTML> 
	 
<p>The objectified relationship <i>IfcRelAssignsToActor</i> handles the assignment of objects (subtypes of <i>IfcObject</i>) to an actor (subtypes of <i>IfcActor</i>).</p>

<p>The <i>IfcRelAssignsToActor</i> objectified relationship defines a relationship between an <i>IfcActor</i> and one or many objects. A particular role of the actor played in that relationship can be associated. If specified, it takes priority over the role that may be directly assigned to the person or organization.</p>

<blockquote class=""example"">EXAMPLE: An occupant (as an actor) may rent a flat (as a collection of spaces or a zone). This would be an application of this generic relationship.
</blockquote>

<p>Reference to the objects (or single object) on which the actor acts upon in a certain role (if given) is specified in the inherited <i>RelatedObjects</i> attribute. </p> 

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2.0. Has been renamed from IfcRelActsUpon in IFC Release 2x.
</blockquote>

</EPM-HTML>"
920;IfcActor;"<EPM-HTML> 

<p>The <i>IfcActor</i> defines all actors or human agents involved in a project during its full life cycle. It facilitates the use of person and organization definitions in the resource part of the IFC object model. This includes name, address, telecommunication addresses, and roles.</p>

<blockquote>
HISTORY New Entity in IFC Release 2.0
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Actors are assigned (such as to a process or a resource) by the relationship object that refers to the corresponding object:</p>
<ul>
<li>Process: assigned using <i>IfcRelAssignsToProcess</i></li>
<li>Resource: assigned using <i>IfcRelAssignsToResource</i></li>
</ul>

<p class=""use-head"">Property set use definition</p>
<p>The property sets relating to the <i>IfcActor</i> are defined by <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. They are accessible by the inverse <i>IsDefinedBy</i> relationship. The following property set definitions specific to <i>IfcActor</i> are part of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcKernel/Pset_ActorCommon.xml"" target=""SOURCE"">Pset_ActorCommon</a>: common property set for all actor occurrences</li>
</ul>

</EPM-HTML>"
923;IfcRelAssignsToGroup;"<EPM-HTML> 
<p>The objectified relationship <i>IfcRelAssignsToGroup</i> handles the assignment of object definitions (individual object occurrences as subtypes of <i>IfcObject</i>, and object types as subtypes of <i>IfcTypeObject</i>) to a group (subtypes of <i>IfcGroup</i>).</p>

<p>The relationship handles the assignment of group members to the group object. It allows for grouping arbitrary objects within a group, including other groups. The grouping relationship can be applied in a recursive manner. The resulting group is of type <i>IfcGroup</i>.</p>

<blockquote class=""note"">
NOTE Examples of groups include zones as a grouping of spaces, distribution systems as a grouping of building service components, or structural analysis models as a grouping of structural items.
</blockquote>

<p>The inherited attribute <i>RelatedObjects</i> gives the references to the objects, which are the elements within the group. The <i>RelatingGroup</i> is the group that comprises all elements. The same object or object type can be included in zero, one or many groups. Grouping relationships are not hierarchical.</p>

<p><u>Informal proposition</u>:</p>
<ol>
<li>The group assignment relationship shall be acyclic, that is, a group shall not participate in its own grouping relationship.</li>
</ol>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0. It has been renamed from IfcRelGroups in IFC Release 2x.
</blockquote>

</EPM-HTML>"
927;IfcRelAssignsToGroupByFactor;"<EPM-HTML>

<p>The objectified relationship <i>IfcRelAssignsToGroupByFactor</i> is a specialization of the general grouping mechanism. It allows to add a factor to define the ratio that applies to the assignment of object definitions (individual object occurrences as subtypes of <i>IfcObject</i> and object types as subtypes of <i>IfcTypeObject</i>) to a group (subtypes of <i>IfcGroup</i>).</p>

<p>The ratio can be used to define a percentage assignment.  For example, a <i>Factor</i> of 0.8 would indicate that the object is assigned by 80% to the group, or a <i>Factor</i> of 2.5 would indicate the object is assigned with a weight factor of 2.5 to the group.</p> 

<blockquote class=""note"">
NOTE Examples of factored groups include the assignment of load cases in a load combination in structural analysis, or the assignment of spaces by percentage to different rental zones.
</blockquote>

<p>The same object or object type may be included with the same or different <i>Factor</i> values to many groups. Grouping relationships are not hierarchical.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
929;IfcGroup;"<EPM-HTML> 

<p><i>IfcGroup</i> is an generalization of any arbitrary group. A group is a logical collection of objects. It does not have its own position, nor can it hold its own shape representation. Therefore a group is an aggregation under some non-geometrical / topological grouping aspects.</p>

<blockquote class=""note"">
NOTE Use <i>IfcRelDecomposes</i> together with the appropriate subtypes of <i>IfcProduct</i> to define an aggregation of products that may have its own position and shape representation.
</blockquote>

<blockquote class=""example"">
EXAMPLE An example for a group is a system, since it groups elements under the aspect of their role, regardless of their position in a building.</small></blockquote>

<p>A group can hold any collection of objects (being˙products, processes, controls, resources, actors or other groups). Thus groups can be nested. An object can be part of zero, one, or many groups. Grouping relationships are not required to be hierarchical nor do they imply a dependency.</p>

<blockquote><small>NOTE Use <i>IfcRelDecomposes</i> together with the appropriate subtypes of <i>IfcProduct</i> to define an hierarchical aggregation of products.</small></blockquote>

<p>A group can be exchanged without having already objects within the group collection.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The inverse <i>IsGroupedBy</i> relationship is set to 0..n
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>The group collection is handled by an instance of <i>IfcRelAssignsToGroup</i>, which assigns all group members to the <i>IfcGroup</i>.</p>
<ul>
<li>Objects: included in group using <i>IfcRelAssignsToGroup</i></li>
</ul>
<p>Groups are assigned to other objects (such as a process or a resource) by the relationship object that refers to the corresponding
object:</p>
<ul>
<li>Process: assigned using <i>IfcRelAssignsToProcess</i></li>
<li>Resource: assigned using <i>IfcRelAssignsToResource</i></li>
</ul>
<p>Groups can be subjected to a control. The control information is then assigned:</p>
<ul>
<li>Controls: affecting the group using <i>IfcRelAssignsToControl</i></li>
</ul>

</EPM-HTML>"
940;IfcRelDecomposes;"<EPM-HTML> 

<p>The decomposition relationship,
<i>IfcRelDecomposes</i>, defines the general concept of elements
being composed or decomposed. The decomposition relationship
denotes a whole/part hierarchy with the ability to navigate from
the whole (the composition) to the parts and vice versa.</p>
<p>Decompositions may be constrained by requiring both, the whole
and its parts, to be of the same type - thus establishing a
nesting relationship. Or they may require some form of physical
containment, thus establishing special types of aggregation
relationships.</p>
<blockquote><small>NOTE There are two special names for
decomposition, which are linguistically distinguished, nesting
and aggregation. The subtypes of <i>IfcRelDecomposes</i> will
introduce either the nesting or aggregation convention (see
<i>IfcRelNests</i> and
<i>IfcRelAggregates</i>).</small></blockquote>
<blockquote><small>EXAMPLE A cost element is a nest of other cost
elements. Or a structural frame is an aggregation of beams and
columns. Both are applications of decomposition
relationship.</small></blockquote>
<p>Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts depend
on the existence of the whole. The decomposition relationship can
be applied in a recursive manner, i.e. a decomposed element can
be part in another decomposition. Cyclic references have to be
prevented at application level.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5, it is a generalisation of the IFC2.0 entity <i>IfcRelNests</i>.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The differentiation between the aggregation and nesting is determined to be a non-ordered or an ordered collection of parts. The attributes <i>RelatingObject</i> and <i>RelatedObjects</i> have been demoted to the subtypes.
</blockquote>

</EPM-HTML>"
943;IfcRelAggregates;"<EPM-HTML>

<p>The aggregation relationship
<i>IfcRelAggregates</i> is a special type of the general
composition/decomposition (or whole/part) relationship
<i>IfcRelDecomposes</i>. The aggregation relationship can be
applied to all subtypes of <i>IfcObjectDefinition</i>.</p>
<p>In cases of aggregation of physical elements into a physical
aggregate the shape representation of the whole (within the same
representation identifier) can be taken from the sum of the shape
representations of the parts.</p>
<blockquote><small>EXAMPLE A roof is the aggregation of the roof
elements, such as roof slabs, rafters, purlins, etc. Within the
same representation identifier, e.g. the body geometric
representation, the shape representation of the roof is given by
the shape representation of its parts</small></blockquote>
<p>Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts depend
on the existence of the whole. The behaviour that is implied from
the dependency has to be established inside the applications.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attributes <i>RelatingObject</i> and <i>RelatedObjects</i> are demoted from the supertype <i>IfcRelDecomposes</i>.
</blockquote>

<EPM-HTML>"
947;IfcRelNests;"<EPM-HTML> 

<p>The nesting relationship
<i>IfcRelNests</i> is a special type of the general
composition/decomposition (or whole/part) relationship
<i>IfcRelDecomposes</i>. The nesting relationship can be applied
to all non physical subtypes of object and object types, namely
processes, controls (like cost items), and resources. The nesting
implies an order among the nested parts.</p>
<blockquote><small>EXAMPLE1 A nesting of costs items in a cost
schedule is the composition of complex cost items from other cost
items. The order of the nested cost items underneath the parent
cost item is determined by the order of the list of
<i>RelatedObjects</i>.</small></blockquote>
<blockquote><small>EXAMPLE2 A nesting of work tasks within a work
schedule is the composition of a parent work task from more
specific sub work tasks. The order of the sub tasks underneath
the parent task is determined by the order of the list of
<i>RelatedObjects</i>..</small></blockquote>
<p>Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts depend
on the existence of the whole. The behaviour that is implied from
the dependency has to be established inside the applications.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2.0
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attributes <i>RelatingObject</i> and <i>RelatedObjects</i> are demoted from the supertype <i>IfcRelDecomposes</i>, and <i>RelatedObjects</i> is refined to be a list. The use of <i>IfcRelNests</i> is repurposed to be a nesting of an ordered collections of parts.
</blockquote>

</EPM-HTML>"
951;IfcRelAssociates;"<EPM-HTML>
    <p>
      The association relationship
      <i>IfcRelAssociates</i> refers to external sources of
      information (most notably a classification, library or
      document). There is no dependency implied by the
      association.
    </p>
    <blockquote>
      <small>EXAMPLE Further information may be given
      to the tank equipment (as subtype of <i>IfcProduct</i>) in
      terms of its classification and instruction documents, the
      source of the additional information is held external to
      the IFC project model.</small>
    </blockquote>
    <p>
      Association relationships can be established to objects
      (occurrences as subtypes of <i>IfcObject</i>) or to types 
			(as subtypes of <i>IfcTypeObject</i>).
    </p>
    <blockquote>
      <small>EXAMPLE 1  The classification information
      for the storage tank equipment may be associated to the
      <i>IfcTankType</i> (subtype of <i>IfcTypeObject</i>),
      defining the specific information for all occurencies of
      that tank in the project. Therefore the association of the
      (e.g.) Uniclass notation 'L6814' may be associated by a
      subtype of <i>IfcRelAssociates</i> to the type
      information.</small>
    </blockquote>
    <blockquote>
      <small>EXAMPLE 2  The classification information
      for a particular space within a building may the associated
      to the <i>IfcSpace</i> object (subtype of
      <i>IfcObject</i>), defining a particular occurrence of
      space. Therefore the association of the (e.g.) DIN notation
      'HNF 1.5' may be associated by a subtype of
      <i>IfcRelAssociates</i> to the object.</small>
    </blockquote>
    <p>
      The association relationship establishs a uni-directional
      association. The subtypes of <i>IfcRelAssociates</i>
      establishes the particular semantic meaning of the
      association relationship.
    </p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Entity has been changed into an ABSTRACT supertype
</blockquote>

</EPM-HTML>"
956;IfcRelAssociatesClassification;"<EPM-HTML> 
<p>The objectified relationship
<i>IfcRelAssociatesClassification</i> handles the assignment of a
classification item (items of the select
<i>IfcClassificationSelect</i>) to objects occurrences (subtypes of
<i>IfcObject</i>) or object types (subtypes of
<i>IfcTypeObject</i>).</p>
<p>The relationship is used to assign a classification item, or a
classification system itself to objects. Depending on the type of
the <i>RelatingClassification</i> it is either:</p>
<ul>
<li>a reference to an classification item within an external
classification system, or</li>
<li>a reference to the classification system itself</li>
</ul>
<blockquote>
<p><small>NOTE&nbsp; The reference to a classification item
includes a link to the classification system within which the item
is declared. It assigns the meaning of the classification item to
the object (ocurrence or type). The reference to the classification
system provides the information that the object (occurrence or
type) is governed by the classification system but no assignment of
a particular items has been done yet.</small></p>
</blockquote>
<p>The inherited attribute <i>RelatedObjects</i> define the objects
or object types to which the classification is applied. The
attribute <i>RelatingClassification</i> is the reference to a
classification, applied to the object(s). A single
<i>RelatingClassification</i> can thereby be applied to one or
multiple objects.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
958;IfcRelAssociatesDocument;"<EPM-HTML> 

<p>The objectified relationship (<i>IfcRelAssociatesDocument</i>) handles the assignment of a document information (items of the select <i>IfcDocumentSelect</i>) to objects occurrences (subtypes of <i>IfcObject</i>) or object types (subtypes of <i>IfcTypeObject</i>).</p>

<p>The relationship is used to assign a document reference or a more detailed document information to objects. A single document reference can be applied to multiple objects.</p>

<p>The inherited attribute <i>RelatedObjects</i> define the objects to which the document association is applied. The attribute <i>RelatingDocument</i> is the reference to a document reference, applied to the object(s).</p> 
	 
<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
960;IfcRelAssociatesLibrary;"<EPM-HTML> 

<p>The objectified relationship (<i>IfcRelAssociatesLibrary</i>) handles the assignment of a library item (items of the select <i>IfcLibrarySelect</i>) to subtypes of <i>IfcObjectDefinition</i> or <i>IfcPropertyDefinition</i>.</p> 

<p>The relationship is used to assign a library reference or a more detailed link to a library information to objects, property sets or types. A single library reference can be applied to multiple items.</p> 

<p>The inherited attribute <i>RelatedObjects</i> define the items to which the library association is applied. The attribute <i>RelatingLibrary</i> is the reference to a library reference, applied to the item(s).</p> 

<blockquote class=""history""> 
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
965;IfcRelConnects;"<EPM-HTML> 

<p><i>IfcRelConnects</i> is a connectivity relationship that connects objects under some criteria. As a general connectivity it does not imply constraints, however subtypes of the relationship define the applicable object types for the connectivity relationship and the semantics of the particular connectivity.</p> 

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote> 

</EPM-HTML>"
966;IfcRelDeclares;"<EPM-HTML>

<p>The objectified relationship <i>IfcRelDeclares</i> handles the declaration of objects (subtypes of <i>IfcObject</i>) or properties (subtypes of <i>IfcPropertyDefinition</i>) to a project or project library (represented by <i>IfcProject</i>, or <i>IfcProjectLibrary</i>).</p>

<p>The relationship handles the assignment of other objects, like <i>IfcActor</i>, or <i>IfcTypeObject</i> to the project, or project libary. The attribute <i>RelatedDefinitions</i> provides the references to the first level objects, that are the elements within the context. All other objects that relate to the first level objects are also defined in the context.</p>

<blockquote>
<p><small>NOTE 1&nbsp; Every object (as subtype of <em>IfcObject</em>) has to be declared within the context of a single <em>IfcProject</em>, or of a <em>IfcProjectLibrary</em> assigned to a single <em>IfcProject</em>. This declaration is transitive. For example: the <em>IfcWorkPlan</em> as first level object is declared within the context of <em>IfcProject</em> via <em>IfcRelDeclares</em>, all related <em>IfcWorkSchedule</em>'s are related to the context in a transitive way through <em>IfcWorkPlan</em>.</small></p>

</blockquote>

<blockquote>
<p><small>NOTE 2&nbsp; The assignment excludes subtypes of <em>IfcProduct</em>'s, these are assigned to the <i>IfcProject</i> using the spatial structure approach through <i>IfcSpatialStructureElement</i>(s), where the outer container element such as <em>IfcSite</em> or <em>IfcBuilding</em> has an <i>IfcRelAggregates</i> relationship with the <i>IfcProject</i>.</small></p>
</blockquote>

<p>The <i>RelatingContext</i> is the project, or project library that comprises all elements. The unit assignments and the presentation contexts defined at <em>IfcProject</em> or <em>IfcProjectLibrary</em> apply to all these elements.</p>

<blockquote class=""history"">
HISTORY New entity in Release IFC2x4.
</blockquote>

</EPM-HTML>"
970;IfcContext;"<EPM-HTML>

<p><em>IfcContext</em> is the generalization of a project context in which objects, type objects, property sets, and properties are defined. The <em>IfcProject</em> as subtype of <em>IfcContext</em> provides the context for all information on a construction project, it may include one or several <em>IfcProjectLibrary</em> as subtype of <em>IfcContext</em> to register the included libraries for the project.</p>

<p>Context definitions can be named, using the inherited <em>Name</em> attribute, which should be a user recognizable key or number for the context. The <em>LongName</em> can add a full name. Further explanations to the context can be given using the inherited <em>Description</em> attribute.</p>

<blockquote class=""history"">
HISTORY&nbsp; New abstract entity in IFC2x4.
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Contexts are declared by the relationship object that refers to the corresponding object:</p>
<ul>
<li>Project library to project: <em>IfcProjectLibrary</em> is assigned to <em>IfcProject</em> (both subtypes of using
<em>IfcContext</em>) by using <em>IfcRelDeclares</em></li>
</ul>
<p>More specific relationships are introduced at the level of subtypes.</p>

</EPM-HTML>"
979;IfcProject;"<EPM-HTML> 

<p><i>IfcProject</i> indicates the undertaking of some design, engineering, construction, or
maintenance activities leading towards a product. The project establishes the context for information to be exchanged or shared, and it may represent a construction project but does not have to.  The <em>IfcProject</em>'s main purpose in an exchange structure is to provide the root instance and the context for all other information items included.</p>
<p>The context provided by the <em>IfcProject</em> includes:</p>
<ul>
<li>the default units</li>
<li>the geometric representation context for exchange structures including shape representations
<ul>
<li>the world coordinate system</li>
<li>the coordinate space dimension</li>
<li>the precision used within the geometric representations, and</li>
<li>optionally the indication of the true north relative to the world coordinate system</li>
</ul>
</li>
</ul>

<blockquote class=""history"">HISTORY&nbsp; New Entity in IFC Release 1.0</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The attributes <em>RepresentationContexts</em> and <em>UnitsInContext</em> are made optional and are promoted to supertype <em>IfcContext</em>.
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>The <em>IfcProject</em> is used to reference the root of the spatial structure of a building (that serves as the primary project breakdown and is required to be hierarchical). The spatial structure elements are linked together, and to the <em>IfcProject</em>, by using the objectified relationship <em>IfcRelAggregates</em>. The <em>IfcProject</em> references them by its inverse relationship:</p>
<ul>
<li><em>IfcProject.Decomposes</em> -- it shall be NIL, i.e. the
<em>IfcProject</em> shall not be decomposed into any parts.</li>
<li><em>IfcProject.IsDecomposedBy</em> -- referencing
(<em>IfcSite</em> || <em>IfcBuilding</em>) by
<em>IfcRelAggregates.RelatingObject</em>. The <em>IfcSite</em> or
<em>IfcBuilding</em> referenced shall be the root of the spatial
structure.</li>
</ul>
<p>The <em>IfcProject</em> is also the context for other information about the construction project such as a work plan. Non-product structures are assigned by their first level object to <em>IfcProject</em> using the <em>IfcRelDeclares</em> relationship.</p>

<p>The <em>IfcProject</em> provides the context for spatial elements and the associated products, and for work plans (or other non-product based) descriptions of the construction project. It is handled by two distinct relationship objects as shown in Figure 3.</p>
<blockquote class=""note"">NOTE &nbsp; The spatial structure and the schedule structure can be decomposed. For example the <em>IfcBuilding</em> can be decomposed into <em>IfcBuildingStorey</em>'s, and the <em>IfcWorkPlan</em> can be decomposed into <em>IfcWorkSchedule</em>'s.</blockquote>
<blockquote class=""note"">NOTE &nbsp; The products and tasks can be decomposed further. For example the <em>IfcCurtainWall</em> can be decomposed into <em>IfcMember</em> and <em>IfcPlate</em>, the <em>IfcTask</em> can be decomposed into other <em>IfcTask</em>'s.</blockquote>
<blockquote class=""note"">NOTE &nbsp; The products and tasks can have direct linking relationships. For example the <em>IfcCurtainWall</em> can be assigned to a <em>IfcTask</em> as an input or output for a construction schedule.</blockquote>
<blockquote class=""note"">NOTE &nbsp; The anomaly to use the composition structure through <em>IfcRelAggregates</em> for assigning the uppermost spatial container to <em>IfcProject</em> is due to upward compatibility reasons with earlier releases of this standard.</blockquote>

<table summary=""project relationships"">
<tr valign=""top""><td><img src=""figures/IfcProject_fig-1.png"" alt=""project relationships"" /></td></tr>
<tr valign=""top""><td colspan=""2"">
<p class=""figure"">Figure 3 &mdash; Project spatial and work plan structure</p></td></tr>
</table>

<p>As shown in Figure 4, the <em>IfcProject</em> provides the context for project libraries that in return provide a context to the library items assigned to it. Product types are an example for items that can be included in a project library.</p>

<table summary=""project relationships"">
<tr><td><img src=""figures/IfcProject_fig-2.png"" alt=""project relationships"" /></td></tr>
<tr><td><p class=""figure"">Figure 4 &mdash; Project spatial structure, products and product type library</p></td></tr>
</table>

<p><u>Informal propositions</u>:</p>
<ol>
<li>There shall only be one project within the exchange context. This is enforced by the global rule <em>IfcSingleProjectInstance</em>.</li>
</ol>

</EPM-HTML>"
984;IfcProjectLibrary;"<EPM-HTML>
<p><i>IfcProjectLibrary</i> collects all library elements that are included within a referenced project data set.</p>

<p>Examples for project libraries include:</p>
<ul>
<li>type libraries (also called style or family libraries): a collection of subtypes of <em>IfcTypeObject</em></li>
<li>property definition libraries: a collections of <em>IfcPropertySetTemplate</em> or <em>IfcPropertyTemplates</em></li>
</ul>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""use-head"">Attribute use definition</p>
<dl>
<dt><em>SELF\IfcContext.RepresentationContext</em></dt>
<dd>Context of the representations used within the project library. When the project library includes shape representations for its library type objects, one or several geometric representation contexts need to be included that define the coordinate system, the coordinate space dimensions, and/or the precision factor.<br>
<br></dd>
<dt><em>SELF\IfcContext.UnitsInContext</em></dt>
<dd>Units locally assigned to measure types used within the context of this project library.

<blockquote><small>NOTE&nbsp; It is generally discouraged to use a different length measure and plane angle measure in an included project library compared with the project itself. It may lead to unexpected results for the shape representation of items included in the project library.</small></blockquote>

</dd>
</dl>

<p class=""use-head"">Relationship use definition</p>

<p>Instances of <em>IfcProjectLibrary</em> are assigned to the project context using the <em>IfcRelDeclares</em> relationship and accessible through the inverse attribute <em>HasContext</em>. Individual object types and property (set) templates are assigned to the <em>IfcProjectLibrary</em> using the <em>IfcRelDeclares</em> relationship and are accessible through the inverse attribute <em>Declares</em>.</p>

<p>An <em>IfcProjectLibrary</em> may be decomposed into sub libraries using the relationship <em>IfcRelNests</em>. Sub libraries are accessed by the <em>IfcProjectLibrary</em> through the inverse attribute <em>IsNestedBy</em>.</p>

</EPM-HTML>"
985;IfcRelDefinesByProperties;"<EPM-HTML> 

<p>The objectified relationship
<i>IfcRelDefinesByProperties</i> defines the relationships
between property set definitions and objects. Properties are
aggregated in property sets. Property sets can be either directly
assigned to occurrence objects using this relationship, or
assigned to an object type and assigned via that type to
occurrence objects.</p>
<p>The <i>IfcRelDefinesByProperties</i> is a 1-to-N relationship,
as it allows for the assignment of one property set to a single
or to many objects. Those objects then share the same property
definition.</p>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2.0. Has been renamed from <i>IfcRelAssignsProperties</i> in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attribute <i>RelatedObjects</i> had been demoted from the supertype <i>IfcRelDefines</i> to <i>IfcRelDefinesByProperties</i>.
</blockquote>

</EPM-HTML>"
988;IfcRelDefinesByObject;"<EPM-HTML>

<p>The objectified relationship <i>IfcRelDefinesByObject</i> defines the relationship between an object taking part in an object type decomposition and an object occurrences taking part in an occurrence decomposition of that type.</p>
<p>The <i>IfcRelDefinesByObject</i> is a 1-to-N relationship, as it allows for the assignment of one declaring object information to a single or to many reflected objects. Those objects then share the same object property sets and, for subtypes of <i>IfcProduct</i>, the eventually assigned representation maps.</p>
<p>Only objects that take part in a type decomposition and in an occurrence decomposition of the same type can be connected by the <i>IfcRelDefinesByObject</i> relationship.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""use-head"">Relationship use definition</p>

<p>The <i>IfcRelDefinesByObject</i> links the decomposed object type part, also called the ""declaring part"" with the occurrence of that part inside the occurrence of the decomposed type, also called the ""reflected part"", as shown in Figure 6.</p>

<table border=""0"" cellpadding=""0"" cellspacing=""0"" summary=""relationship usage"">
<tr><td><img src=""figures/IfcRelDefinesByObject_fig-1.png"" alt=""instance diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 6 &mdash; Part definition relationships</p></td></tr>
</table>

<p>The <i>IfcRelDefinesByObject</i> can be used together with the shape representations of the product type as shown in Figure 7. The <i>IfcShapeRepresentation</i> of the ""declaring part"" is referenced by the ""reflected part"". The <i>IfcObjectPlacement</i> of the model occurrence (the whole) determines the position within the project context.</p>

<table border=""0"" cellpadding=""0"" cellspacing=""0"" summary=""relationship usage"">
<tr><td><img src=""figures/IfcRelDefinesByObject_fig-2.png"" alt=""geometry diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 7 &mdash; Part definition relationships with shape representation</td></tr>
</table>

</EPM-HTML>"
991;IfcPropertySetTemplate;"<EPM-HTML>

<p><em>IfcPropertySetTemplate</em> defines the template for all
dynamically extensible property sets represented by
<em>IfcPropertySet</em>. The property set template is a container
of property templates within a property tree. The individual
property templates are interpreted according to their <em>Name</em>
attribute and shall have no values assigned.</p>
<blockquote><span style=""font-size:smaller"">NOTE&nbsp; By
convention an <em>IfcPropertySetTemplate</em> can also be used as a
template for an <em>IfcElementQuantity</em>, being a particular
type of a property set definition.</span></blockquote>
<p>Property set templates can form part of a property library used
and declared within a project. Depending on the
<em>TemplateType</em> the <em>IfcPropertySetTemplate</em> defines a
template for:</p>
<ul>
<li>""Pset_"" - occurrences of <em>IfcPropertySet</em></li>
<li>""QTO_"" - occurrences of <em>IfcElementQuantity</em></li>
</ul>

<blockquote class=""history"">
HISTORY New Entity in IFC2x4.
</blockquote>

<p class=""use-head"">Relationship use definition</p>

<p>The inherited <em>HasContext</em> inverse relation to <em>IfcRelDeclares</em> is used to declare the <em>IfcPropertySetTemplate</em> within a project library. If included in an exchange data set it can then be traversed through the <em>IfcProjectLibrary</em>.</p>

<p>The <em>Defines</em> inverse relation to <em>IfcRelDefinesByTemplate</em> is provided to keep the definition relationship between the <em>IfcPropertySetTemplate</em> and the one to many <em>IfcPropertySet</em>'s, for which it provides the template.</p>

<p>Between <em>IfcProperty</em>'s within the <em>HasProperties</em> set of <em>IfcPropertySet</em> having the same <em>Name</em> attribute value as the <em>IfcPropertyTemplate</em>'s within the <em>HasPropertyTemplates</em> set of <em>IfcPropertySetTemplate</em> an implicit definition relationship is established that assigns the template to the individual properties.</p>

<p>Figure 5 illustrates relationships used for property set templates.</p>

<table summary=""relationships used for property set templates"">
<tr>
<td valign=""top""><img src=
""figures/IfcPropertySetTemplate_fig-1.png"" alt=
""property set template""></td>
</tr>
<tr><td><p class=""figure"">Figure 5 &mdash; Property set template relationships</p></td>
</tr>
</table>
</EPM-HTML>"
998;IfcPropertyTemplateDefinition;"<EPM-HTML>

<p><em>IfcPropertyTemplateDefinition</em> is a generalization of
all property and property set templates. Templates define the
collection, types, names, applicable measure types and units of
individual properties used in a project. The property template
definition can be either:</p>
<blockquote>
<p><strong>Property set template</strong> -
<em>IfcPropertySetTemplate</em>, a collection of property templates
that determine the definition of properties used within a project
context.</p>
<p><strong>Property template</strong> -
<em>IfcPropertyTemplate</em>, a single template that determines the
definition of a particular property used in the same project
context. The template may determine the name, description, data
type, the unit, or a standard expression for each property that is
based on that template.</p>
</blockquote>
<p>The subtypes of <em>IfcPropertyTemplateDefinition</em> are
declared within a project context. The uppermost template
definition (e.g. the <em>IfcPropertySetTemplate</em> including
several <em>IfcPropertyTemplate</em>'s) should be related to the
context, either <em>IfcProject</em>, or <em>IfcProjectLibrary</em>,
using the inherited <em>HasContext</em> inverse attribute.</p>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
1001;IfcPropertyTemplate;"<EPM-HTML>

<p>The <i>IfcPropertyTemplate</i> is an abstract supertype
comprising the templates for all dynamically extensible properties,
either as an <em>IfcComplexPropertyTemplate</em>, or an
<em>IfcSimplePropertyTemplate</em>. These templates determine the
structure of:</p>
<ul>
<li>in case of <em>IfcComplexPropertyTemplate</em>
<ul>
<li>an <em>IfcComplexProperty</em></li>
<li>an <em>IfcPhysicalComplexQuantity</em></li>
</ul>
</li>
<li>in case of <em>IfcSimplePropertyTemplate</em>
<ul>
<li>a subtype of <em>IfcSimpleProperty</em></li>
<li>a subtype of <em>IfcPhysicalSimpleQuantity</em></li>
</ul>
</li>
</ul>
<p>The individual property templates are interpreted according to
their <i>Name</i> attribute and may have a predefined property
type, property unit, and property data type. A template however
shall not have measure values, or quantity values assigned. .</p>

<blockquote class=""note"">
NOTE Property templates can form part of a property library used and attached as part of a project library. In general the <em>IfcPropertySetTemplate</em>, containing the subtypes of <em>IfcPropertyTemplate</em> would be directly linked to the <em>IfcProjectLibrary</em>.
</blockquote>

<blockquote class=""history"">
HISTORY New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
1006;IfcComplexPropertyTemplate;"<EPM-HTML>
<p>The <em>IfcComplexPropertyTemplate</em> defines the template for
all complex properties, either the <em>IfcComplexProperty</em>'s,
or the <em>IfcPhysicalComplexQuantity</em>'s. The individual
complex property templates are interpreted according to their
<em>Name</em> attribute and and optional <em>UsageName</em>
attribute.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
1015;IfcSimplePropertyTemplate;"<EPM-HTML>

<p>The <em>IfcSimplePropertyTemplate</em> defines the template for
all dynamically extensible properties, either the subtypes of
<em>IfcSimpleProperty</em>, or the subtypes of
<em>IfcPhysicalSimpleQuantity</em>. The individual property
templates are interpreted according to their <em>Name</em>
attribute and may have a predefined template type, property units,
and property data types. The correct interpretation of the
attributes:</p>
<ul>
<li><em>PrimaryUnit</em></li>
<li><em>SecondaryUnit</em></li>
<li><em>PrimaryDataType</em></li>
<li><em>SecondaryDataType</em></li>
</ul>
<p>is determined by the <em>TemplateType</em>. The
<em>TemplateType</em> also controls, which subtype of either
<em>IfcSimpleProperty</em> or <em>IfcPhysicalSimpleQuantity</em>
shall be used for property occurrences corresponding to this
template.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>The <em>IfcSimplePropertyTemplate</em> is part of the set of
templates included in the <em>IfcPropertySetTemplate</em>. The
template can be accessed throught the inverse attribute
<em>PartOfPsetTemplate</em> The <em>IfcPropertySetTemplate</em> may
define one or several instances of <em>IfcPropertySet</em> (or
<em>IfcElementQuantity</em>). The definition assignment is
established by the objectified relationship
<em>IfcRelDefinesByTemplate</em>.</p>
<p>There is no direct link between an
<em>IfcSimplePropertyTemplate</em> and a subtype of either
<em>IfcSimpleProperty</em> or <em>IfcPhysicalSimpleQuantity</em>.
The definition relationship between the template and the individual
properties (or quantities) is established by the <em>Name</em>
attributes.</p>
<blockquote>
<p><span style=""font-size:smaller"">Constraints at
<em>IfcPropertySetTemplate</em> and <em>IfcPropertySet</em> (and
<em>IfcElementQuantity</em>) guarantee that the <em>Name</em>
attributes of included property templates and individual properties
are unique.</span></p>
</blockquote>

<table>
<tr><td><img src=""figures/IfcSimplePropertyTemplate_fig-1.png"" alt=
""IfcSimplePropertyTemplate figure 1""></td></tr>
<tr><td><p class=""figure"">Figure 9 &mdash; Property template relationships</p></td></tr>
</table>

</EPM-HTML>"
1045;IfcPreDefinedPropertySet;"<EPM-HTML>

<p><i>IfcPreDefinedPropertySet</i>
is a generalization of all statically defined property sets that
are assigned to an object or type object. The statically or
pre-defined property sets are entities with a fixed list of
attributes having particular defined data types.</p>

<p><i>IfcPreDefinedPropertySet</i>'s can be assigned to objects
and object types but do not have a defining property set
template.</p>

<blockquote class=""history"">
HISTORY New Entity in IFC2x4
</blockquote>

<p class=""use-head"">Relationship use definition</p>
<p>Property sets are related to other objects by using the
relationship object that refers to the corresponding object:</p>
<ul>
<li><b>Occurrence Object</b>: <i>IfcRelDefinesByProperties</i>
using the inverse attribute <i>DefinesOccurrence</i>.</li>
<li><b>Type Object</b>: using a direct link by inverse attribute
<i>DefinesType</i>.</li>
</ul>

</EPM-HTML>"
1046;IfcProxy;"<EPM-HTML> 

<p><i>IfcProxy</i> is intended to be a kind of a container for wrapping objects which are defined by associated properties, which may or may not have a geometric representation and placement in space. A proxy may have a semantic meaning, defined by the <i>Name</i> attribute, and property definitions, attached through the property assignment relationship, which definition may be outside of the definitions given by the current release of IFC.</p>

<p>The <i>ProxyType</i> may give an indication to which high level semantic breakdown of object the semantic definition of the proxy relates to. the <i>Tag</i> attribute may be used to assign a human or system interpretable identifier (such as a serial number or bar code).</p>

<blockquote>
  <p><small>NOTE 1&nbsp; Given that only a
limited number of semantic constructs can be formally defined within
IFC (and it will never be possible to define all), there has to be a
mechanism for capturing those constructs that are not (yet) defined by
IFC. <br>
  <br>
NOTE 2&nbsp; Product proxies are a
mechanism that allows to exchange data that is part of the project but
not necessarily part of the IFC model. Those proxies may have geometric
representations assigned.</small></p>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.
</blockquote>

</EPM-HTML>"
1055;IfcRelFlowControlElements;"<EPM-HTML> 

<p>Objectified relationship between a distribution flow element occurrence instance and one-to-many control element occurrence instances indicating that the control element(s) sense or control some aspect of the flow element. It is applied to <i>IfcDistributionFlowElement</i> and <i>IfcDistributionControlElement</i>.</p>

<p>This relationship may be used to indicate an operation relationship such as an actuator operating a valve, damper, or switch.  It may also be used to indicate a sensing relationship such as a sensor detecting conditions of fluid flow.</p>

<p>This relationship implies a sensing or controlling relationship; if elements are merely connected without any control relationship, then <i>IfcRelConnectsElements</i> should be used.</p>
	<blockquote>
		<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC R2x.<br>
    	</font>
    </blockquote>
</EPM-HTML>
"
1058;IfcDistributionControlElement;"<EPM-HTML> 
<p>The distribution element <i>IfcDistributionControlElement</i> defines occurrence elements of a building automation control system that are used to impart control over elements of a distribution system.</p>

<p>This class defines elements of a building automation control system. These are typically used to control distribution system elements to maintain  variables such as temperature, humidity, pressure, flow, power, or lighting levels, through the modulation, staging or sequencing of mechanical or electrical devices. The three general functional categories of control elements are as follows:</p>

<ul> 
<li>Impart control over flow control elements (<i>IfcFlowController</i>) in a distribution system such as dampers, valves, or relays, typically through the use of actuation (<i>IfcActuator</i>).</li>
<li>Sensing elements (<i>IfcSensor</i>) that measure changes in the controlled variable such as temperature, humidity, pressure, or flow.</li>
<li>Controllers (<i>IfcController</i>) typically classified according to the control action they seek to perform and generally responsible for making decisions about the elements under control.</li>
</ul>
    
<p>Since this class and its subtypes typically relate to many different distribution flow elements (<i>IfcDistributionFlowElement</i>), the objectified relationship <i>IfcRelFlowControlElements</i> has been provided to relate control and flow elements as required.</p>
    
<blockquote>
<font color=""#ff0000"" size=""-1"">IFC2x4 CHANGE: ControlElementId attribute deleted; replaced by classification usage.</font>
<font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC R2.0.<br></font>
</blockquote>
    
<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDistributionControlElement</b> defines the occurrence of any distribution control element; common information about distribution control element types is handled by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a>.  The <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations.  The <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> is attached using the <a href=""../../ifckernel/lexical/ifcreldefinesbytype.htm"">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute.  If the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> has ports or aggregated elements, such objects are reflected at the <b>IfcDistributionControlElement</b> occurrence using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Direct instantiation of <i>IfcDistributionControlElement</i> with <i>IfcObject.ObjectType</i> asserted provides the meaning of a distribution control element proxy.</p>
 
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Property sets may also be specified at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a>, defining the common property data for all occurrences of the same type.  They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDistributionControlElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcDistributionControlElement</b> override the properties defined at <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a>.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcdistributionelement.htm"">IfcDistributionElement</a> and ancestors for inherited property set definitions.</p>

<p><b><u>Classification Use Definition</u></b></p>
<p>In addition to general product and project classification (UniFormat, etc.), classifications may also be applied to indicate a device address or addressing scheme using <a href=""../../ifckernel/lexical/ifcrelassociatesclassification.htm"">IfcRelAssociatesClassification</a> where <i>RelatedObjects</i> contains the  <b>IfcDistributionControlElement</b> and <i>RelatingClassification</i> refers to an <a href=""../../ifcexternalreferenceresource/lexical/ifcclassification.htm"">IfcClassification</a> or <a href=""../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm"">IfcClassificationReference</a>.</p>
<ul>
<li><a href=""../../ifcexternalreferenceresource/lexical/ifcclassification.htm"">IfcClassification</a>: Indicates an addressing scheme managed by the device where <i>ReferenceTokens</i> defines the format of the address to be specified at <i>IfcClassificationReference.ItemReference</i>.  A classification hierarchy may optionally be provided indicating detected or provisioned device addresses.</li>
<li><a href=""../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm"">IfcClassificationReference</a>: Indicates the address of the control element where <i>Identification</i> uniquely identifies the element within the control system as determined by the <i>ClassificationSource</i>.  Several examples are illustrated:
<ul>
<li><b>'BACnet'</b>: BACnetObjectIdentifier in the decimal form '12.15' (Digital Input #15) indicating type ID and instance ID.</li>
<li><b>'IP'</b>: IP Address in the decimal form '192.168.1.2' such as for an IPv4 network.</li>
<li><b>'OPC'</b>: Hierarchical ItemID in the alphanumeric form 'B204.Tank2.Temperature'</li>
<li><b>'X-10'</b>: Alphabetic and numeric code in the form 'B12' (House B, Device 12) indicating House Code and Device Code.</li>
</ul>
</li>
</ul>
<p>Figure 147 illustrates classification usage.</p>
<table>
<tr><td><img alt=""Classification Use Definition"" src=""figures/IfcDistributionControlElement-Classification.png""></td></tr>
<tr><td><p class=""figure"">Figure 147 &mdash; Distribution control classification</p></td></tr>
</table>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElement</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionControlElement</b> and <i>RelatedObjects</i> contains one or more components.  Likewise, a control element may be aggregated within another element.  For example, a thermostat may contain temperature sensors, and a programmable logic controller may contain virtual (software-based) control elements.  Standard types for composition are defined at subtypes.</p>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElement</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href=""../../ifcproductextension/lexical/ifcspatialstructureelement.htm"">IfcSpatialStructureElement</a> (<a href=""../../ifcproductextension/lexical/ifcrelcontainedinspatialstructure.htm"">IfcRelContainedInSpatialStructure</a>) : Indicates the spatial location containing the element.  If an element is aggregated within another element, then only the top-level element participates in this relationship.</li>
<li><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>) : Indicates physical connectivity with another element (but not embedding or flow control), such as a sensor attached to a wall.  <i>IfcRelConnectsElements.RelatingElement</i> refers to the anchored side (for example, wall hosting sensor).</li>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a>) : Indicates ports on the element which may be connected to other elements for control signal transmission or electric power.  Standard port names, types, and directions are defined at subtypes.</li>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm"">IfcDistributionFlowElement</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>) : Indicates a flow element is sensed or controlled by the control element, such as a tank for a level sensor or a valve for an actuator.</li>
</ul>
  
<p><b><u>Assignment Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElement</b> may be assigned to the following entities using relationships as indicated:</p>
<ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm"">IfcDistributionSystem</a> (<a href=""../../ifckernel/lexical/ifcrelassignstogroup.htm"">IfcRelAssignsToGroup</a>): Indicates a system containing interconnected devices, where control elements are typically part of a control system having <i>PredefinedType=CONTROL</i>.</li>
<li><a href=""../../ifccontrolextension/lexical/ifcperformancehistory.htm"">IfcPerformanceHistory</a> (<a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a>): Indicates realtime or historical infomation captured for the device.</li>
</ul>
<p> The <b>IfcDistributionControlElement</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstoproduct.htm"">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionControlElement</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href=""../../ifcprocessextension/lexical/ifctask.htm"">IfcTask</a>: Indicates tasks used to purchase, install, renovate, demolish, operate, or otherwise act upon the element.  If the element has a type, available task types are assigned to the element type.</li>
<li><a href=""../../ifcprocessextension/lexical/ifcprocedure.htm"">IfcProcedure</a>: Indicates procedures used to operate the element.  If the element has a type, available procedure types are assigned to the element type.</li>
<li><a href=""../../ifcprocessextension/lexical/ifcevent.htm"">IfcEvent</a>: Indicates events raised by the element, sequenced by procedures to be followed.  If the element has a type, available event types are assigned to the element type.</li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionControlElement</b> is defined using one of the following entities:</p>
<ul>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>

<li>
<a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>

<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  Material information can also be given at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a>, defining the common attribute data for all occurrences of the same type.  Standard names and material types are defined at subtypes.</p>

<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionControlElement</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>

<ul>
<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>

<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>

<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'.  Such clearance region indicates space that should not intersect with the 'Body' representation of other elements, though may intersect with the 'Clearance' representation of other elements.  The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
</ul>

<p>For all representations, if a <i>IfcDistributionControlElement</i> occurrence is defined by a <i>IfcDistributionControlElementType</i> having a representation of the same identifier, then 'MappedRepresentation' should be used at the occurrence unless overridden.</p>

<p>If materials are defined, geometry of each representation (most typically the 'Body' representation) may be organized into shape aspects where styles may be derived by correlating <i>IfcShapeAspect.Name</i> to a corresponding material (<i>IfcMaterialConstituent.Name</i>).</p>

</EPM-HTML>
"
1060;IfcDistributionPort;"<EPM-HTML>
 
<p>A distribution port is an inlet or outlet of a product through which a particular substance may flow.</p>
 
<p>Distribution ports are used for passage of solid, liquid, or gas substances, as well as electricity for power or communications.  Flow segments (pipes, ducts, cables) may be used to connect ports across products.  Distribution ports are defined by system type and flow direction such that for two ports to be connected, they must share the same system type and have opposite flow directions (one side being a <i>SOURCE</i> and the other being a <i>SINK</i>).  Ports are similar to openings in that they do not have any visible geometry; such geometry is captured at the shape representation of the enclosing element or element type.  Ports may have shape representations that indicate the position, orientation, and cross-section of the connection.</p>
 
<blockquote class=""history"">HISTORY: New entity in IFC2x2</blockquote>
 
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcport.htm"">IfcPort</a> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortCommon.xml"" target=""SOURCE"">Pset_DistributionPortCommon</a></li>
</ul>
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p>
<ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeAirConditioning.xml"" target=""SOURCE"">Pset_DistributionPortTypeAirConditioning</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeAudioVisual.xml"" target=""SOURCE"">Pset_DistributionPortTypeAudioVisual</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeData.xml"" target=""SOURCE"">Pset_DistributionPortTypeData</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeDomesticColdWater.xml"" target=""SOURCE"">Pset_DistributionPortTypeDomesticColdWater</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeDomesticHotWater.xml"" target=""SOURCE"">Pset_DistributionPortTypeDomesticHotWater</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeDrainage.xml"" target=""SOURCE"">Pset_DistributionPortTypeDrainage</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeElectrical.xml"" target=""SOURCE"">Pset_DistributionPortTypeElectrical</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeFireProtection.xml"" target=""SOURCE"">Pset_DistributionPortTypeFireProtection</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">FIREPROTECTION</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeGas.xml"" target=""SOURCE"">Pset_DistributionPortTypeGas</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeHeating.xml"" target=""SOURCE"">Pset_DistributionPortTypeHeating</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeOil.xml"" target=""SOURCE"">Pset_DistributionPortTypeOil</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">OIL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeSewage.xml"" target=""SOURCE"">Pset_DistributionPortTypeSewage</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SEWAGE</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeSignal.xml"" target=""SOURCE"">Pset_DistributionPortTypeSignal</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeTelephone.xml"" target=""SOURCE"">Pset_DistributionPortTypeTelephone</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TELEPHONE</a>)</li>
</ul>
<p>The following property set definitions are applicable to <a href=""../../ifccontrolextension/lexical/ifcperformancehistory.htm"">IfcPerformanceHistory</a>, for which objects are assigned:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryAirConditioning.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryAirConditioning</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryControl.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryControl</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryData.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryData</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryElectrical.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryElectrical</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryGas.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryGas</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryHeating.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryHeating</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryOil.xml"" target=""SOURCE"">Pset_DistributionPortPHistoryOil</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">OIL</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistorySignal.xml"" target=""SOURCE"">Pset_DistributionPortPHistorySignal</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>)</li>
</ul>
 
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionPort</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p>
<ul>
<li><b>'Media'</b>: The solid, liquid, or gas media passing through the port.</li>
</ul>
 
<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionPort</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionPort</b> and <i>RelatedObjects</i> contains one or more components.  Composition use is defined for the following predefined types:
<ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>.  If needed, audio-visual ports may be aggregated into specific streams (channels).<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>.  If needed, control ports may be aggregated into signal lines for indicating pinout specification.<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>.  If needed, data ports may be aggregated into signal lines for indicating pinout specification.<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>.  If needed, electrical ports may be aggregated into modulated signals for data or lighting control.<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTROACCOUSTIC</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTROACCOUSTIC</a>.  If needed, speaker ports may be aggregated into streams (channels) for each speaker.<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TELEPHONE</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TELEPHONE</a>.  If needed, telephone ports may be aggregated for each line.</ul>
 
<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionPort</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href=""../../ifcproductextension/lexical/ifcdistributionelement.htm"">IfcDistributionElement</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a>) : Indicates the host element or element type containing the port.</li>
<li><b>IfcDistributionPort</b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectsports.htm"">IfcRelConnectsPorts</a>) : Indicates a connection to another port having the same type and opposite flow direction.  
For port connections between elements, 
the <i>RelatingPort</i> is set to a port having <i>FlowDirection=SOURCE</i> and 
the <i>RelatedPort</i> is set to a port having <i>FlowDirection=SINK</i>.  
For aggregation scenarios, ports on a device may be mapped to aggregated devices within, 
in which case ports on the outer device indicate a single <i>FlowDirection</i> but have an additional connection internally 
to a port on an aggregated inner device.  
Refer to <a href=""../../ifchvacdomain/lexical/ifcunitaryequipment.htm"">IfcUnitaryEquipment</a> for an example.</li>
</ul>

<p>Figure 149 illustrates distribution port connectivity.</p>

<table>
<tr><td><img alt=""Connection Use Definition"" src=""figures/IfcDistributionPort-Connection.png""></td></tr>
<tr><td><p class=""figure"">Figure 149 &mdash; Distribution port connectivity</p></td></tr>
</table>
 
<p><b><u>Assignment Use Definition</u></b></p>
<p> The <b>IfcDistributionPort</b> may be assigned to the following entities using relationships as indicated:</p>
<ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm"">IfcDistributionSystem</a> (<a href=""../../ifckernel/lexical/ifcrelassignstogroup.htm"">IfcRelAssignsToGroup</a>): Indicates a system containing interconnected devices.</li>
<li><a href=""../../ifccontrolextension/lexical/ifcperformancehistory.htm"">IfcPerformanceHistory</a> (<a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a>): Indicates realtime or historical infomation captured for the device.</li>
</ul>
<p> The <b>IfcDistributionPort</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstoproduct.htm"">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionPort</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm"">IfcDistributionSystem</a>: Indicates a system that is hosted by the port, as the origination.
</li>
</ul>
 
<p><b><u>Representation Use Definition</u></b></p>
<p>The representation of <b>IfcDistributionPort</b> is given by <a href=""../../ifcrepresentationresource/lexical/ifcproductdefinitionshape.htm"">IfcProductDefinitionShape</a>, allowing multiple shape and topology representations.  Included are:</p>
<ul>
<li><a href=""../../ifcrepresentationresource/lexical/ifcshaperepresentation.htm"">IfcShapeRepresentation</a>: The optional shape representation describes the connection volume and supports indication of the port position and orientation.  The position is typically the midpoint of the physical connection, and the orientation points in the flow direction normal to the physical connection. Upon connecting elements through ports with rigid connections, each object is aligned such that the effective <i>Location</i>, <i>Axis</i>, and <i>RefDirection</i> of each port is aligned to be equal.
<ul>
<li><b>'Body'</b>: The shape of the port.</li>
</ul>
</li>
</ul>
 
</EPM-HTML>"
1106;IfcDistributionControlElementType;"<EPM-HTML>
<p>The element type <i>IfcDistributionControlElementType</i> defines a list of commonly shared property set definitions of an element and an optional set of product representations.  It is used to define an element specification (the specific product information that is common to all occurrences of that product type).</p> 
	 
<p>Distribution control element types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p> 
	
<p>The occurrences of the <i>IfcDistributionControlElementType</i> are represented by instances of <i>IfcDistributionControlElement</i> or its subtypes.</p> 
    
<blockquote>
<font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC Release 2x2.<br></font>
</blockquote>


<p><b><u>Declaration Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be declared within a project or project library using <i>IfcRelDeclares</i> where <i>RelatingContext</i> refers to the project or library and <i>RelatedDefinitions</i> includes the element type.  Inclusion within <i>IfcProject</i> indicates the type is editable within the direct project and may be available to other referencing projects that may incorporate the type.  Inclusion within <i>IfcProjectLibrary</i> indicates the type is incorporated from a referenced project.  Default units and coordinate systems (used for representations, materials, and property sets) are indicated by the declaring project or library.</p>

<p><b><u>Classification Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be classified using <i>IfcRelAssociatesClassification</i> where <i>RelatingClassification</i> refers to an <i>IfcClassificationReference</i> indicating a classification notation. Classifications may refer to industry standards such as MasterFormat, OmniFormat, or UniFormat.  Classifications may also refer to organization-specific, project-specific, or system-specific designations.  Classification reference identification schemes are described by <i>IfcClassification.ReferenceTokens</i>.</p>

<p><b><u>Document Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be documented using <i>IfcRelAssociatesDocument</i> where <i>RelatingDocument</i> refers to an <i>IfcDocumentReference</i> indicating content within a document, or <i>IfcDocumentInformation</i> indicating an entire document. Document information may refer to arbitrary attachments such as text or multimedia, while document references may refer to items within particular formats (such as XML element IDs) where there is need to synchronize document information with model information.  Document reference identification schemes depend on the particular document format.</p>

<p><b><u>Library Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be published to a model server using <i>IfcRelAssociatesLibrary</i> where <i>RelatingLibrary</i> refers to an <i>IfcLibraryReference</i> indicating the unique identification within the published project.  If the published project is IFC format, then <i>IfcLibraryReference.Identification</i> shall match <i>IfcRoot.GlobalID</i> of the published (master) project, using the same encoding as described for <i>IfcGloballyUniqueId</i>.  Multiple library references may be provided to indicate alternate names and descriptions for particular languages.  If the element type is declared within <i>IfcProject</i>, then <i>IfcLibraryInformation.Location</i> and <i>IfcLibraryInformation.Version</i> indicate the URL and version as last published.  If the element type is declared within <i>IfcProjectLibrary</i>, then the library information indicates the location and version of the definition as last retrieved.</p>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionFlowElementType</b> and <i>RelatedObjects</i> contains one or more components.  For example, a thermostat type may be decomposed into temperature sensors.  Standard types for composition are defined at occurrences for subtypes.</p>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a>) : Indicates port definitions on the element to be instantiated at occurrences.  Standard port names, types, and directions are defined at occurrences for subtypes.</li>
</ul>
  
<p><b><u>Assignment Use Definition</u></b></p>
<p> The <b>IfcDistributionControlElementType</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstoproduct.htm"">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionControlElementType</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href=""../../ifcprocessextension/lexical/ifctasktype.htm"">IfcTaskType</a>: Indicates task types available to purchase, install, renovate, demolish, operate, or otherwise act upon occurrences of the element type.  Such task types may be instantiated as task occurrences assigned to occurrences of the element type.  Prices (such as for purchasing or shipping) may be established by resource types assigned to task types.</li>
<li><a href=""../../ifcprocessextension/lexical/ifcproceduretype.htm"">IfcProcedureType</a>: Indicates procedure types available to operate occurrences of the element type.  Such procedure types may be instantiated as procedure occurrences assigned to occurrences of the element type.</li>
<li><a href=""../../ifcprocessextension/lexical/ifceventtype.htm"">IfcEventType</a>: Indicates event types available to be raised by occurrences of the element, sequenced by procedures to be followed.  Such event types may be instantiated as event occurrences assigned to occurrences of the element type.</li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionControlElementType</b> is defined using one of the following entities:</p>
<ul>
<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>
<li>
<a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.</p>

<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionControlElementType</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>
<ul>

<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>

<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>

<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'.  Such clearance region indicates space that should not intersect with the 'Body' representation between element occurrences, though may intersect with the 'Clearance' representation of other element occurrences.  The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
</ul>

<blockquote>
<font size=""-1"">
NOTE: The product representations are defined as representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which get assigned by an element occurrence instance through the <i>IfcShapeRepresentation.Item[1]</i> being an <i>IfcMappedItem</i>.
</font>
</blockquote>



</EPM-HTML>"
1107;IfcDistributionFlowElementType;"<EPM-HTML>
<p>The element type <i>IfcDistributionFlowElementType</i> defines a list of commonly shared property set definitions of an element and an optional set of product representations.  It is used to define an element specification (the specific product information that is common to all occurrences of that product type).</p> 
	     
<p>Distribution flow element types (orthe instantiable subtypes) may be exchanged without being already assigned to occurrences.</p> 
	
<p>The occurrences of the <i>IfcDistributionFlowElementType</i> are represented	by instances of <i>IfcDistributionFlowElement</i> or its subtypes.</p> 
    
<blockquote class=""history"">HISTORY: New entity in IFC Release 2x2.</blockquote>

<p><b><u>Declaration Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be declared within a project or project library using <i>IfcRelDeclares</i> where <i>RelatingContext</i> refers to the project or library and <i>RelatedDefinitions</i> includes the element type.  Inclusion within <i>IfcProject</i> indicates the type is editable within the direct project and may be available to other referencing projects that may incorporate the type.  Inclusion within <i>IfcProjectLibrary</i> indicates the type is incorporated from a referenced project.  Default units and coordinate systems (used for representations, materials, and property sets) are indicated by the declaring project or library.</p>

<p><b><u>Classification Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be classified using <i>IfcRelAssociatesClassification</i> where <i>RelatingClassification</i> refers to an <i>IfcClassificationReference</i> indicating a classification notation. Classifications may refer to industry standards such as MasterFormat, OmniFormat, or UniFormat.  Classifications may also refer to organization-specific, project-specific, or system-specific designations.  Classification reference identification schemes are described by <i>IfcClassification.ReferenceTokens</i>.</p>

<p><b><u>Document Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be documented using <i>IfcRelAssociatesDocument</i> where <i>RelatingDocument</i> refers to an <i>IfcDocumentReference</i> indicating content within a document, or <i>IfcDocumentInformation</i> indicating an entire document. Document information may refer to arbitrary attachments such as text or multimedia, while document references may refer to items within particular formats (such as XML element IDs) where there is need to synchronize document information with model information.  Document reference identification schemes depend on the particular document format.</p>

<p><b><u>Library Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be published to a model server using <i>IfcRelAssociatesLibrary</i> where <i>RelatingLibrary</i> refers to an <i>IfcLibraryReference</i> indicating the unique identification within the published project.  If the published project is IFC format, then <i>IfcLibraryReference.Identification</i> shall match <i>IfcRoot.GlobalID</i> of the published (master) project, using the same encoding as described for <i>IfcGloballyUniqueId</i>.  Multiple library references may be provided to indicate alternate names and descriptions for particular languages.  If the element type is declared within <i>IfcProject</i>, then <i>IfcLibraryInformation.Location</i> and <i>IfcLibraryInformation.Version</i> indicate the URL and version as last published.  If the element type is declared within <i>IfcProjectLibrary</i>, then the library information indicates the location and version of the definition as last retrieved.</p>

<p>Figure 148 illustrates a project containing a light fixture in a building, where the definition of the light fixture is obtained from an external project.</p>

<table>
<tr><td><img alt=""Library Use Definition"" src=""figures/IfcDistributionFlowElement-Library.png""></td></tr>
<tr><td><p class=""figure"">Figure 148 &mdash; Distribution flow element library</p></td></tr>
</table>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionFlowElementType</b> and <i>RelatedObjects</i> contains one or more components.  For example, a cable type may be decomposed into wires.  Standard types for composition are defined at occurrences for subtypes.</p>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a>) : Indicates port definitions on the element to be instantiated at occurrences.  Standard port names, types, and directions are defined at occurrences for subtypes.</li>
</ul>
  
<p><b><u>Assignment Use Definition</u></b></p>
<p> The <b>IfcDistributionFlowElementType</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstoproduct.htm"">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionFlowElementType</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href=""../../ifcprocessextension/lexical/ifctasktype.htm"">IfcTaskType</a>: Indicates task types available to purchase, install, renovate, demolish, operate, or otherwise act upon occurrences of the element type.  Such task types may be instantiated as task occurrences assigned to occurrences of the element type.  Prices (such as for purchasing or shipping) may be established by resource types assigned to task types.</li>
<li><a href=""../../ifcprocessextension/lexical/ifcproceduretype.htm"">IfcProcedureType</a>: Indicates procedure types available to operate occurrences of the element type.  Such procedure types may be instantiated as procedure occurrences assigned to occurrences of the element type.</li>
<li><a href=""../../ifcprocessextension/lexical/ifceventtype.htm"">IfcEventType</a>: Indicates event types available to be raised by occurrences of the element, sequenced by procedures to be followed.  Such event types may be instantiated as event occurrences assigned to occurrences of the element type.</li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionFlowElementType</b> is defined using one of the following entities:</p>
<ul>
<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a>: For elements having a constant cross-section, this defines the material profile which may be used to generate the 'Body' representation at occurrences (for parametric definitions not having representation), or for analysis purposes.</li>
<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>
<li>
<a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.</p>


<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionFlowElementType</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>

<ul>

<li><b>'Axis'</b>: Represents the 3D flow path of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'Curve3D' and containing a single <i>IfcBoundedCurve</i> subtype such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, or <i>IfcCompositeCurve</i>.  For elements containing directional ports (<i>IfcDistributionPort</i> with <i>FlowDirection</i> of <i>SOURCE</i> or <i>SINK</i>), the direction of the curve indicates direction of flow where a <i>SINK</i> port is positioned at the start of the curve and a <i>SOURCE</i> port is positioned at the end of the curve.  This representation is most applicable to flow segment types (pipes, ducts, cables), however may be used at other elements to define a primary flow path if applicable.</li> 

<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>

<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>

<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'.  Such clearance region indicates space that should not intersect with the 'Body' representation between element occurrences, though may intersect with the 'Clearance' representation of other element occurrences.  The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
</ul>

<li><b>'Lighting'</b>: Represents the light emission of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'LightSource' and containing one or more <i>IfcLightSource</i> subtypes.  This representation is most applicable to lamps and light fixtures, however may be used at other elements that emit light.
</ul>

<p>If an element type is defined parametrically (such as a flow segment type defining common material profile but no particular length or path), then no representations shall be asserted at the type.</p>

<blockquote>
<font size=""-1"">
NOTE: The product representations are defined as representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which get assigned by an element occurrence instance through the <i>IfcShapeRepresentation.Item[1]</i> being an <i>IfcMappedItem</i>.
</font>
</blockquote>


</EPM-HTML>"
1117;IfcEnergyConversionDeviceType;"<EPM-HTML>
<p>The element type <i>IfcEnergyConversionType</i> defines a list of commonly shared property
	set definitions of an energy conversion device and an optional set of product representations.
	It is used to define an energy conversion device specification (i.e. the specific product
	information, that is common to all occurrences of that product type).</p> 
	 
	<blockquote>
		<font size=""-1"">
		NOTE: The product representations are defined as
		representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
		get assigned by an element occurrence instance through the
		<i>IfcShapeRepresentation.Item[1]</i> being an
		<i>IfcMappedItem</i>.
    	</font>
    </blockquote>
    
    <p>A energy conversion type is used to define the common properties of a
	energy conversion device that may be applied to many occurrences of that type. 
An energy conversion device is a building systems device that converts energy from one form into another such 
as a boiler (i.e., combusting gas to heat water), chiller (i.e., using a refrigeration cycle to cool a 
liquid), or a cooling coil (i.e., using the phase-change characteristics of a refrigerant to cool air).
	Energy conversion types (or the instantiable subtypes) may be exchanged 
    without being already assigned to occurrences.</p> 
	
    <p>The occurrences of the <i>IfcEnergyConversionType</i> are represented
	by instances of <i>IfcEnergyConversionDevice</i>.</p> 
    
	<blockquote>
		<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC Release 2x2.<br>
    	</font>
    </blockquote>

</EPM-HTML>"
1118;IfcFlowMovingDeviceType;"<EPM-HTML>
	<p>The element type <i>IfcFlowMovingDeviceType</i> defines a list of commonly shared property
	set definitions of a flow moving device and an optional set of product representations.
	It is used to define a flow moving device specification (i.e. the specific product
	information, that is common to all occurrences of that product type).</p> 
	 
	<blockquote>
		<font size=""-1"">
		NOTE: The product representations are defined as
		representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
		get assigned by an element occurrence instance through the
		<i>IfcShapeRepresentation.Item[1]</i> being an
		<i>IfcMappedItem</i>.
    	</font>
    </blockquote>
    
    <p>A flow moving type is used to define the common properties of a
	flow moving device that may be applied to many occurrences of that type.
A flow moving device is a device that is used to produce a pressure differential in a distribution system, 
such as a pump, fan, compressor, etc. 
	Flow moving types (or the instantiable subtypes) may be exchanged 
    without being already assigned to occurrences.</p> 
	
    <p>The occurrences of the <i>IfcFlowMovingDeviceType</i> are represented
	by instances of <i>IfcFlowMovingDevice</i>.</p> 
    
	<blockquote>
		<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC Release 2x2.<br>
    	</font>
    </blockquote>

</EPM-HTML>"
1119;IfcFlowControllerType;"<EPM-HTML>
<p>The element type <i>IfcFlowControllerType</i> defines a list of commonly shared property
	set definitions of a flow controller and an optional set of product representations.
	It is used to define a flow controller specification (i.e. the specific product
	information, that is common to all occurrences of that product type).</p> 
	 
	<blockquote>
		<font size=""-1"">
		NOTE: The product representations are defined as
		representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
		get assigned by an element occurrence instance through the
		<i>IfcShapeRepresentation.Item[1]</i> being an
		<i>IfcMappedItem</i>.
    	</font>
    </blockquote>
    
    <p>A flow controller type is used to define the common properties of a
	flow controller that may be applied to many occurrences of that type.
A flow controller is a device that regulates flow within a distribution system, such as a valve in a piping 
system, modulating damper in an air distribution system, or electrical switch in an electrical distribution 
system. Flow controller types (or the instantiable subtypes) may be exchanged 
    without being already assigned to occurrences.</p> 
	
    <p>The occurrences of the <i>IfcFlowControllerType</i> are represented
	by instances of <i>IfcFlowController</i> or its subtypes.</p> 
    
	<blockquote>
		<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC Release 2x2.<br>
    	</font>
    </blockquote>

</EPM-HTML>"
1120;IfcFlowSegmentType;"<EPM-HTML>
	<p>The element type <i>IfcFlowSegmentType</i> defines a list of commonly shared property
	set definitions of a flow segment and an optional set of product representations.
	It is used to define a flow segment specification (i.e. the specific product
	information, that is common to all occurrences of that product type).</p> 
	 
    <blockquote>
		<font size=""-1"">
		NOTE: The product representations are defined as
		representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
		get assigned by an element occurrence instance through the
		<i>IfcShapeRepresentation.Item[1]</i> being an
		<i>IfcMappedItem</i>.
    	</font>
    </blockquote>
    
    <p>A flow segment type is used to define the common properties of a
	flow segment that may be applied to many occurrences of that type.
A flow segment is a section of a distribution system, such as a duct, pipe, conduit, etc. that typically has 
only two ports. 
	Flow segment types (or the instantiable subtypes) may be exchanged 
    without being already assigned to occurrences.</p> 
	
    <p>The occurrences of the <i>IfcFlowSegmentType</i> are represented
	by instances of <i>IfcFlowSegment</i> or its subtypes.</p> 
    
	<blockquote>
		<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC Release 2x2.<br>
    	</font>
    </blockquote>


<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionFlowSegmentType</b> is defined using one of the following entities:</p>
<ul>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> : This defines the material cross section which may be used to generate the 'Body' representation at occurrences (for parametric definitions not having representation), or for analysis purposes.</li>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> : For elements containing multiple materials where profiles are not applicable, this indicates materials at named aspects.</i>
</li>

<li>
<a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a> : For elements comprised of a single material where profiles are not applicable, this indicates the material.</li>
</ul>


</EPM-HTML>
"
1121;IfcFlowFittingType;"<EPM-HTML>
	<p>The element type <i>IfcFlowFittingType</i> defines a list of commonly shared property
	set definitions of a flow fitting and an optional set of product representations.
	It is used to define a flow fitting specification (i.e. the specific product
	information, that is common to all occurrences of that product type).</p> 
	 
	<blockquote>
		<font size=""-1"">
		NOTE: The product representations are defined as
		representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
		get assigned by an element occurrence instance through the
		<i>IfcShapeRepresentation.Item[1]</i> being an
		<i>IfcMappedItem</i>.
    	</font>
    </blockquote>
    
    <p>A flow fitting type is used to define the common properties of a
	flow fitting that may be applied to many occurrences of that type.
A flow fitting is a device that is used to interconnect flow segments or other fittings within a distribution 
system, such as a tee in a ducted system that branches flow into two directions, a junction box in an 
electrical distribution system, etc. 
	Flow fitting types (or the instantiable subtypes) may be exchanged 
    without being already assigned to occurrences.</p> 
	
    <p>The occurrences of the <i>IfcFlowFittingType</i> are represented
	by instances of <i>IfcFlowFitting</i> or its subtypes.</p> 
    
	<blockquote>
		<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC Release 2x2.<br>
    	</font>
    </blockquote>

</EPM-HTML>"
1122;IfcFlowStorageDeviceType;"<EPM-HTML>
<p>The element type <i>IfcFlowStorageDeviceType</i> defines a list of commonly shared property set definitions of a flow storage device and an optional set of product representations.  It is used to define a flow storage device specification (the specific product information that is common to all occurrences of that product type).</p> 
	     
<p>A flow storage device is a device used for the temporary storage of a fluid (such as a tank) or the voltage potential induced by the induced electron flow (such as a battery). Flow storage types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p> 
	
<p>The occurrences of the <i>IfcFlowStorageDeviceType</i> are represented by instances of <i>IfcFlowStorageDevice</i> or its subtypes.</p> 
    
<blockquote>
<font color=""#0000ff"" size=""-1"">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>

</EPM-HTML>"
1123;IfcFlowTreatmentDeviceType;"<EPM-HTML>
<p>The element type <i>IfcFlowTreatmentDeviceType</i> defines a list of commonly shared property set definitions of a flow treatment device and an optional set of product representations. It is used to define a flow treatment device specification (the specific product information that is common to all occurrences of that product type).</p> 
	     
<p>A flow treatment device is a device used to change the physical properties of the medium, such as an air, oil 
or water filter (used to remove particulates from the fluid), or a duct silencer (used to attenuate noise).  Flow treatment types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p> 
	
<p>The occurrences of the <i>IfcFlowTreatmentDeviceType</i> are represented by instances of <i>IfcFlowTreatmentDevice</i> or its subtypes.</p> 
    
<blockquote>
<font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC Release 2x2.<br></font>
</blockquote>

</EPM-HTML>"
1124;IfcFlowTerminalType;"<EPM-HTML>
<p>The element type <i>IfcFlowTerminalType</i> defines a list of commonly shared property set definitions of a flow terminal and an optional set of product representations.  It is used to define a flow terminal specification (the specific product information that is common to all occurrences of that product type).</p> 
	     
<p>A flow terminal type is used to define the common properties of a flow terminal that may be applied to many occurrences of that type.  A flow terminal acts as a terminus or beginning element in a distribution system such as a ceiling register in a ducted air distribution system, a sink in a waste-water system, or a light fixture in an electrical lighting system. Flow terminal types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p> 
	
<p>The occurrences of the <i>IfcFlowTerminalType</i> are represented by instances of <i>IfcFlowTerminal</i> or its subtypes.</p> 
    
<blockquote>
<font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC Release 2x2.<br></font>
</blockquote>

</EPM-HTML>"
1125;IfcDistributionChamberElementType;"<EPM-HTML>
 
<p>The distribution flow element type <b>IfcDistributionChamberElementType</b> defines commonly shared information for occurrences of distribution chamber elements.  The set of shared information may include:</p>
<ul>
<li>common properties with shared property sets</li>
<li>common materials</li>
<li>common ports</li>
<li>common composition of elements</li>
<li>common assignment of process types</li>
<li>common representations of shape and style</li>
</ul>
<p>It is used to define a distribution chamber element specification (i.e. the specific product information, that is common to all occurrences of that product type).  Distribution Chamber Element types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcDistributionChamberElementType</b> are represented by instances of <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelement.htm"">IfcDistributionChamberElement</a>.</p>
</p>
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote>
 
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementCommon.xml"" target=""SOURCE"">Pset_DistributionChamberElementCommon</a></li>
</ul>
The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p>
<ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeFormedDuct.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeFormedDuct</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">FORMEDDUCT</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionChamber.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeInspectionChamber</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">INSPECTIONCHAMBER</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionPit.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeInspectionPit</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">INSPECTIONPIT</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeManhole.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeManhole</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">MANHOLE</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeMeterChamber.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeMeterChamber</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">METERCHAMBER</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeSump.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeSump</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">SUMP</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeTrench.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeTrench</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">TRENCH</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeValveChamber.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeValveChamber</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">VALVECHAMBER</a>)</li>
</ul>
 
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionChamberElementType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p>
<ul>
<li><b>'Base'</b>: The material from which the base of the duct is constructed.</li>
<li><b>'Cover'</b>: The material from which the access cover to the chamber is constructed.</li>
<li><b>'Fill'</b>: The material that is used to fill the duct (where used).</li>
<li><b>'Wall'</b>: The material from which the wall of the duct is constructed.</li>
</ul> 
 
</EPM-HTML>

"
1139;IfcDistributionSystem;"<EPM-HTML>
<p>A distribution system is a network designed to receive, store, maintain, distribute, or control the flow of a distribution media. A common example is a heating hot water system that consists of a pump, a tank, and an interconnected piping system for distributing hot water to terminals.</p>

<blockquote class=""history"">HISTORY New entity in IFC 2x4.</blockquote>

<p>The group <i>IfcDistributionSystem</i>
defines the occurrence of a specialized system for use within the context of building services.</p>

<blockquote>
    <font size=""-1"">
NOTE: For electrical power systems, <i>IfcElectricalCircuit</i> has been used for low-voltage (12-1000 V) power systems and has been deprecated in IFC2x4; <i>IfcDistributionSystem</i> with PredefinedType 'ELECTRICAL' should now be used instead.
    </font>
</blockquote>

<p>Important functionalities for the description of a distribution system are derived from existing IFC entities:</p>

<ul><li>From <i>IfcSystem</i> it inherits the ability to couple the distribution system via <i>IfcRelServicesBuildings</i> to one or more <i>IfcSpatialElement</i> subtypes as necessary.</li></ul>

<ul><li>From <i>IfcGroup</i> it inherits the inverse attribute <i>IsGroupedBy</i>, pointing to the relationship class <i>IfcRelAssignsToGroup</i>. This allows to group distribution elements (instances of <i>IfcDistributionElement</i> subtypes), and in special cases ports directly (instances of <i>IfcDistributionPort</i>).</li></ul>

<ul><li>From <i>IfcObject</i> it inherits the inverse attribute <i>IsDecomposedBy</i> pointing to the relationship class <i>IfcRelAggregates</i>. It provides the hierarchy between the separate (partial) distribution systems.  For example, an electrical main circuit may be aggregated into branch circuits.</li></ul>


<p><b><u>Property Set Use Definition</u></b>:</p>

<p>The property sets relating to this entity are defined by the <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. It is accessible by the inverse <i>IsDefinedBy</i> relationship.  The following property set definitions specific to this entity are part of this IFC release:
</p> 
<ul> 
 <li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionSystemCommon.xml""
     target=SOURCE>Pset_DistributionSystemCommon</a>: common property set for distribution system occurrences
 </li>
 <li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionSystemTypeElectrical.xml""
     target=SOURCE>Pset_DistributionSystemTypeElectrical</a>: property set for electrical systems
 </li>
 <li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionSystemTypeVentilation.xml""
     target=SOURCE>Pset_DistributionSystemTypeVentilation</a>: property set for ventilation systems
 </li>
</ul> 


<p><b><u>Assignment Use Definition</u></b>:</p>

<p>For the most common case of an <i>IfcDistributionElement</i> subtype containing ports of a particular <i>PredefinedType</i> that all belong to the same distribution system, the <i>IfcDistributionElement</i> is assigned to the <i>IfcDistributionSystem</i> via the <i>IfcRelAssignsToGroup</i> relationship, where <i>IfcDistributionPort</i>'s are implied as part of the corresponding system based on their <i>PredefinedType</i>.  An <i>IfcDistributionElement</i> may belong to multiple systems, however only one <i>IfcDistributionSystem</i> of a particular <i>PredefinedType</i>.</p>

<p>For rare cases where an <i>IfcDistributionElement</i> subtype contains ports of the same <i>PredefinedType</i> yet different ports belong to different systems, alternatively each <i>IfcDistributionPort</i> may be directly assigned to a single <i>IfcDistributionSystem</i> via the <i>IfcRelAssignsToGroup</i> relationship, where the <i>PredefinedType</i> must match.  Such assignment indicates that the <i>IfcDistributionSystem</i> assigned from the <i>IfcDistributionPort</i> overrides any such system of the same <i>PredefinedType</i> assigned from the containing <i>IfcDistributionElement</i>, if any.</p>

<p>Additionally, an <i>IfcDistributionSystem</i> may in turn be assigned to an <i>IfcDistributionPort</i> indicating the host or origination of the system using <i>IfcRelAssignsToProduct</i>.</p>

<blockquote>
    <font size=""-1"">
EXAMPLE: A gas-powered hot water heater may have three ports: GAS, DOMESTICCOLDWATER, and DOMESTICHOTWATER.  The heater is a member of two systems (GAS and DOMESTICCOLDWATER), and hosts one system (DOMESTICHOTWATER) at the corresponding port.
    </font>
</blockquote>

<p>Figure 150 illustrates a distribution system for an electrical circuit.</p>

<table>
<tr><td><img alt=""Instance diagram for electrical circuit"" src=""figures/IfcDistributionSystem-01.png"" ></td></tr>
<tr><td><p class=""figure"">Figure 150 &mdash; Distribution system assignment</p></td></tr>
</table>

</p>

</EPM-HTML>
"
1142;IfcDistributionFlowElement;"<EPM-HTML> 
<p>The distribution element <i>IfcDistributionFlowElement</i> defines occurrence elements of a distribution system that facilitate the distribution of energy or matter, such as air, water or power.</p>
    
<blockquote>
<font size=""-1"">EXAMPLEs of distribution flow elements are ducts, pipes, wires, fittings, and equipment.</font>
</blockquote> 

<blockquote>
<font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC R2.0.<br></font>
</blockquote>


<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDistributionFlowElement</b> defines the occurrence of any distribution flow element; common information about distribution flow element types is handled by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a>.  The <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations.  The <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a> is attached using the <a href=""../../ifckernel/lexical/ifcreldefinesbytype.htm"">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute.  If the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a> has ports or aggregated elements, such objects are reflected at the <b>IfcDistributionFlowElement</b> occurrence using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Direct instantiation of <i>IfcDistributionFlowElement</i> with <i>IfcObject.ObjectType</i> asserted provides the meaning of a distribution flow element proxy.</p>
 
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Property sets may also be specified at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a>, defining the common property data for all occurrences of the same type.  They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDistributionFlowElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcDistributionFlowElement</b> override the properties defined at <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a>.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcdistributionelement.htm"">IfcDistributionElement</a> and ancestors for inherited property set definitions.</p>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElement</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionFlowElement</b> and <i>RelatedObjects</i> contains one or more components.  For example, a cable may be decomposed into wires.  Standard types for composition are defined at subtypes.</p>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElement</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href=""../../ifcproductextension/lexical/ifcspatialstructureelement.htm"">IfcSpatialStructureElement</a> (<a href=""../../ifcproductextension/lexical/ifcrelcontainedinspatialstructure.htm"">IfcRelContainedInSpatialStructure</a>) : Indicates the spatial location containing the element.</li>
<li><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>) : Indicates physical connectivity with another element (but not embedding or flow transmission), such as a light fixture hanging from a ceiling (<i>IfcCovering</i>), or a junction box having a cover plate (<i>IfcDiscreteAccessory</i>).  <i>IfcRelConnectsElements.RelatingElement</i> refers to the anchored side (ceiling for fixture, junction box for cover).</li>
<li><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a> (<a href=""../../ifcproductextension/lexical/ifcrelinterfereselements.htm"">IfcRelInterferesElements</a>) : Indicates interference with another element and precedence, such as a pipe going through a wall.</li>
<li><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcOpening</a> (<a href=""../../ifcproductextension/lexical/ifcrelfillselement.htm"">IfcRelFillsElement</a>) : Indicates embedding an element within another element (implying a cutout), such as an air terminal or junction box embedded within a wall.</li>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> (<a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a>) : Indicates ports on the element which may be connected to other elements for flow distribution of solids, liquids, gas, or electricity.  Standard port names, types, and directions are defined at subtypes.</li>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelement.htm"">IfcDistributionControlElement</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>) : Indicates a control element that senses or controls some aspect of the flow element, such as a level sensor for a tank or an actuator for a valve.</li>
</ul>
  
<p><b><u>Assignment Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElement</b> may be assigned to the following entities using relationships as indicated:</p>
<ul>
<li><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm"">IfcDistributionSystem</a> (<a href=""../../ifckernel/lexical/ifcrelassignstogroup.htm"">IfcRelAssignsToGroup</a>): Indicates a system containing interconnected devices.</li>
<li><a href=""../../ifccontrolextension/lexical/ifcperformancehistory.htm"">IfcPerformanceHistory</a> (<a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a>): Indicates realtime or historical infomation captured for the device.</li>
</ul>
<p> The <b>IfcDistributionFlowElement</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstoproduct.htm"">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionFlowElement</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href=""../../ifcprocessextension/lexical/ifctask.htm"">IfcTask</a>: Indicates tasks used to purchase, install, renovate, demolish, operate, or otherwise act upon the element.  If the element has a type, available task types are assigned to the element type.</li>
<li><a href=""../../ifcprocessextension/lexical/ifcprocedure.htm"">IfcProcedure</a>: Indicates procedures used to operate the element.  If the element has a type, available procedure types are assigned to the element type.</li>
<li><a href=""../../ifcprocessextension/lexical/ifcevent.htm"">IfcEvent</a>: Indicates events raised by the element, sequenced by procedures to be followed.  If the element has a type, available event types are assigned to the element type.</li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionFlowElement</b> is defined using one of the following entities:</p>
<ul>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm"">IfcMaterialProfileSetUsage</a>: For parametric segments, this defines the cross section and alignment to the 'Axis' representation, from which the 'Body' representation may be generated.</li>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a>: For non-parametric segments (having fixed length or path), this may define the cross section for analysis purposes, however the 'Body' representation is independently generated.</li>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>

<li>
<a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>

<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  Material information can also be given at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm"">IfcDistributionFlowElementType</a>, defining the common attribute data for all occurrences of the same type.  Standard names and material types are defined at subtypes.</p>

<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionFlowElement</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>

<ul>
<li><b>'Axis'</b>: Represents the 3D flow path of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'Curve3D' and containing a single <i>IfcBoundedCurve</i> subtype such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, or <i>IfcCompositeCurve</i>.  For elements containing directional ports (<i>IfcDistributionPort</i> with <i>FlowDirection</i> of <i>SOURCE</i> or <i>SINK</i>), the direction of the curve indicates direction of flow where a <i>SINK</i> port is positioned at the start of the curve and a <i>SOURCE</i> port is positioned at the end of the curve.  This representation is most applicable to flow segments (pipes, ducts, cables), however may be used at other elements to define a primary flow path if applicable.</li> 

<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of  'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>

<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>

<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'.  Such clearance region indicates space that should not intersect with the 'Body' representation of other elements, though may intersect with the 'Clearance' representation of other elements.  The particular use of clearance space may be for safety, maintenance, or other purpose.</li>

<li><b>'Lighting'</b>: Represents the light emission of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'LightSource' and containing one or more <i>IfcLightSource</i> subtypes.  This representation is most applicable to lamps and light fixtures, however may be used at other elements that emit light.
</ul>

<p>For all representations, if a <i>IfcDistributionFlowElement</i> occurrence is defined by a <i>IfcDistributionFlowElementType</i> having a representation of the same identifier, then 'MappedRepresentation' should be used at the occurrence unless overridden.</p>

<p>If materials are defined, geometry of each representation (most typically the 'Body' representation) may be organized into shape aspects where styles may be derived by correlating <i>IfcShapeAspect.Name</i> to a corresponding material (<i>IfcMaterialConstituent.Name</i> or <i>IfcMaterialProfile.Name</i>).</p>

<p>Representations are further defined at subtypes; for example, parametric flow segments align material profiles with the 'Axis' representation.</p>

</EPM-HTML>
"
1153;IfcFlowFitting;"<EPM-HTML>
<p>The distribution flow element <i>IfcFlowFitting</i> defines the occurrence of a junction or transition in a flow distribution system, such as an elbow or tee. Its type is defined by <i>IfcFlowFittingType</i> or its subtypes.</p>

    <blockquote>
        <font color=""#0000ff"" size=""-1"">
            HISTORY: New entity in IFC R2.0.<br>
        </font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
    </blockquote>


</EPM-HTML>
"
1154;IfcFlowSegment;"<EPM-HTML>
<p>The distribution flow element <i>IfcFlowSegment</i> defines the occurrence of a segment of a flow distribution system.</p>

<blockquote>
<font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC R2.0.<br></font>
<font color=""#ff0000"" size=""-1"">IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br></font>        
</blockquote>

<p>The <i>IfcFlowSegment</i> defines a particular occurrence of a segment inserted in the spatial context of a project. The parameters defining the type of the segment and/or its shape are defined by the <i>IfcFlowSegmentType</i>, which is related by the inverse relationship IsDefinedBy pointing to <i>IfcRelDefinesByType</i>.

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFlowSegment</b> is defined using one of the following entities:</p>
<ul>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm"">IfcMaterialProfileSetUsage</a> : for parametric segments, this defines the cross section and alignment to the 'Axis' representation, from which the 'Body' representation may be generated.</li>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm"">IfcMaterialProfileSet</a> : for non-parametric segments (having fixed length or path), this may define the cross section for analysis purposes, however the 'Body' representation is independently generated.</li>

<li><a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> : for elements containing multiple materials where profiles are not applicable, this indicates materials at named parts.</i>
</li>

<li>
<a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a> : for elements comprised of a single material where profiles are not applicable, this indicates the material.</li>
</ul>

<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  Material information can also be given at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowsegmenttype.htm"">IfcFlowSegmentType</a>, defining the common attribute data for all occurrences of the same type.  Standard names and material types are defined at subtypes.</p>


<p><b><u>Representation Use Definition</u></b></p>
<p>
Standard representations are defined at the supertype <i>IfcDistrubutionFlowElement</i>.  For parametric flow segments where <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm"">IfcMaterialProfileSetUsage</a> is defined and an 'Axis' representation is defined, then the 'Body' representation may be generated using the 'SweptSolid' or 'AdvancedSweptSolid' representation types by sweeping the profile(s) along the axis.
</p>

</EPM-HTML>
"
1155;IfcFlowController;"<EPM-HTML>
	<p>The distribution flow element <i>IfcFlowController</i> defines
    the occurrence of elements of a distribution system that 
    are used to regulate flow through a distribution system. 
    Examples include dampers, valves, switches, and relays. Its type is defined by 
    <i>IfcFlowControllerType</i> or subtypes.</p>

<blockquote>
<font color=""#0000ff"" size=""-1"">
HISTORY: New entity in IFC R2.0.<br>
</font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
</blockquote>

</EPM-HTML>
"
1156;IfcFlowTerminal;"<EPM-HTML>
<p>The distribution flow element <i>IfcFlowTerminal</i> defines the
    occurrence of a permanently attached element that acts as a terminus or 
    beginning of a distribution system (e.g., air outlet, drain, 
    water closet, sink, etc.). A terminal is typically a point
    at which a system interfaces with an external environment.
    Its type is defined by <i>IfcFlowTerminalType</i> or
    its subtypes.</p>

<blockquote>
<font color=""#0000ff"" size=""-1"">
HISTORY: New entity in IFC R2.0.<br>
</font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
</blockquote>

        
</EPM-HTML>
"
1157;IfcFlowMovingDevice;"<EPM-HTML> 
<p>The distribution flow element <i>IfcFlowMovingDevice</i> defines the occurrence of an apparatus used to distribute, circulate or perform conveyance of fluids, including liquids and gases (such as a pump or fan), and typically participates in a flow distribution system. Its type is defined by <i>IfcFlowMovingDeviceType</i> or its subtypes.</p>

<blockquote>
<font color=""#0000ff"" size=""-1"">
HISTORY: New entity in IFC R2x.<br>
</font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
</blockquote>


</EPM-HTML>
"
1158;IfcEnergyConversionDevice;"<EPM-HTML>
	<p>The distribution flow element <i>IfcEnergyConversionDevice</i> defines 
    the occurrence of a device used to perform
    energy conversion or heat transfer and typically participates
    in a flow distribution system. Its type is defined by <i>IfcEnergyConversionDeviceType</i> 
    or its subtypes.</p>


    <blockquote>
	<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC R2.0.<br>
    	</font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
    </blockquote>
    
</EPM-HTML>
"
1159;IfcFlowStorageDevice;"<EPM-HTML> 
<p>The distribution flow element <i>IfcFlowStorageDevice</i> defines
    the occurrence of a device that participates in a distribution
    system and is used for temporary storage of a fluid
    such as a liquid or a gas (e.g., tank). Its type is defined by 
    <i>IfcFlowStorageDeviceType</i> or its subtypes.</p>
    
<blockquote>
<font color=""#0000ff"" size=""-1"">
HISTORY: New entity in IFC R2x.<br>
</font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
</blockquote>

        
</EPM-HTML>
"
1160;IfcFlowTreatmentDevice;"<EPM-HTML> 
<p>The distribution flow element <i>IfcFlowTreatmentDevice</i> defines the occurrence of a device typically used to remove unwanted matter from a fluid, either liquid or gas, and typically participates in a flow distribution system.  Its type is defined by <i>IfcFlowTreatmentDeviceType</i> or its subtypes.</p>

    <blockquote>
	<font color=""#0000ff"" size=""-1"">
    	HISTORY: New entity in IFC R2x.<br>
    	</font>
	<font color=""#ff0000"" size=""-1"">
    	IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
    	</font>        
    </blockquote>
        
</EPM-HTML>
"
1161;IfcDistributionChamberElement;"<EPM-HTML>
 
<p>A distribution chamber element defines a place at which distribution systems and their constituent elements may be inspected or through which they may travel.</p>
 
<p>An <b>IfcDistributionChamberElement</b> is a formed volume used in a distribution system, such as a sump, trench or manhole. Instances of <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm"">IfcDistributionSystem</a> or <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm"">IfcDistributionFlowElement</a> may be related to the <b>IfcDistributionChamberElement</b> enabling their location in or at the chamber to be determined.</p>
 
<blockquote class=""history"">HISTORY: New entity in IFC2x2</blockquote>
 
<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDistributionChamberElement</b> defines the occurrence of any distribution chamber element; common information about distribution chamber element types is handled by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a>.  The <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations.  The <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a> is attached using the <a href=""../../ifckernel/lexical/ifcreldefinesbytype.htm"">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute.  If the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a> has ports or aggregated elements, such objects are reflected at the <b>IfcDistributionChamberElement</b> occurrence using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.</p>
 
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Property sets may also be specified at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a>, defining the common property data for all occurrences of the same type.  They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDistributionChamberElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcDistributionChamberElement</b> override the properties defined at <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a>.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm"">IfcDistributionFlowElement</a> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementCommon.xml"" target=""SOURCE"">Pset_DistributionChamberElementCommon</a></li>
</ul>
The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeFormedDuct.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeFormedDuct</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">FORMEDDUCT</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionChamber.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeInspectionChamber</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">INSPECTIONCHAMBER</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionPit.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeInspectionPit</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">INSPECTIONPIT</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeManhole.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeManhole</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">MANHOLE</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeMeterChamber.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeMeterChamber</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">METERCHAMBER</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeSump.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeSump</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">SUMP</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeTrench.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeTrench</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">TRENCH</a>)</li>
<li><a href=""../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeValveChamber.xml"" target=""SOURCE"">Pset_DistributionChamberElementTypeValveChamber</a> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm"">VALVECHAMBER</a>)</li>
</ul>
 
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionChamberElement</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  Material information can also be given at the <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm"">IfcDistributionChamberElementType</a>, defining the common attribute data for all occurrences of the same type.  The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p>
<ul>
<li><b>'Base'</b>: The material from which the base of the duct is constructed.</li>
<li><b>'Cover'</b>: The material from which the access cover to the chamber is constructed.</li>
<li><b>'Fill'</b>: The material that is used to fill the duct (where used).</li>
<li><b>'Wall'</b>: The material from which the wall of the duct is constructed.</li>
</ul>
 
</EPM-HTML>

"
1166;IfcDiscreteAccessory;"<EPM-HTML>

	 <P> <U>Definition from IAI:</U> Representation of different kinds of
		accessories included in or added to elements. </P> 
	 <BLOCKQUOTE><FONT COLOR=""#0000FF"" SIZE=""-1""> HISTORY New entity in IFC
		Release 2x2 </FONT></BLOCKQUOTE>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
</font></blockquote>

	 <P><B>General usage</B></P> 
	 <P> The exact type information of the <I>IfcDiscreteAccessory</I> is given
		in the <I>ObjectType</I> attribute inherited from <I>IfcObject</I>. Standard
		type designations are provided for guideline below. The list is not exhaustive
		and the list of definitions may be extended based on local national extensions.
		</P> 
	 <TABLE BORDER=""1""> 
		<TR> 
		  <TD><I><B>Accessory type</B></I></TD> 
		  <TD><I><B>Standard type designation</B></I></TD> 
		  <TD><I><B>Description</B></I></TD> 
		</TR> 
		<TR>
		  <TD>Shading devices:</TD>
		  <TD>'Shading device'</TD>
		  <TD>Elements specifically designed to provide shading, often fixed
			 externally and sometimes moving (e.g. by rotation)</TD>
		</TR>
		<TR> 
		  <TD>Corbels as separate components:</TD> 
		  <TD>'Hidden steel corbel'</TD> 
		  <TD>Corbel system made from steel components embedded into the master
			 element</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Visible steel corbel'</TD> 
		  <TD>Corbel system made from steel components protruding from the master
			 element</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Visible concrete corbel'</TD> 
		  <TD>Corbel system made as a separate precast concrete component added
			 to the master element</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Ladder truss connector'</TD> 
		  <TD>A fixing device in truss form with straight cross bars in ladder
			 form holding two precast conrete panels together in a sandwich wall panel.</TD>
		  
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Panel suspender'</TD> 
		  <TD>A straight fixing device holding two precast conrete panels
			 together in a sandwich wall panel.</TD> 
		</TR> 
		<TR> 
		  <TD>Electrical accessories for precast concrete elements:</TD> 
		  <TD>'Protective plug'</TD> 
		  <TD>Protective plug used in element for protecting electrical
			 accessories during manufacturing, transportation and assembly.</TD> 
		</TR> 
		<TR> 
		  <TD>Fixing parts:</TD> 
		  <TD>'Standard fixing plate'</TD> 
		  <TD>Standard fixing plate.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Edge fixing plate'</TD> 
		  <TD>Fixing plate attached to the edge of an element.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Corner fixing plate'</TD> 
		  <TD>Fixing plate attached to the corner of an element.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Slab fixing plate'</TD> 
		  <TD>Fixing plate for slabs.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Balcony hinge'</TD> 
		  <TD>Accessory supporting and fixing balconies.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Frame shoe'</TD> 
		  <TD>Fixing shoe for frames.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Thermo frame'</TD> 
		  <TD>Thermo frame.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Column shoe'</TD> 
		  <TD>Fixing shoe for columns.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Wall shoe'</TD> 
		  <TD>Fixing shoe for walls.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Fixing socket'</TD> 
		  <TD>Fixing socket.</TD> 
		</TR> 
		<TR> 
		  <TD>Joint accessories:</TD> 
		  <TD>'Neoprene bearing plate'</TD> 
		  <TD>Rubber plate used as a bearing in, for example, joints between
			 column corbels and beams.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Working joint reinforcement'</TD> 
		  <TD>Reinforcement accessory used in working joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Expansion joint reinforcement'</TD> 
		  <TD>Reinforcement accessory used in expansion joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Ribbed steel bar extension'</TD> 
		  <TD>Extension accessory made of a ribbed (reinforcement) bar used in
			 joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel pin bolt'</TD> 
		  <TD>Pin bolt used to join together, for example, columns and
			 beams.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Concrete dowel'</TD> 
		  <TD>Dowel pin used in joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Concrete groove'</TD> 
		  <TD>A groove made in a joint.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel plate'</TD> 
		  <TD>A steel plate used as an accessory in a joint.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Wire loop'</TD> 
		  <TD>A joint connector accessory made from a wire loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel loop'</TD> 
		  <TD>A joint connector accessory made from a steel bar loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Sealing strip'</TD> 
		  <TD>A strip sealing the joint.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Sealing compound'</TD> 
		  <TD>Sealing compound protecting and sealing the joint.</TD> 
		</TR> 
		<TR> 
		  <TD>Lifting accessories:</TD> 
		  <TD>'Wire lifting hook'</TD> 
		  <TD>A lifting aid in the form of a wire loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel lifting hook'</TD> 
		  <TD>A lifting aid in the form of a steel bar loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Lifting socket'</TD> 
		  <TD>A lifting aid in the form of a socket.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel lifting anchor'</TD> 
		  <TD>A lifting aid in the form of a steel lifting anchor.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Lifting hole'</TD> 
		  <TD>A lifting aid in the form of a hole.</TD> 
		</TR> 
		<TR> 
		  <TD>Accessories mainly used in the building services domain:</TD> 
		  <TD>'Antivibration'</TD> 
		  <TD>An isolating device to prevent other elements to be effected by
			 vibrations.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Drop rod'</TD> 
		  <TD>A length of material providing a hanging support to a bracket. Note
			 that a drop rod is considered to include nuts and washers required for
			 securing.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Duct foot'</TD> 
		  <TD>A base support used to receive a vertical pipe (BS6100 330 3309 -
			 duct foot).</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Framing'</TD> 
		  <TD>A frame placed around a penetration to prevent scraping against the
			 building surface or structure.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Grommet'</TD> 
		  <TD>An element placed within a penetration that seals the penetration
			 for a particular reason.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Rack'</TD> 
		  <TD>A set of shelving for the purposes of storage that may be
			 freestanding or bolted to a structure.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Safety part'</TD> 
		  <TD>A part, typically installed in vertical shafts at each level, to
			 ensure safety from falling when entering the shaft.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Sleeve'</TD> 
		  <TD>A thin barrier placed between a penetration and a penetrating
			 element.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Support section'</TD> 
		  <TD>A section of material that is used as an intermediate support upon
			 which multiple brackets can be mounted.</TD> 
		</TR> 
	 </TABLE> 

</EPM-HTML>
"
1170;IfcElementComponent;"<EPM-HTML>

<P>
An element component is a representation for minor items included in, added to or connecting to or between
   elements, which usually are not of interest from the overall building structure viewpoint.
   However, these small parts may have vital and load carrying functions within the construction.
   These items do not provide any actual space boundaries.
   Typical examples of <I>IfcElementComponent</I>s include different kinds of fasteners and various accessories.
</P>

<BLOCKQUOTE class=""history"">HISTORY New entity in IFC Release 2x2</BLOCKQUOTE>

<p>It is often desirable to model a number of same-shaped element components by means of a single
occurrence object, e.g. several bolts within a connection or a row of reinforcement elements.
In this IFC release, this is possible by means of multiple mapped representation as documented below.</p>

<p>To express the multiplicity of element components also on a higher semantic level,
an <i>IfcElementQuantity</i> should be provided via <i>IfcRelDefinesByProperties</i>.
The quantity should contain an <i>IfcQuantityCount</i> named 'Count' with the number of components.</p>

<P><B><U>Geometry Use Definition</U></B></P>

<P>
  The geometric representation of <I>IfcElementComponent</I> is given by the <I>IfcProductDefinitionShape</I>,
  allowing multiple geometric representations. Included are:
</P>

<P><B>Local Placement</B><BR>
  The local placement for <I>IfcElementComponent</I> is defined in its supertype <I>IfcProduct</I>.
  It is defined by the <I>IfcLocalPlacement</I>, which defines the local coordinate system that is
  referenced by all geometric representations. 
</P>

<UL>
  <LI>The <I>PlacementRelTo</I> relationship of <I>IfcLocalPlacement</I> shall point (if given) to
      the local placement of the same <I>IfcElement</I> or <I>IfcElementAssembly</I>, which is
      used in the <I>Decomposes</I> inverse attribute, i.e. the local placement is defined relative to
      the local placement of the element or element assembly in which the component is contained. 
  <LI>If the relative placement is not used, the absolute placement is defined within the world coordinate system. 
</UL>

<P><B>Surface Model Representation</B></P>
<P>
  Any <I>IfcElementComponent</I> (if no further constraints are defined at the level of its subtypes)
  may be represented as a single or multiple surface models, based on either shell or face based models.
  The following attribute values for the <I>IfcShapeRepresentation</I> holding this geometric representation
  shall be used:
</P>
<UL>
  <LI><I>RepresentationIdentifier</I> : 'Body'</LI>
  <LI><I>RepresentationType</I> : 'SurfaceModel'</LI>
</UL>

<P>
<B>Brep Representation</B></P>
<P>
  Any <I>IfcElementComponent</I> (if no further constraints are defined at the level of its subtypes)
  may be represented as a single or multiple Boundary Representation elements (which are restricted to faceted
  Brep with or without voids). The Brep representation allows for the representation of complex element shape.
  The following attribute values for the <I>IfcShapeRepresentation</I> holding this geometric representation
  shall be used:
</P>
<UL>
  <LI><I>RepresentationIdentifier</I> : 'Body'</LI>
  <LI><I>RepresentationType</I> : 'Brep'</LI>
</UL>

<P><B>Mapped Representation</B></P>
<P>
  The mapped item, <I>IfcMappedItem</I>, should be used if appropriate as it allows for reusing the geometry
  definition of a type at occurrences of the same type.
  The following attribute values for the <I>IfcShapeRepresentation</I> holding this geometric representation
  shall be used:
</P>
<UL>
  <LI><I>RepresentationIdentifier</I> : 'Body'</LI>
  <LI><I>RepresentationType</I> : 'MappedRepresentation'</LI>
</UL>

<p><b>Multiple Mapped Representation</b></p>

<p>A single instance of a subtype of <i>IfcElementComponent</i> can stand for several
actual element components at once.  In this case, the <i>IfcShapeRepresentation</i>
contains as many mapped items as there are element components combined within this
occurrence object:</p>

<p>Figure 151 illustrates multiple components modeled as a single occurrence object (here: <i>IfcFastener</i>)</p>
<table>
<tr><td><img src=""figures/ifcelementcomponent_multiple.png""></td></tr>
<tr><td><p class=""figure"">Figure 151 &mdash; Element component mapped representation</p></td></tr>
</table>

<p>Representation identifier and type are the same as in single mapped representation.
The number of mapped items in the representation corresponds with the count of
element components in the <i>IfcElementQuantity</i>.</p>

</EPM-HTML>"
1175;IfcElementComponentType;"<EPM-HTML>
 <P><U>Definition from IAI:</U>
    The element type (<I>IfcElementComponentType</I>) represents the supertype for element 
    types which define lists of commonly shared property set definitions of various small parts and       accessories and an optional set of product
    representations. It is used to define a supporting element mainly within 
    structural and building services domains (i.e. the specific type information  
    common to all occurrences of that type).</P> 

	 <BLOCKQUOTE><FONT COLOR=""#0000FF"" SIZE=""-1"">HISTORY New entity in IFC
		Release 2x2
		</FONT></BLOCKQUOTE>
</EPM-HTML>"
1180;IfcBuildingElementPartType;"<EPM-HTML>
<p><u>Definition from IAI:</u> The building element part type defines
lists of commonly shared property set definitions and representation maps of parts of a building element.</p>

<blockquote><font color=""#0000ff"" size=""-1"">
HISTORY New entity in IFC Release 2x4
</font></blockquote>

</EPM-HTML>
"
1188;IfcDiscreteAccessoryType;"<EPM-HTML>

	 <P><U>Definition from IAI</U>: The element type
		(<I>IfcDiscreteAccessoryType</I>) defines a list of commonly shared property
		set definitions of a discrete accessory and an optional set of product
		representations. It is used to define a supporting element mainly within
		structural and building services domains (i.e. the specific type information
		common to all occurrences of that type).</P> 
	 <P>The occurrences of the <I>IfcDiscreteAccessoryType</I> are represented
		by instances of <I>IfcDiscreteAccessory</I>.</P> 
	 <P>The <I>IfcDiscreteAccessoryType</I> is a specialization of the general
		building element component type to represent different type of structural and
		building service related auxiliary elements.</P> 
	 <BLOCKQUOTE><FONT COLOR=""#0000FF"" SIZE=""-1"">HISTORY New entity in IFC
		Release 2x2 </FONT></BLOCKQUOTE>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
</font></blockquote>

	 <P><B>General usage</B></P> 
	 <P> The exact type information of the <I>IfcDiscreteAccessoryType</I> is
		given in the <I>ElementType</I> attribute inherited from <I>IfcElementType</I>.
		Standard type designations are provided for guideline below. The list is not
		exhaustive and the list of definitions may be extended based on local national
		extensions. </P> 
	 <TABLE BORDER=""1""> 
		<TR> 
		  <TD><I><B>Accessory type</B></I></TD> 
		  <TD><I><B>Standard type designation</B></I></TD> 
		  <TD><I><B>Description</B></I></TD> 
		</TR> 
		<TR> 
		  <TD>Shading devices:</TD> 
		  <TD>'Shading device'</TD> 
		  <TD>Elements specifically designed to provide shading, often fixed
			 externally and sometimes moving (e.g. by rotation)</TD> 
		</TR> 
		<TR> 
		  <TD>Corbels as separate components:</TD> 
		  <TD>'Hidden steel corbel'</TD> 
		  <TD>Corbel system made from steel components embedded into the master
			 element</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Visible steel corbel'</TD> 
		  <TD>Corbel system made from steel components protruding from the master
			 element</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Visible concrete corbel'</TD> 
		  <TD>Corbel system made as a separate precast concrete component added
			 to the master element</TD> 
		</TR> 
		<TR> 
		  <TD>Connecting accessories, for example for sandwich wall panels:</TD> 
		  <TD>'Diagonal truss connector'</TD> 
		  <TD>A fixing device in truss form with diagonal cross bars holding two
			 precast conrete panels together in a sandwich wall panel.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Ladder truss connector'</TD> 
		  <TD>A fixing device in truss form with straight cross bars in ladder
			 form holding two precast conrete panels together in a sandwich wall panel.</TD>
		  
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Panel suspender'</TD> 
		  <TD>A straight fixing device holding two precast conrete panels
			 together in a sandwich wall panel.</TD> 
		</TR> 
		<TR> 
		  <TD>Electrical accessories for precast concrete elements:</TD> 
		  <TD>'Protective plug'</TD> 
		  <TD>Protective plug used in element for protecting electrical
			 accessories during manufacturing, transportation and assembly.</TD> 
		</TR> 
		<TR> 
		  <TD>Fixing parts:</TD> 
		  <TD>'Standard fixing plate'</TD> 
		  <TD>Standard fixing plate.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Edge fixing plate'</TD> 
		  <TD>Fixing plate attached to the edge of an element.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Corner fixing plate'</TD> 
		  <TD>Fixing plate attached to the corner of an element.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Slab fixing plate'</TD> 
		  <TD>Fixing plate for slabs.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Balcony hinge'</TD> 
		  <TD>Accessory supporting and fixing balconies.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Frame shoe'</TD> 
		  <TD>Fixing shoe for frames.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Thermo frame'</TD> 
		  <TD>Thermo frame.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Column shoe'</TD> 
		  <TD>Fixing shoe for columns.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Wall shoe'</TD> 
		  <TD>Fixing shoe for walls.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Fixing socket'</TD> 
		  <TD>Fixing socket.</TD> 
		</TR> 
		<TR> 
		  <TD>Joint accessories:</TD> 
		  <TD>'Neoprene bearing plate'</TD> 
		  <TD>Rubber plate used as a bearing in, for example, joints between
			 column corbels and beams.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Working joint reinforcement'</TD> 
		  <TD>Reinforcement accessory used in working joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Expansion joint reinforcement'</TD> 
		  <TD>Reinforcement accessory used in expansion joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Ribbed steel bar extension'</TD> 
		  <TD>Extension accessory made of a ribbed (reinforcement) bar used in
			 joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel pin bolt'</TD> 
		  <TD>Pin bolt used to join together, for example, columns and
			 beams.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Concrete dowel'</TD> 
		  <TD>Dowel pin used in joints.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Concrete groove'</TD> 
		  <TD>A groove made in a joint.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel plate'</TD> 
		  <TD>A steel plate used as an accessory in a joint.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Wire loop'</TD> 
		  <TD>A joint connector accessory made from a wire loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel loop'</TD> 
		  <TD>A joint connector accessory made from a steel bar loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Sealing strip'</TD> 
		  <TD>A strip sealing the joint.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Sealing compound'</TD> 
		  <TD>Sealing compound protecting and sealing the joint.</TD> 
		</TR> 
		<TR> 
		  <TD>Lifting accessories:</TD> 
		  <TD>'Wire lifting hook'</TD> 
		  <TD>A lifting aid in the form of a wire loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel lifting hook'</TD> 
		  <TD>A lifting aid in the form of a steel bar loop.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Lifting socket'</TD> 
		  <TD>A lifting aid in the form of a socket.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Steel lifting anchor'</TD> 
		  <TD>A lifting aid in the form of a steel lifting anchor.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Lifting hole'</TD> 
		  <TD>A lifting aid in the form of a hole.</TD> 
		</TR> 
		<TR> 
		  <TD>Accessories mainly used in the building services domain:</TD> 
		  <TD>'Antivibration'</TD> 
		  <TD>An isolating device to prevent other elements to be effected by
			 vibrations.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Drop rod'</TD> 
		  <TD>A length of material providing a hanging support to a bracket. Note
			 that a drop rod is considered to include nuts and washers required for
			 securing.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Duct foot'</TD> 
		  <TD>A base support used to receive a vertical pipe (BS6100 330 3309 -
			 duct foot).</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Framing'</TD> 
		  <TD>A frame placed around a penetration to prevent scraping against the
			 building surface or structure.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Grommet'</TD> 
		  <TD>An element placed within a penetration that seals the penetration
			 for a particular reason.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Rack'</TD> 
		  <TD>A set of shelving for the purposes of storage that may be
			 freestanding or bolted to a structure.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Safety part'</TD> 
		  <TD>A part, typically installed in vertical shafts at each level, to
			 ensure safety from falling when entering the shaft.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Sleeve'</TD> 
		  <TD>A thin barrier placed between a penetration and a penetrating
			 element.</TD> 
		</TR> 
		<TR> 
		  <TD></TD> 
		  <TD>'Support section'</TD> 
		  <TD>A section of material that is used as an intermediate support upon
			 which multiple brackets can be mounted.</TD> 
		</TR> 
	 </TABLE>



</EPM-HTML>"
1197;IfcFastenerType;"<EPM-HTML>
<P><U>Definition from IAI</U>:
    The element type (<I>IfcFastenerType</I>) defines a list of commonly shared
    property set definitions of a fastener and an optional set of product
    representations. It is used to define fasteners mainly within 
    structural and building services domains (i.e. the specific type information  
    common to all occurrences of that type).</P> 

<P>
    The occurrences of the <I>IfcFastenerType</I> are represented by
    instances of <I>IfcFastener</I>.
</P> 

<BLOCKQUOTE><FONT COLOR=""#0000FF"" SIZE=""-1"">
            HISTORY New entity in IFC Release 2x2
</FONT></BLOCKQUOTE>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
Subtype <i>IfcMechanicalFastenerType</i> redefined as direct subtype of <i>IfcElementComponentType</i>.
</font></blockquote>

<p><b><u>Property Set Use Definition</u></b></p>

<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.</p>

<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute:</p>
<ul>
<li><a href=""../../psd/IfcSharedComponentElements/Pset_FastenerWeld.xml"" target=""SOURCE"">Pset_FastenerWeld</a> (<a href=""ifcfastenertypeenum.htm"">WELD</a>)</li>
</ul>

</EPM-HTML>"
1206;IfcMechanicalFastenerType;"<EPM-HTML>

<p><u>Definition from IAI</u>: The element type (<i>IfcMechanicalFastenerType</i>) defines a list of commonly shared property set definitions of a fastener and an optional set of product representations. It is used to define mechanical fasteners mainly within structural and building services domains (i.e. the specific type information common to all occurrences of that type).</p> 

<p>The occurrences of the <i>IfcMechanicalFastenerType</i> are represented by instances of <i>IfcMechanicalFastener</i>.</p> 

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x2</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Supertype changed from <i>IfcFastenerType</i> to <i>IfcElementComponentType</i>.
Attributes <i>PredefinedType</i>, <i>NominalDiameter</i>, <i>NominalLength</i> added.
</font></blockquote>

<p>Mechanical fasteners, especially bolts, are often standardized.  To refer to a formal fastener
designation according to a standard (a product norm), <i>IfcRelAssociatesClassification</i> together
with <i>IfcClassificationReference</i> should be used.</p>
<ul>
<li><i>IfcClassificationReference.ItemReference</i>
contains a machine-readable form of the formal fastener designation from the norm.
Example: 'M16X80-10.9-HV' for a high-strength structural bolting assembly for preloading with
hexagon bolt and nut.  (On the other hand, <i>IfcMechanicalFastenerType.Name</i> contains a
displayable name which may not necessarily be the same as the formal designation.)</li>
<li><i>IfcClassificationReference.Name</i> carries the short name of the fastener norm.
Example: 'EN 14399-4' as the respective European standard for high-strength hexagon bolts.</li>
<li>Optionally, the norm can be further described by
<i>IfcClassificationReference.ReferencedSource</i>, including information like publisher and
date of issue of the norm.</li>
</ul>

<p>Furthermore, <i>IfcRelAssociatesLibrary</i> together with <i>IfcLibraryReference</i> may be
used to refer to a library which contains fastener definitions.</p>

<p><b><u>Property Set Use Definition</u></b></p>

<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.</p>

<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute:</p>
<ul>
<li><a href=""../../psd/IfcSharedComponentElements/Pset_MechanicalFastenerBolt.xml"" target=""SOURCE"">Pset_MechanicalFastenerBolt</a> (<a href=""ifcmechanicalfastenertypeenum.htm"">BOLT</a>)</li>
</ul>

</EPM-HTML>"
1224;IfcFastener;"<EPM-HTML>
<P>
<U>Definition from IAI:</U>
   Representations of fixing parts which are used as fasteners to connect or join elements with 
   other elements.
</P>

<BLOCKQUOTE><FONT COLOR=""#0000FF"" SIZE=""-1"">
   HISTORY New entity in IFC Release 2x2
</FONT></BLOCKQUOTE>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
</font></blockquote>

</EPM-HTML>
"
1228;IfcBuildingElementPart;"<EPM-HTML>
<p><u>Definition from IAI:</u> Layers or major components as subordinate
parts of a building element. Typical usage examples include precast concrete
sandwich walls, where the layers may have different geometry representations.
In this case the layered material representation does not sufficiently describe
the element. Each layer is represented by an own instance of the
<i>IfcBuildingElementPart</i> with its own geometry description.</p>

<p>The kind of building element part is further specified by a
corresponding instance of <i>IfcBuildingElementPartType</i>,
referred to by <i>IfcRelDefinesByType</i>.</p>

<blockquote><font color=""#0000ff"" size=""-1"">
HISTORY New entity in IFC Release 2x2
</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Moved from from <i>IfcStructuralElementsDomain</i> schema to
<i>IfcSharedComponentElements</i> schema, compatible change of supertype,
attribute <i>PredefinedType</i> added.
</font></blockquote>

</EPM-HTML>
"
1232;IfcMechanicalFastener;"<EPM-HTML>

<p><u>Definition from IAI:</u> Fasteners connecting building elements mechanically.  A single instance of this class may represent one or many of actual mechanical fasteners, for example an array of bolts or a row of nails.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY New entity in IFC Release 2x2</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:
Supertype changed from <i>IfcFastener</i> to <i>IfcElementComponent</i>.
Attribute <i>PredefinedType</i> added.
Attributes <i>NominalDiameter</i> and <i>NominalLength</i> moved to <i>IfcMechanicalFastenerType</i>.
</font></blockquote>

<p><u><b>Geometry Use Definition</b></u></p>

<p>See definitions at the supertype <i>IfcElementComponent</i>.</p>

<p>In addition, a symbolic representation is defined for a row of fasteners or several rows of
fasteners within a single instance of <i>IfcMechanicalFastener</i>.  Such rows or arrays may
contain possibly large numbers of individual pieces.  The product definition shape consists of
an <i>IfcShapeRepresentation</i> with the attribute values</p>
<ul>
  <li><i>RepresentationIdentifier</i> : 'Row'</li>
  <li><i>RepresentationType</i> : 'GeometricCurveSet'</li>
</ul>
<p>and one or several curves as geometric items.  The curves represent where the heads of the fasteners
are located.  The local placement of the <i>IfcMechanicalFastener</i> shall be located and oriented such
that the local z axis is parallel with the axes of the fasteners (bolts, nails, staples or similar).</p>

<p>In case of such a symbolic 'Row' representation, an <i>IfcElementQuantity</i> should be attached to
the <i>IfcMechanicalFastener</i> via <i>IfcRelDefinesByProperties</i>.  The quantity should contain an
<i>IfcQuantityCount</i> named 'Count' with the number of fasteners and an <i>IfcQuantityLength</i>
named 'Spacing' which expresses the center-to-center distances of fasteners.</p>

</EPM-HTML>
"
1237;IfcRelCoversSpaces;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The objectified relationship,
      <i>IfcRelCoversSpace</i>, relates˙a space object to one or
      many coverings, which faces (or is assigned to) the space.
    </p>
    <blockquote>
      <p>
        <small>NOTE Particularly floorings, ceilings and wall
        coverings, such as claddings or tiling are often
        considered as space coverings, rather then wall or slab
        coverings. In some life cycle phases, such as the
        operation phase, the relationship is always made to the
        space.</small>
      </p>
    </blockquote>
    <p>
      The IFC specification provides two relationships:
    </p>
    <ul>
      <li>
        <i>IfcRelCoversBldgElements</i> to assign coverings to
        elements, and
      </li>
      <li>
        <i>IfcRelCoversSpaces</i> to assign coverings to spaces
      </li>
    </ul>
    <p>
      Which relationship should be applied has to be determined
      by the context of the project or application .
    </p>
    <blockquote>
      <p>
        <small>NOTE View definition may determine the necessity
        to use either of the two relationship elements</small>
      </p>
    </blockquote>
    <blockquote>
      <small><font color=""#0000FF"">HISTORY˙ New Entity in Release
      IFC 2x Edition 3.</font></small>
    </blockquote>
</EPM-HTML>"
1240;IfcRelConnectsPathElements;"<EPM-HTML>
<p>The
<i>IfcRelConnectsPathElements</i> relationship provides the connectivity information between two elements, which have path information.</p>

<p>The objectified relationship provides the additional
information required to describe the connection between two path
based elements that might have single or multiple layers of
material. The connection type specifies where at the path based
element a connection is given (at the start, in the middle or at
the end).</p>

<p>The connection is described by a connection geometry, given
within the object coordinate systems of the
<i>RelatingElement</i> and of the <i>RelatedElement</i>. In case
of <i>IfcWallStandardCase</i> as the <i>RelatingElement</i> and
<i>RelatedElement</i> the connection geometry is provided by the
subtype <i>IfcConnectionCurveGeometry</i>. Both curves indicate
the so called ""end cap"", i.e. the curve that trims the wall outer
edges (being parallel along the wall axis) at the end.</p>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.5.</blockquote>

<p>Figure 115 shows the application of <i>IfcRelConnectsPathElements</i> with the <i>ConnectionGeometry</i> of type <i>IfcConnectionCurveGeometry</i>. The example shows the connection relationship between two instances of <i>IfcWallStandardCase</i> using the <i>IfcRelConnectsPathElements</i> relationship. The <i>ConnectionCurveGeometry</i> defines the <i>CurveOnReleatingElement</i> and <i>CurveOnRelatedElement</i>, both are of type <i>IfcPolyline</i>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td valign=""top"" align=""left"" width=""410""><img src=""figures/IfcRelConnectsPathElements-fig1.png"" alt=""wall connection"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 115 &mdash; Path connection geometry</p><td></tr>
</table>

<p>Figure 116 illustrates using the <i>IfcRelConnectsPathElements</i> for a ""T"" type connection between two instances of <i>IfcWallStandardCase</i>.</p>
<p>Figure 117 illustrates using the <i>IfcRelConnectsPathElements</i> for a ""L"" type connection between two instances of <i>IfcWallStandardCase</i>.</p>
<blockquote class=""note"">NOTE&nbsp; The two wall axes connect in each case.</blockquote>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top"">
<td valign=""top"" align=""left"" width=""410""><img src=""figures/IfcRelConnectsPathElements-fig3.png"" alt=""wall connection"" width=""400"" height=""260"" border=""0""></td>
<td valign=""top"" align=""left"">˙<img src=""figures/IfcRelConnectsPathElements-fig2.png"" alt=""wall connection"" width=""320"" height=""200"" border=""0""></td>
</tr>
<tr valign=""top"">
<td valign=""top"" align=""left"" width=""400""><p class=""figure"">Figure 116 &mdash; Path connection T-Type</p></td>
<td valign=""top"" align=""left"" width=""320""><p class=""figure"">Figure 117 &mdash; Path connection L-Type</p></td>
</tr>
</table>

</EPM-HTML>"
1250;IfcBeam;"<EPM-HTML> 

<p><u>Definition from ISO 6707-1:1989</u>: Structural member designed to carry loads between or beyond points of support, usually narrow in relation to its length and horizontal or nearly so.</p>

<p>An <i>IfcBeam</i> is a horizontal, or nearly horizontal, structural member that is capable of withstanding load primarily by resisting bending. It represents such a member from an architectural point of view. It is not required to be load bearing.</p>

<blockquote class=""note"">NOTE &nbsp;The representation of a beam in a structural analysis model is provided by
<i>IfcStructuralCurveMember</i> being part of an <i>IfcStructuralAnalysisModel</i>.</blockquote>

<blockquote class=""note"">NOTE &nbsp;For any longitudial structural member, not constrained to be predominately horizontal nor vertical, or where this semantic information is irrelevant, the entity <i>IfcMember</i> should be used.</blockquote>

<p>The IFC specification provides two entities for beam occurrences:</p>
<ul>
<li><i>IfcBeamStandardCase</i> used for all occurrences of beams, that have a profile defined that is swept along a directrix. The profile might be changed uniformly by a taper definition along the directrix. The profile parameter and its cardinal point of insertion can be fully described by the <i>IfcMaterialProfileSetUsage</i>. These beams are always represented geometricly by an 'Axis' and a 'SweptSolid' or 'AdvancedSweptSolid' shape representation (or by a 'Clipping' geometry based on the swept solid), if a 3D geometric representation is assigned. In addition they have to have a corresponding <i>IfcMaterialProfileSetUsage</i> assigned.
<blockquote class=""note"">NOTE&nbsp; View definitions and implementer agreements may further constrain the applicable geometry types, for example, by excluding tapering from an <i>IfcBeamStandardCase</i> implementation.</blockquote>
</li>
<li><i>IfcBeam</i> used for all other occurrences of beams, particularly for beams with changing profile sizes along the extrusion, or beams defined by non-linear extrusion, or beams having only 'Brep', or 'SurfaceModel' geometry.</li>
</ul>

<blockquote class=""history"">HISTORY New entity in IFC Release 1.0</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcBeam</i> defines the occuurence of any beam, common
information about beam types (or styles) is handled by
<i>IfcBeamType</i>. The <i>IfcBeamType</i> (if present) may
establish the common&nbsp;type name, usage (or predefined) type,
common material layer set, common set of properties and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcBeamType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcBeamType</i> is attached (i.e. if only occurrence
information is given) the <i>PredefinedType</i> should be provided.
If set to .USERDEFINED. a user defined value can be provided by the
<i>ObjectType</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcBeam</i> is defined by the
<i>IfcMaterialProfileSet</i> or as fallback by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.</p>
<blockquote><small>Note It is illegal to assign an
<i>IfcMaterialProfileSetUsage</i> to an <i>IfcBeam</i>. Only the
subtype <i>IfcBeamStandardCase</i> supports this
concept.</small></blockquote>
<p>Material information can also be given at the
<i>IfcBeamType</i>, defining the common attribute data for all
occurrences of the same type. It is then accessible by the inverse
<i><font color=""#0000FF"">IsTypedBy</font></i> relationship pointing
to <i>IfcBeamType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterialProfileSet</i> or <i>IfcMaterial</i>. If both are
given, then the material directly assigned to <i>IfcBeam</i>
overrides the material assigned to <i>IfcBeamType</i>.</p>
<p><u><b>Property Set Use Definition</b></u></p>
<p>The property sets relating to the <i>IfcBeam</i> are defined by
the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcBeam</i> are part of this IFC
release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_BeamCommon.xml""
target=""SOURCE"">Pset_BeamCommon</a>: common property set for all
beam occurrences</li>
</ul>
<p>Property sets can also be given at the <i>IfcBeamType</i>,
defining the common property data for all occurrences of the same
type. It is then accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcBeamType.HasPropertySets</i>. If both are given, then the
properties directly assigned to <i>IfcBeam</i> overrides the
properties assigned to <i>IfcBeamType</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcBeam</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities
can be defined being subjected to local standard of measurement
with another string value assigned to <i>MethodOfMeasurement</i>.
Quanties shall be never assigned to the <i>IfcBeamType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_BeamBaseQuantities.xml""
target=""SOURCE"">Qto_BeamBaseQuantities</a>: base quantities for all
beam occurrences.</li>
</ul>

<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcBeam</i>, as any subtype of <i>IfcBuildingElement</i>,
may participate in two different containment relationships. The
first (and in most implementation scenarios mandatory) relationship
is the hierachical spatial containment, the second (optional)
relationship is the aggregation within an element assembly.</p>
<ul>
<li>The <i>IfcBeam</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of <i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcBeam</i> may be aggregated into an element assembly
using the objectified relationship <i>IfcRelAggregates</i>,
refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this case
it should not be additionally contained in the project spatial
hierarchy, i.e. <i>SELF\IfcElement.ContainedInStructure</i> should
be <i>NIL.</i></li>
</ul>

<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcBeam</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcBeam</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to a
spatial structure element at a higher level, referenced by that.
<ul>
<li>Exception: If the <i>IfcBeam</i> is part of an assembly, the
<i>PlacementRelTo</i> relationship of <i>IfcLocalPlacement</i>
shall point to the local placement of the container element, e.g.
<i>IfcElementAssembly</i>,</li>
</ul>
</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the <font color=""#0000FF"">'Axis'</font>, 'Body', and
'Box' representations are supported. The 'Box' representation
includes the representation type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcBeam</i> is defined
using the 'Axis' representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', 'Curve3D'</li>
</ul>
<blockquote><small>The 'Axis' can be used to represent the system
axis and length of a beam that may extent the body
length.</small></blockquote>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcBeam</i> can be represented
using the representation types 'SweptSolid', 'Clipping',
'AdvancedSweptSolid', 'MappedRepresentation', 'SurfaceModel', and
'Brep'. The representation types 'SurfaceModel' and 'Brep' are
explained at <i>IfcBuildingElement</i>.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i>,
<i>IfcRevolvedAreaSolid</i> shall be supported</li>
<li><u>Profile</u>: all subtypes of <i>IfcProfileDef</i> (with
exception of <i>IfcArbitraryOpenProfileDef</i>)</li>
<li><u>Extrusion</u>:&nbsp; All extrusion directions shall be
supported.</li>
</ul>

<p>Figure 71 illustrates the 'SweptSolid' geometric representation.  There are no restrictions or conventions on how to use the local placement (black), solid of extrusion placement (red) and profile placement (green).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBeam_Standard-Layout1.gif"" alt=""standard beam"" border=""0"" height=""299"" width=""393""></td></tr>
<tr><td><p class=""figure"">Figure 71 &mdash; Beam swept solid</p></td></tr>
</table>

<p>Figure 72 illustrates the use of non-perpendicular extrusion to create the <i>IfcExtrudedAreaSolid</i>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcBeam_Advanced-1-Layout1.gif"" alt=""non-perpendicular extrusion"" border=""0"" height=""299"" width=""393""></td></tr>
<tr><td><p class=""figure"">Figure 72 &mdash; Beam non-perpendicular extrusion</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' geometric representation</li>
<li><u>Profile</u>: see 'SweptSolid' geometric representation</li>
<li><u>Extrusion</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i> (or its subtypes).</li>
</ul>

<p>Figure 73 illustrates use of <i>IfcBooleanClippingResult</i> between an <i>IfcExtrudedAreaSolid</i> and an <i>IfcHalfSpaceSolid</i> to create a clipped body.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBeam_Advanced-2-Layout1.gif"" alt=""clipped beam"" border=""0"" height=""299"" width=""393""></td></tr>
<tr><td><p class=""figure"">Figure 73 &mdash; Beam clipping</p></td></tr>
</table>

<p><i>AdvancedSweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedSweptSolid'</li>
</ul>
<p>The following additional constraints apply to the
'AdvancedSweptSolid' representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcSurfaceCurveSweptAreaSolid</i>,
<i>IfcFixedReferenceSweptAreaSolid</i>,
<i>IfcExtrudedAreaSolidTapered</i>,
<i>IfcRevolvedAreaSolidTapered</i> shall be supported.
<blockquote><small>NOTE View definitions and implementer agreement
can further constrain the allowed swept solid
types.</small></blockquote>
</li>
<li><u>Profile</u>: see 'SweptSolid' geometric representation</li>
<li><u>Extrusion</u>: not applicable</li>
</ul>
<p><i>MappedRepresentation Representation Type</i></p>
<p>The 'MappedRepresentation' representation is supported as it
allows for reusing the geometry definition of the beam type at all
occurrences of the same type. The following attribute values for
the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for the 'SweptSolid', 'Clipping',
'AdvancedSweptSolid', 'SurfaceModel', and 'Brep' geometric
representation, shall apply to the <i>MappedRepresentation</i> of
the <i>IfcRepresentationMap</i>.</p>
</EPM-HTML>"
1255;IfcBeamStandardCase;"<EPM-HTML>
<p>The standard beam,
<i>IfcBeamStandardCase</i>, defines a beam with certain constraints
for the provision of material usage, parameters and with certain
constraints for the geometric representation. The
<i>IfcBeamStandardCase</i> handles all cases of beams, that:</p>
<ul>
<li>have a reference to the <i>IfcMaterialProfileSetUsage</i>
defining the material profile association of the beam with the
cardinal point of its insertion relative to the local
placement.</li>
<li>are consistent in using the correct cardinal point offset of
the profile as compared to the 'Axis' and 'Body' shape
representation</li>
<li>are based on a sweep of a planar profile, or set of profiles,
as defined by the <i>IfcMaterialProfileSet</i></li>
<li>have an 'Axis' shape representation with constraints provided
below in the geometry use definition</li>
<li>have a 'Body' shape representation with constraints provided
below in the geometry use definition
<ul>
<li>are extruded perpendicular to the profile definition plane</li>
<li>have a start profile, or set of profiles, that is swept</li>
<li>the sweeping operation can be linear extrusion, circular
rotation, or a sweep along a directrix</li>
<li>the start profile, or set of profiles can be swept unchanged,
or might be changed uniformly by a taper definition</li>
</ul>
</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE&nbsp; View definitions and implementer
agreements may further constrain the applicable geometry types,
e.g. by excluding tapering from an <i>IfcBeamStandardCase</i>
implementation.</small></blockquote>
</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC2x4.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcBeam</i> defines the occurrence of any beam, common
information about beam types (or styles) is handled by
<i>IfcBeamType</i>. The <i>IfcBeamType</i> (if present) may
establish the common type name, usage (or predefined) type, common
set of properties, and common material profile set (combining
profiles and material of profile). The <i>IfcBeamType</i> is
attached using the <i>IfcRelDefinedByType.RelatingType</i>
objectified relationship and is accessible by the inverse
<span style=""color:#0000ff""><i>IsTypedBy</i></span> attribute.</p>
<p>The <i>IfcBeamStandardCase</i> defines in addition that the
<i>IfcBeamType</i> should have a unique
<i>IfcMaterialProfileSet</i>, that is referenced by the
<i>IfcMaterialProfileSetUsage</i> that is assigned to all
occurrences of this beam type.</p>

<p>Figure 74 illustrates assignment of <i>IfcMaterialProfileSetUsage</i> and <i>IfcMaterialProfileSet</i> to the <i>IfcBeamStandardCase</i> as the beam occurrence and to the <i>IfcBeamType</i>. The same <i>IfcMaterialProfileSet</i> shall be shared by many occurrences of <i>IfcMaterialProfileSetUsage</i>. This relationship shall be consistent to the relationship between the <i>IfcBeamType</i> and the <i>IfcBeamStandardCase</i>.</p>

<table>
<tr><td><img alt=""Material profile set and usage"" src=""figures/IfcBeamStandardCase-01.png"" height=""500"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 74 &mdash; Beam profile usage</p></td></tr>
</table>

<p>Figure 75 illustrates alignment of cardinal points.</p>
<blockquote class=""note"">NOTE&nbsp; It has to be guaranteed that the use of <i>IfcCardinalPointEnum</i> is consistent to the placement of the extrusion body provided by <i>IfcExtrudedAreaSolid.Position</i></blockquote>
<blockquote class=""note"">NOTE&nbsp; The cardinal points <b>8</b> (top centre) and <b>6</b> (mid-depth right) are assigned according to the definition at <i>IfcCardinalPointReference</i></blockquote>

<table>
<tr><td><img alt=""Cardinal point usage"" src=""figures/IfcBeamStandardCase_CardinalPoint.png"" height=""250"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 75 &mdash; Beam cardinal points</p></td></tr>
</table>

<p>Figure 76 illustrates assignment of a composite profile by using <i>IfcCompositeProfile</i> for geometric representation and several <i>IfcMaterialProfile</i>'s within the <i>IfcMaterialProfileSet</i>.</p>

<table>
<tr><td><img alt=""Material profile set and usage"" src=""figures/IfcBeamStandardCase-02.png"" height=""550"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 76 &mdash; Beam composite profiles</p></td></tr>
</table>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcBeamStandardCase</i> is defined by
<i>IfcMaterialProfileSetUsage</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Composite profile beams can be represented by refering to several
<i>IfcMaterialProfile</i>'s within the <i>IfcMaterialProfileSet</i>
that is referenced from the <i>IfcMaterialProfileSetUsage</i>. See
<b>Type Use Definition</b> for additional agreements for material
assignement to <em>IfcBeamStandardCase</em> and
<em>IfcBeamType</em>.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcBeamStandardCase</i> are
defined at the supertype <i>IfcBeam</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcBeamStandardCase</i> are
defined at the supertype <i>IfcBeam</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcBeamStandardCase</i> are defined at the supertype
<i>IfcBeam</i>.</p>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcBeamStandardCase</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The general use of local placement is defined at the supertype
<i>IfcBeam</i>. The following restriction is imposed:</p>
<ul>
<li>The local placement shall provide the location and directions
for the standard beam, the x/y plane is the plane for the start
profile, and the z-axis is the extrusion axis for the beam body (in
case of rotation, the tangent direction).</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>The geometric representation of <i>IfcBeamStandardCase</i> is
defined using the following multiple shape representations for its
definition:</p>
<ul>
<li><u>Axis</u>: A three dimensional open curve (subtype of
<i>IfcBoundedCurve</i>) defining the axis for the standard beam.
The cardinal point is determined by the beam axis.</li>
<li><u>Body</u>: A Swept Solid Representation or a CSG clipping
representation defining the 3D shape of the standard beam.</li>
</ul>
<blockquote><small>NOTE It is invalid to exchange a 'SurfaceModel',
'Brep', or 'MappedRepresentation' representation for the 'Body'
shape representation of an
<i>IfcBeamStandardCase</i>.</small></blockquote>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcBeamStandardCase</i>
is defined using the 'Axis' representation. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve3D'</li>
</ul>
<p>The following additional constraints apply to the 'Axis'
representation, if the 'Body' shape representation has the
<i>RepresentationType</i> : 'SweptSolid':</p>
<ul>
<li><i>Axis</i> :
<ul>
<li><i>IfcPolyline</i> having two <i>Points</i>, or
<i>IfcTrimmedCurve</i> with <i>BasisCurve</i> of Type
<i>IfcLine</i> for 'SweptSolid' provided as
<em>IfcExtrudedAreaSolid</em>. The axis curve lies on the z axis of
the object coordinate system.</li>
<li><i>IfcTrimmedCurve</i> with <i>BasisCurve</i> of Type
<i>IfcCircle</i> for 'SweptSolid' provided as
<em>IfcRevolvedAreaSolid</em>. The axis curve lies on the x/z plane
of the object coordinate system, the tangent at the start is along
the positive z-axis.</li>
</ul>
</li>
</ul>

<p>As shown in Figure 77, the axis shall be defined along the z axis of the object coordinate system. The axis representation can be used to represent the system length of a beam that may extent the body length of the beam.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""Axis"">
<tr><td align=""left"" valign=""top"" width=""350""><img src=
""figures/IfcBeamStandardCase_Axis-01.png"" alt=""Axis"" height=""300"" width=""400"" border=""1""></td></tr>
<tr><td><p class=""figure"">Figure 77 &mdash; Beam axis representation</p></td></tr>
</table>

<p>As shown in Figure 78, the axis representation shall be used to represent the cardinal point as the offset between the 'Axis' and the extrusion path of the beam. The extrusion path is provided as <i>IfcExtrudedAreaSolid.ExtrudedDirection</i> and should be parallel to the 'Axis' and the z axis. It has to be guaranteed that the value provided by
<i>IfcMaterialProfileSetUsage.CardinalPoint</i> is consistent to the <i>IfcExtrudedAreaSolid.Position</i>.</p>

<table>
<tr><td align=""left"" valign=""top"" width=""350""><img src=""figures/IfcBeamStandardCase_Axis-02.png"" alt=""Axis"" height=""300""
width=""400"" border=""1""></td></tr>
<tr><td><p class=""figure"">Figure 78 &mdash; Beam axis cardinal point</p></td></tr>
</table>

<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcBeamStandardCase</i> can be
represented using the representation types 'SweptSolid',
'Clipping', or 'AdvancedSweptSolid'.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i>,
<i>IfcRevolvedAreaSolid</i> shall be supported</li>
<li><u>Solid Position</u> : The <em>IfcSweptAreaSolid.Position</em>
shall exclusively been used to correspond to the cardinal point.
The x/y offset of the <em>Position</em> represents the cardinal
point offset of the profile against the axis. No rotation shall be
allowed.</li>
<li><u>Profile</u>: All subtypes of
<i>IfcParameterizedProfileDef</i></li>
<li><u>Profile Position</u> : For all single profiles, the
<i>IfcParameterizedProfileDef.Position</i> shall be NIL, or having
<i>Location</i> = 0.,0. and <i>RefDirection</i> = 1.,0.</li>
<li><u>Extrusion</u>:&nbsp;Perpendicular to the profile direction.
The <i>IfcExtrudedAreaSolid.ExtrudedDirection</i> shall be
[0.,0.,1.].</li>
<li><u>Orientation</u>: The y-axis of the profile, as determined by
<i>IfcSweptAreaSolid.Position.P[2]</i> shall point upwards. It
indicates the ""role"" of the beam, a role=0&deg; means y-axis of
profile pointing upwards.</li>
</ul>

<p>Figure 79 illustrates a standard geometric representation with cardinal point applied as <b>1</b> (bottom left).</p>
<p>The following interpretation of dimension parameter applies for rectangular beams with linear extrusions:</p>
<ul>
<li><i>IfcRectangleProfileDef.YDim</i> interpreted as beam height</li>
<li><i>IfcRectangleProfileDef.XDim</i> interpreted as beam width</li>
</ul>
<p>The following interpretation of dimension parameter applies for circular beams:</p>
<ul>
<li><i>IfcCircleProfileDef.Radius</i> interpreted as beam radius.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBeamStandardCase_SweptSolid-01.png"" alt=""standard beam"" border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 79 &mdash; Beam body extrusion</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the 'Clipping'
representation:</p>
<ul>
<li><u>Solid</u> : see 'SweptSolid' geometric representation</li>
<li><u>Solid Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Profile</u> : see 'SweptSolid' geometric representation</li>
<li><u>Profile Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Orientation</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i> (or its subtypes).</li>
</ul>

<p>Figure 80 illustrates a 'Clipping' geometric representation with use of <i>IfcBooleanClippingResult</i> between an <i>IfcExtrudedAreaSolid</i> and an <i>IfcHalfSpaceSolid</i> to create a clipped body, with cardinal point applied as <b>4</b> (mid-depth left)</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBeamStandardCase_Clipping-01.png"" alt=""clipped beam""
border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 80 &mdash; Beam body clipping</p></td></tr>
</table>

<p><i>AdvancedSweptSolid Representation Type</i></p>
<p>The 'AdvancedSweptSolid' representation type is a valid body
representation of <i>IfcBeamStandardCase</i>. The following
attribute values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedSweptSolid'</li>
</ul>
<p>The following additional constraints apply to the
'AdvancedSweptSolid' representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcSurfaceCurveSweptAreaSolid</i>,
<i>IfcFixedReferenceSweptAreaSolid</i>,
<i>IfcExtrudedAreaSolidTapered</i>,
<i>IfcRevolvedAreaSolidTapered</i> shall be supported.
<blockquote><small>NOTE View definitions and implementer agreement
can further constrain the allowed swept solid
types.</small></blockquote>
</li>
<li><u>Solid Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Profile</u>: see 'SweptSolid' geometric representation</li>
<li><u>Profile Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:&nbsp;not applicable</li>
</ul>

</EPM-HTML>"
1266;IfcColumn;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Structural member of
slender form, usually vertical, that transmits to its base the
forces, primarily in compression, that are applied to it.</p>
<p><An <i>IfcColumn</i> is a vertical
structural member which often is aligned with a structural grid
intersection. It represents a vertical, or nearly vertical,
structural member that transmits, through compression, the weight
of the structure above to other structural elements below. It
represents such a member from an architectural point of view. It
is not required to be load bearing.</p>
<blockquote><small>NOTE The representation of a column in a
structural analysis model is provided by
<i>IfcStructuralCurveMember</i> being part of an
<i>IfcStructuralAnalysisModel</i>.</small><br>
<br>
<small>NOTE ˙For any longitudial structural member, not
constrained to be predominately horizontal nor vertical, or where
this semantic information is irrelevant, the entity
<i>IfcMember</i> exists.</small></blockquote>
<p>The IFC specification provides two entities for column
occurrences:</p>
<ul>
<li><i>IfcColumnStandardCase</i> used for all occurrences of
columns, tthat have a profile defined that is swept along a
directrix. The profile might be changed uniformly by a taper
definition along the directrix. The profile parameter and its
cardinal point of insertion can be fully described by the
<i>IfcMaterialProfileSetUsage</i>. These beams are always
represented geometricly by an 'Axis' and a 'SweptSolid' or
'AdvancedSweptSolid' shape representation (or by a 'Clipping'
geometry based on the swept solid), if a 3D geometric
representation is assigned. In addition they have to have a
corresponding <i>IfcMaterialProfileSetUsage</i> assigned.
<blockquote><small>NOTE˙ View definitions and implementer
agreements may further constrain the applicable geometry types,
e.g. by excluding tapering from an <i>IfcColumnStandardCase</i>
implementation.</small></blockquote>
</li>
<li><i>IfcColumn</i> used for all other occurrences of columns,
particularly for columns with changing profile sizes along the
extrusion, or columns defined by non-linear extrusion, or columns
having only 'Brep', or 'SurfaceModel' geometry.</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcColumn</i> defines the occuurence of any column, common
information about column types (or styles) is handled by
<i>IfcColumnType</i>. The <i>IfcColumnType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material layer set, common set of properties and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcColumnType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcColumnType</i> is attached˙(i.e. if only
occurrence information is given) the <i>PredefinedType</i> should
be provided. If set to .USERDEFINED. a user defined value can be
provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcColumn</i> is defined by the
<i>IfcMaterialProfileSet</i> or as fallback by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterialProfileSetUsage</i> to an <i>IfcColumn</i>. Only
the subtype <i>IfcColumnStandardCase</i> supports this
concept.</small></blockquote>
<p>Material information can also be given at the
<i>IfcColumnType</i>, defining the common attribute data for all
occurrences of the same type.˙It is then accessible by the
inverse <i><font color=""#0000FF"">IsTypedBy</font></i>
relationship pointing to
<i>IfcColumnType</i><i>.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterialProfileSet</i> or <i>IfcMaterial</i>. If both are
given, then the material directly assigned to <i>IfcColumn</i>
overrides the material assigned to <i>IfcColumnType</i>.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcColumn</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcColumn</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_ColumnCommon.xml"" target=
""SOURCE"">Pset_ColumnCommon</a>: common property set for all
column occurrences</li>
</ul>
<p>Property sets can also be given at the <i>IfcColumnType</i>,
defining the common property data for all occurrences of the same
type.˙It is then accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcColumnType.HasPropertySets</i>. If both are given, then the
properties directly assigned to <i>IfcColumn</i> overrides the
properties assigned to <i>IfcColumnType</i>.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcColumn</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. It is accessible by the inverse
<i>IsDefinedBy</i> relationship. The following base quantities
are defined and should be exchanged with the
<i>IfcElementQuantity.MethodOfMeasurement</i> = 'BaseQuantities'.
Other quantities can be defined being subjected to local standard
of measurement with another string value assigned to <i>Name</i>
and a value provided for <i>MethodOfMeasurement</i>. Quanties
shall be never assigned to the <i>IfcColumnType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_ColumnBaseQuantities.xml""
target=""SOURCE"">Qto_ColumnBaseQuantities</a>: base quantities for
all column occurrences.</li>
</ul>

<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcColumn</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcColumn</i>, is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcColumn</i>, may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>

<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcColumn</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcColumn</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to
a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the <font color=""#0000FF"">'Axis'</font>, 'Body',
and 'Box' representations are supported. The 'Box' representation
includes the representation type 'BoundingBox' and is explained
at <i>IfcBuildingElement</i>.</p>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcColumn</i> is
defined using the 'Axis' representation. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', 'Curve3D'</li>
</ul>
<p>The axis representation can be used to represent the system
length of a column that may extent the body length of the
column.</p>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcColumn</i> can be represented
using the representation types 'SweptSolid', 'Clipping',
'AdvancedSweptSolid', 'MappedRepresentation', 'SurfaceModel', and
'Brep'. The representation types 'SurfaceModel' and 'Brep' are
explained at <i>IfcBuildingElement</i>.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i>,
<i>IfcRevolvedAreaSolid</i> shall be supported</li>
<li><u>Profile</u>: all subtypes of <i>IfcProfileDef</i> (with
exception of <i>IfcArbitraryOpenProfileDef</i>)˙</li>
<li><u>Extrusion</u>:˙All extrusion directions shall be
supported</li>
</ul>

<p>Figure 81 illustrates a 'SweptSolid' geometric representation. There are no restrictions or conventions on
how to use the local placement (black), solid of extrusion placement (red) and profile placement (green).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""420""><img src=""figures/IfcColumn_Standard-Layout1.gif"" alt=""standard column"" border=""0"" height=""290"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 81 &mdash; Column swept solid</p></td></tr>
</table>

<p>Figure 82 illustrates use of a special profile type (here <i>IfcIShapeProfileDef</i>) for the definition of the <i>IfcExtrudedAreaSolid</i>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top"" width=""420""><img src=""figures/IfcColumn_Advanced-1-Layout1.png"" alt=""advanced column"" border=""0"" height=""292"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 82 &mdash; Column extrusion of I-Shape</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' geometric representation</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i>.</li>
</ul>

<p>Figure 83 illustrates a 'Clipping' geometric representation with use of <i>IfcBooleanClippingResult</i> between
an <i>IfcExtrudedAreaSolid</i> and an <i>IfcHalfSpaceSolid</i> to create a clipped body.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcColumn_Advanced-2-Layout1.png"" alt=""advanced column"" border=""0"" height=""292"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 83 &mdash; Column clipping</p></td></tr>
</table>

<p><i>AdvancedSweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedSweptSolid'</li>
</ul>
<p>The following additional constraints apply to the
'AdvancedSweptSolid' representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcSurfaceCurveSweptAreaSolid</i>,
<i>IfcFixedReferenceSweptAreaSolid</i>,
<i>IfcExtrudedAreaSolidTapered</i>,
<i>IfcRevolvedAreaSolidTapered</i> shall be supported.
<blockquote><small>NOTE View definitions and implementer
agreements can further constrain the allowed swept solid
types.</small></blockquote>
</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙not applicable</li>
</ul>
<p><i>MappedRepresentation Representation Type</i></p>
<p>The 'MappedRepresentation' representation type is supported as
it allows for reusing the geometry definition of the beam type at
all occurrences of the same type. The following attribute values
for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for the˙ 'SweptSolid',
'Clipping', 'AdvancedSweptSolid', 'SurfaceModel' and 'Bre'
geometric representation, shall apply to the
<i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
</EPM-HTML>"
1271;IfcColumnStandardCase;"<EPM-HTML>
<p>The standard column,
<i>IfcColumnStandardCase</i>, defines a column with certain
constraints for the provision of material usage, parameters and
with certain constraints for the geometric representation. The
<i>IfcColumnStandardCase</i> handles all cases of columns,
that:</p>
<ul>
<li>have a reference to the <i>IfcMaterialProfileSetUsage</i>
defining the material profile association of the column with the
cardinal point of its insertion relative to the local
placement.</li>
<li>are based on a sweep of a planar profile, or set of profiles,
as defined by the <i>IfcMaterialProfileSet</i></li>
<li>have an 'Axis' shape representation with constraints provided
below in the geometry use definition</li>
<li>have a 'Body' shape representation with constraints provided
below in the geometry use definition</li>
<li>have a start profile, or set of profiles, that is swept along
the directrix and might be changed uniformly by a taper
definition</li>
<li>are consistent in using the correct cardinal point offset of
the profile as compared to the 'Axis' and 'Body' shape
representation</li>
<li>are extruded perpendicular to the profile definition
plane</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE˙ View definitions and implementer
agreements may further constrain the applicable geometry types,
e.g. by excluding tapering from an <i>IfcBeamStandardCase</i>
implementation.</small></blockquote>
</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC2x4.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcColumn</i> defines the occuurence of any column, common
information about column types (or styles) is handled by
<i>IfcColumnType</i>. The <i>IfcColumnType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material layer set, common set of properties and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcColumnType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p>The <i>IfcColumnStandardCase</i> defines in addition that the
<i>IfcColumnType</i> should have a unique
<i>IfcMaterialProfileSet</i>, that is referenced by the
<i>IfcMaterialProfileSetUsage</i> assigned to all occurrences of
this column type.</p>

<p>Figure 84 illustrates assignment of <i>IfcMaterialProfileSetUsage</i> and <i>IfcMaterialProfileSet</i> to the <i>IfcColumnStandardCase</i> as the column occurrence and to the <i>IfcColumnType</i>. The same <i>IfcMaterialProfileSet</i> shall be shared by many occurrences of <i>IfcMaterialProfileSetUsage</i>. This relationship shall be consistent to the relationship between the <i>IfcColumnType</i> and the <i>IfcColumnStandardCase</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" >
<tr><td width=""510"" align=""left"" valign=""top"" rowspan=""2""><img alt=""Material profile set and usage"" src=""figures/IfcColumnStandardCase-01.png"" height=""500"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 84 &mdash; Column profile usage</p></td></tr>
</table>

<p>Figure 85 illustrates cardinal point alignment.</p>
<blockquote class=""note"">NOTE˙ It has to be guaranteed that the use of <i>IfcCardinalPointEnum</i> is consistent to the placement of the
extrusion body provided by <i>IfcExtrudedAreaSolid.Position</i></blockquote>
<blockquote class=""note"">NOTE˙ The cardinal points <b>7</b> (top left), and <b>6</b> (mid-depth right) are assigned according to the
definition at <i>IfcCardinalPointReference</i></blockquote>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top""><img alt=""Cardinal point usage"" src=""figures/IfcColumnStandardCase_CardinalPoint.png"" height=""250"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 85 &mdash; Column cardinal points</p></td></tr>
</table>

<p>Figure 86 illustrates assignment of a composite profile by using <i>IfcCompositeProfile</i> for geometric representation and several <i>IfcMaterialProfile</i>'s within the <i>IfcMaterialProfileSet</i>. The number of <i>IfcMaterialProfile</i>'s within the <i>IfcMaterialProfileSet</i> is restricted to maximal 2 and requires the use of <i>IfcExtrudedAreaSolidTapered</i>, or <i>IfcRevolvedAreaSolidTapered</i> for the correct 'Body' shape representation.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td><img alt=""Material profile set and usage"" src=""figures/IfcColumnStandardCase-02.png"" height=""550"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 86 &mdash; Column composite profiles</p></td></tr>
</table>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcColumnStandardCase</i> is defined by
<i>IfcMaterialProfileSetUsage</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Composite profile columns can be represented by refering to
several <i>IfcMaterialProfile</i>'s within the
<i>IfcMaterialProfileSet</i> that is referenced from the
<i>IfcMaterialProfileSetUsage</i>.</p>
<p>Material information can also be given at the
<i>IfcColumnType</i>, defining the common attribute data for all
occurrences of the same type. It is then accessible by the
inverse <i>IsDefinedBy</i> relationship pointing to
<i>IfcColumnType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i>. See <b>Type Use
Definition</b> for additional agreements for standard
columns.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcColumnStandardCase</i>
are defined at the supertype <i>IfcColumn</i>.</p>
<u><b>Quantity Use Definition</b></u>
<p>The quantities relating to the <i>IfcColumnStandardCase</i>
are defined at the supertype <i>IfcColumn</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcColumnStandardCase</i> are defined at the supertype
<i>IfcColumn</i>.</p>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcColumn</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcColumn</i>.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>The geometric representation of <i>IfcColumnStandardCase</i>
is defined using the following multiple shape representations for
its definition:</p>
<ul>
<li><u>Axis</u>: A three-dimensional open curve (subtype of
<i>IfcBoundedCurve</i>) defining the axis for the standard
column. The cardinal point is determined by the column axis.</li>
<li><u>Body</u>: A Swept Solid Representation or a CSG
representation defining the 3D shape of the standard column.</li>
</ul>
<blockquote><small>NOTE It is invalid to exchange a
'SurfaceModel', 'Brep', or 'MappedRepresentation' representation
for the 'Body' shape representation of an
<i>IfcColumnStandardCase</i>.</small></blockquote>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of
<i>IfcColumnStandardCase</i> is defined using the 'Axis'
representation. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve3D'</li>
</ul>
<p>The following additional constraints apply to the 'Axis'
representation, if the 'Body' shape representation has the
<i>RepresentationType</i> : 'SweptSolid':</p>
<ul>
<li><i>Axis</i> : <i>IfcPolyline</i> having two <i>Points</i>, or
<i>IfcTrimmedCurve</i> with <i>BasisCurve</i> of Type
<i>IfcLine</i>.</li>
<li>The axis curve lies on the z axis of the object coordinate
system</li>
</ul>

<p>As shown in Figure 87, the axis shall be defined along the z axis of
the object coordinate system. The axis representation can be used to
represent the system length of a column that may extent the body
length of the column.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""Axis"">
<tr><td align=""left"" valign=""top"" width=""300""><img src=
""figures/IfcColumnStandardCase_Axis-01.png"" alt=""Axis"" border=""1""></td></tr>
<tr><td><p class=""figure"">Figure 87 &mdash; Column axis representation</p></td></tr>
</table>

<p>As shown in Figure 88, the axis representation shall be used to represent the cardinal point as the offset between the 'Axis' and the extrusion path of the column. The extrusion path is provided as <i>IfcExtrudedAreaSolid.ExtrudedDirection</i> and should be parallel to the 'Axis'. It has to be guaranteed that the value provided by <i>IfcMaterialProfileSetUsage.CardinalPoint</i> is consistent to the <i>IfcExtrudedAreaSolid.Position</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""Axis"">
<tr><td align=""left"" valign=""top"" width=""300""><img src=""figures/IfcColumnStandardCase_Axis-02.png"" alt=""Axis"" border=""1""></td></tr>
<tr><td><p class=""figure"">Figure 88 &mdash; Column axis cardinal point</p></td></tr>
</table>

<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcColumnStandardCase</i> can be
represented using the representation types 'SweptSolid',
'Clipping', or 'AdvancedSweptSolid'.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i>,
<i>IfcRevolvedAreaSolid</i> shall be supported</li>
<li><u>Profile</u>: all subtypes of <i>IfcProfileDef</i> (with
exception of <i>IfcArbitraryOpenProfileDef</i>)</li>
<li><u>Profile Position</u> : For all single profiles, the
<i>IfcParameterizedProfileDef.Position</i> shall be NIL, or
having <i>Location</i> = 0.,0. and <i>RefDirection</i> =
1.,0.</li>
<li><u>Extrusion</u>:˙perpendicular to the profile direction. The
<i>IfcExtrudedAreaSolid.ExtrudedDirection</i> shall be
[0.,0.,1.].</li>
<li><u>Orientation</u>: The y-axis of the profile, as determined
by <i>IfcSweptAreaSolid.Position.P[2]</i> shall point to the
Y-Axis. It indicates the ""role"" of the column, a role=0&deg;
means y-axis of profile = Y-axis of reference coordinate
system.</li>
</ul>

<p>Figure 89 illustrates a standard geometric representation with cardinal point applied as <b>5</b> (mid-depth centre).</p>
<p>The following interpretation of dimension parameter applies for rectangular columns:</p>
<ul>
<li><i>IfcRectangleProfileDef.YDim</i> interpreted as column width</li>
<li><i>IfcRectangleProfileDef.XDim</i> interpreted as column depth</li>
</ul>
<p>The following interpretation of dimension parameter applies for circular columns:</p>
<ul>
<li><i>IfcCircleProfileDef.Radius</i> interpreted as column radius.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=""figures/IfcColumnStandardCase_SweptSolid-01.png"" alt=""standard column"" border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 89 &mdash; Column body extrusion</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' geometric representation</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Profile Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙see 'SweptSolid' geometric
representation</li>
<li><u>Orientation</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i> (or its subtypes).</li>
</ul>

<p>Figure 90 illustrates a 'Clipping' geometric representation with use of <i>IfcBooleanClippingResult</i> between
an <i>IfcExtrudedAreaSolid</i> and an <i>IfcHalfSpaceSolid</i> to create a clipped body, with cardinal point applied as <b>2</b> (bottom centre).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcColumnStandardCase_Clipping-01.png"" alt=""clipped column"" border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 90 &mdash; Column body clipping</p></td></tr>
</table>

<p><i>AdvancedSweptSolid Representation Type</i></p>
<p>The 'AdvancedSweptSolid' representation type is a valid body
representation of <i>IfcColumnStandardCase</i>. The following
attribute values for the <i>IfcShapeRepresentation</i> holding
this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedSweptSolid'</li>
</ul>
<p>The following additional constraints apply to the
'AdvancedSweptSolid' representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcSurfaceCurveSweptAreaSolid</i>,
<i>IfcFixedReferenceSweptAreaSolid</i>,
<i>IfcExtrudedAreaSolidTapered</i>,
<i>IfcRevolvedAreaSolidTapered</i> shall be supported.
<blockquote><small>NOTE View definitions and implementer
agreement can further constrain the allowed swept solid
types.</small></blockquote>
</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Profile Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙not applicable</li>
</ul>
</EPM-HTML>"
1277;IfcMember;"<EPM-HTML>
<p>An <i>IfcMember</i> is a
structural member designed to carry loads between or beyond
points of support. It is not required to be load bearing. The
orientation of the member (being horizontal, vertical or sloped)
is not relevant to its definition (in contrary to <i>IfcBeam</i>
and <i>IfcColumn</i>). An <i>IfcMember</i> represents a linear
structural element from an architectural or structural modeling
point of view and shall be used if it cannot be expressed more
specifically as either an <i>IfcBeam</i> or an
<i>IfcColumn</i>.</p>
<blockquote><small>NOTE The representation of a member in a
structural analysis model is provided by
<i>IfcStructuralCurveMember</i> being part of an
<i>IfcStructuralAnalysisModel</i>.</small></blockquote>
<p>The IFC specification provides two entities for member
occurrences:</p>
<ul>
<li><i>IfcMemberStandardCase</i> used for all occurrences of
members, that have a profile defined that is swept along a
directrix. The profile might be changed uniformly by a taper
definition along the directrix. The profile parameter and its
cardinal point of insertion can be fully described by the
<i>IfcMaterialProfileSetUsage</i>. These beams are always
represented geometricly by an 'Axis' and a 'SweptSolid' or
'AdvancedSweptSolid' shape representation (or by a 'Clipping'
geometry based on the swept solid), if a 3D geometric
representation is assigned. In addition they have to have a
corresponding <i>IfcMaterialProfileSetUsage</i> assigned.
<blockquote><small>NOTE˙ View definitions and implementer
agreements may further constrain the applicable geometry types,
e.g. by excluding tapering from an <i>IfcMemberStandardCase</i>
implementation.</small></blockquote>
</li>
<li><i>IfcMember</i> used for all other occurrences of members,
particularly for members with changing profile sizes along the
extrusion, or members defined by non-linear extrusion, or members
having only 'Brep', or 'SurfaceModel' geometry.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 2x2 Addendum.</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcMember</i> defines the occuurence of any member, common
information about member types (or styles) is handled by
<i>IfcMemberType</i>. The <i>IfcMemberType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material profile set, common set of properties and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcMemberType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcMemberType</i> is attached˙(i.e. if only
occurrence information is given) the <i>PredefinedType</i> should
be provided. If set to .USERDEFINED. a user defined value can be
provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcMember</i> is defined by the
<i>IfcMaterialProfileSet</i> or as fallback by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Material information can also be given at
the˙<i>IfcMemberType</i>, defining the common attribute data for
all occurrences of the same type.˙It is then accessible by the
inverse &lt;&lt;i&gt;<font color=""#0000FF"">IsTypedBy</font>
relationship pointing to <i>IfcMemberType.HasAssociations</i> and
via <i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterialProfileSet</i> or <i>IfcMaterial</i>. If both are
given, then the material directly assigned to <i>IfcMember</i>
overrides the material assigned to˙<i>IfcMemberType</i>.</p>
<p><u><b>Property Set Use Definition</b></u></p>
<p>The property sets relating to the <i>IfcMember</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcMember</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_MemberCommon.xml"" target=
""SOURCE"">Pset_MemberCommon</a>: common property set for all
member occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcMember</i> and
<i>IfcMemberStandardCase</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quanties shall
be never assigned to the <i>IfcMemberType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_MemberBaseQuantities.xml""
target=""SOURCE"">Qto_MemberBaseQuantities</a>: base quantities for
all member occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcMember</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcMember</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcMember</i> may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy, i.e.
<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcMember</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcMember</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to
a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the <font color=""#0000FF"">'Axis'</font>, 'Body',
and 'Box' representations are supported. The 'Box' representation
includes the representation type 'BoundingBox' and is explained
at <i>IfcBuildingElement</i>.</p>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcMember</i> is
defined using the 'Axis' representation. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', 'Curve3D'</li>
</ul>
<p>The axis representation can be used to represent the system
length of a member that may extent the body length of the
member.</p>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcBeam</i> can be represented
using the representation types 'SweptSolid', 'Clipping',
'AdvancedSweptSolid', 'MappedRepresentation', 'SurfaceModel', and
'Brep'. The representation types 'SurfaceModel' and 'Brep' are
explained at <i>IfcBuildingElement</i>.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i>,
<i>IfcRevolvedAreaSolid</i> shall be supported</li>
<li><u>Profile</u>: all subtypes of <i>IfcProfileDef</i> (with
exception of <i>IfcArbitraryOpenProfileDef</i>)˙</li>
<li><u>Extrusion</u>: All extrusion directions shall be
supported.</li>
</ul>

<p>Figure 99 illustrates a 'SweptSolid' geometric representation.  There are no restrictions or conventions on
how to use the local placement (black), solid of extrusion placement (red) and profile placement (green).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcMember_SweptSolid-01.png"" alt=""standard member"" border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 99 &mdash; Member swept solid</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' geometric representation</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙see 'SweptSolid' geometric
representation</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i> (or its subtypes).</li>
</ul>

<p>Figure 100 illustrates a 'Clipping' geometric representation with use of <i>IfcBooleanClippingResult</i> between an <i>IfcExtrudedAreaSolid</i> and an <i>IfcHalfSpaceSolid</i> to create a clipped body.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcMember_Clipping-01.png"" alt=""clipped member"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 100 &mdash; Member clipping</p></td></tr>
</table>

<p><i>AdvancedSweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedSweptSolid'</li>
</ul>
<p>The following additional constraints apply to the
'AdvancedSweptSolid' representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcSurfaceCurveSweptAreaSolid</i>,
<i>IfcFixedReferenceSweptAreaSolid</i>,
<i>IfcExtrudedAreaSolidTapered</i>,
<i>IfcRevolvedAreaSolidTapered</i> shall be supported.
<blockquote><small>NOTE View definitions and implementer
agreements can further constrain the allowed swept solid
types.</small></blockquote>
</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙not applicable</li>
</ul>
<p><i>MappedRepresentation Representation Type</i></p>
<p>The 'MappedRepresentation' representation type is supported as
it allows for reusing the geometry definition of the beam type at
all occurrences of the same type. The following attribute values
for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for the˙ 'SweptSolid',
'Clipping', 'AdvancedSweptSolid', 'SurfaceModel' and 'Bre'
geometric representation, shall apply to the
<i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
</EPM-HTML>"
1282;IfcMemberStandardCase;"<EPM-HTML>
<p>The standard member,
<i>IfcMemberStandardCase</i>, defines a member with certain
constraints for the provision of material usage, parameters and
with certain constraints for the geometric representation. The
<i>IfcMemberStandardCase</i> handles all cases of members,
that:</p>
<ul>
<li>have a reference to the <i>IfcMaterialProfileSetUsage</i>
defining the material profile association of the member with the
cardinal point of its insertion relative to the local
placement.</li>
<li>are based on a sweep of a planar profile, or set of profiles,
as defined by the <i>IfcMaterialProfileSet</i></li>
<li>have an 'Axis' shape representation with constraints provided
below in the geometry use definition</li>
<li>have a 'Body' shape representation with constraints provided
below in the geometry use definition</li>
<li>have a start profile, or set of profiles, that is swept along
the directrix and might be changed uniformly by a taper
definition</li>
<li>are consistent in using the correct cardinal point offset of
the profile as compared to the 'Axis' and 'Body' shape
representation</li>
<li>are extruded perpendicular to the profile definition
plane</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE˙ View definitions and implementer
agreements may further constrain the applicable geometry types,
e.g. by excluding tapering from an <i>IfcMemberStandardCase</i>
implementation.</small></blockquote>
</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC2x4.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcMember</i> defines the occuurence of any member, common
information about member types (or styles) is handled by
<i>IfcMemberType</i>. The <i>IfcMemberType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material layer set, common set of properties and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcMemberType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p>The <i>IfcMemberStandardCase</i> defines in addition that the
<i>IfcMemberType</i> should have a unique
<i>IfcMaterialProfileSet</i>, that is referenced by the
<i>IfcMaterialProfileSetUsage</i> assigned to all occurrences of
this beam type.</p>

<p>Figure 101 illustrates assignment of <i>IfcMaterialProfileSetUsage</i> and <i>IfcMaterialProfileSet</i> to the <i>IfcMemberStandardCase</i> as the member occurrence and to the <i>IfcMemberType</i>. The same <i>IfcMaterialProfileSet</i> shall be shared by many occurrences of <i>IfcMaterialProfileSetUsage</i>. This relationship shall be consistent to the relationship between the <i>IfcMemberType</i> and the <i>IfcMemberStandardCase</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td width=""510"" align=""left"" valign=""top""><img alt=""Material profile set and usage"" src=""figures/IfcMemberStandardCase-01.png"" height=""500"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 101 &mdash; Member profile usage</p></td></tr>
</table>


<p>Figure 102 illustrates assignment of a composite profile by using <i>IfcCompositeProfile</i> for geometric representation and several <i>IfcMaterialProfile</i>'s within the <i>IfcMaterialProfileSet</i>. The number of <i>IfcMaterialProfile</i>'s within the <i>IfcMaterialProfileSet</i> is restricted to maximal 2 and
requires the use of <i>IfcExtrudedAreaSolidTapered</i>, or <i>IfcRevolvedAreaSolidTapered</i> for the correct 'Body' shape representation.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td width=""510"" align=""left"" valign=""top""><img alt=""Material profile set and usage"" src=
""figures/IfcMemberStandardCase-02.png"" height=""550"" width=""500""></td></tr>
<tr><td><p class=""figure"">Figure 102 &mdash; Member composite profiles</p></td></tr>
</table>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcMemberStandardCase</i> is defined by
<i>IfcMaterialProfileSetUsage</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Composite profile members can be represented by refering to
several <i>IfcMaterialProfile</i>'s within the
<i>IfcMaterialProfileSet</i> that is referenced from the
<i>IfcMaterialProfileSetUsage</i>.</p>
<p>Material information can also be given at the
<i>IfcMemberType</i>, defining the common attribute data for all
occurrences of the same type. It is then accessible by the
inverse <i>IsDefinedBy</i> relationship pointing to
<i>IfcMemberType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i>. See <b>Type Use
Definition</b> for additional agreements for standard
members.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcMemberStandardCase</i>
are defined at the supertype <i>IfcMember</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcMemberStandardCase</i>
are defined at the supertype <i>IfcMember</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcMemberStandardCase</i> are defined at the supertype
<i>IfcMember</i>.</p>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcMemberStandardCase</i>
is given by the <i>IfcProductDefinitionShape</i>, allowing
multiple geometric representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcMember</i>.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>The geometric representation of <i>IfcMemberStandardCase</i>
is defined using the following multiple shape representations for
its definition:</p>
<ul>
<li><u>Axis</u>: A two- or three dimensional open curve
(<i>IfcBoundedCurve</i>) defining the axis for the standard
member. The cardinal point is determined by the member axis.</li>
<li><u>Body</u>: A Swept Solid Representation or a CSG
representation defining the 3D shape of the standard member.</li>
</ul>
<blockquote><small>NOTE It is invalid to exchange a
'SurfaceModel', 'Brep', or 'MappedRepresentation' representation
for the 'Body' shape representation of an
<i>IfcMemberStandardCase</i>.</small></blockquote>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of
<i>IfcMemberStandardCase</i> is defined using the 'Axis'
representation. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', or 'Curve3D'</li>
</ul>
<p>The following additional constraints apply to the 'Axis'
representation:</p>
<ul>
<li><i>Axis</i> : <i>IfcPolyline</i> having two <i>Points</i>, or
<i>IfcTrimmedCurve</i> with <i>BasisCurve</i> of Type
<i>IfcLine</i>.</li>
</ul>


<p>As shown in Figure 103, the axis representation can be used to represent the system length of a member that may extent the body length of the member.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""Axis"">
<tr><td align=""left"" valign=""top"" width=""350""><img src=""figures/IfcMemberStandardCase_Axis-01.png"" alt=""Axis"" border=""1""></td></tr>
<tr><td><p class=""figure"">Figure 103 &mdash; Member axis representation</p></td></tr>
</table>

<p>As shown in Figure 104, the axis representation shall be used to represent the cardinal point as the offset between the 'Axis' and the extrusion path of the member. The extrusion path is provided as <i>IfcExtrudedAreaSolid.ExtrudedDirection</i> and should be parallel to the 'Axis'.  It has to be guaranteed that the value provided by <i>IfcMaterialProfileSetUsage.CardinalPoint</i> is consistent to the <i>IfcExtrudedAreaSolid.Position</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""Axis"">
<tr><td align=""left"" valign=""top"" width=""350""><img src=""figures/IfcMemberStandardCase_Axis-02.png"" alt=""Axis"" border=""1""></td><td align=""left"" valign=""top""></td></tr>
<tr><td><p class=""figure"">Figure 104 &mdash; Member axis cardinal point</p></td></tr>
</table>


<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcMemberStandardCase</i> can be
represented using the representation types 'SweptSolid',
'Clipping', or 'AdvancedSweptSolid'.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The standard geometric representation of
<i>IfcMemberStandardCase</i> is defined using the 'SweptSolid'
representation. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i>,
<i>IfcRevolvedAreaSolid</i> shall be supported</li>
<li><u>Profile</u>: all subtypes of <i>IfcProfileDef</i> (with
exception of <i>IfcArbitraryOpenProfileDef</i>)</li>
<li><u>Profile Position</u> : For all single profiles, the
<i>IfcParameterizedProfileDef.Position</i> shall be NIL, or
having <i>Location</i> = 0.,0. and <i>RefDirection</i> =
1.,0.</li>
<li><u>Extrusion</u>:˙perpendicular to the profile
direction.</li>
<li><u>Orientation</u>: The y-axis of the profile, as determined
by <i>IfcSweptAreaSolid.Position.P[2]</i> shall point to the
Z-Axis. It indicates the ""role"" of the column, a role=0&deg;
means y-axis of profile = Z-axis of reference coordinate system.
In the exception of a vertical member, the y-axis shall point to
the Y-axis.</li>
</ul>

<p>Figure 105 illustrates a 'SweptSolid' geometric representation with cardinal point applied as <b>1</b> (bottom left).</p>
<p>The following interpretation of dimension parameter applies for rectangular members:</p>
<ul>
<li><small><i>IfcRectangleProfileDef.YDim</i> interpreted as member width</small></li>
<li><small><i>IfcRectangleProfileDef.XDim</i> interpreted as member depth</small></li>
</ul>
<p>The following interpretation of dimension parameter applies for circular members:</p>
<ul>
<li><small><i>IfcCircleProfileDef.Radius</i> interpreted as beam radius.</small></li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBeamStandardCase_SweptSolid-01.png"" alt=
""standard member"" border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 105 &mdash; Member body extrusion</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The advanced geometric representation of
<i>IfcMemberStandardCase</i> is defined using the 'Clipping'
geometry. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' geometric representation</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Profile Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙see 'SweptSolid' geometric
representation</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i> (or its subtypes).</li>
</ul>

<p>Figure 106 illustrates an advanced geometric representation with use of <i>IfcBooleanClippingResult</i> between
an <i>IfcExtrudedAreaSolid</i> and an <i>IfcHalfSpaceSolid</i> to create a clipped body, with cardinal point applied as <b>4</b> (mid-depth left).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcBeamStandardCase_Clipping-01.png"" alt=""clipped beam"" border=""1"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 06 &mdash; Member body clipping</p></td></tr>
</table>

<p><i>AdvancedSweptSolid Representation Type</i></p>
<p>The 'AdvancedSweptSolid' representation type is a valid body
representation of <i>IfcMemberStandardCase</i>. The following
attribute values for the <i>IfcShapeRepresentation</i> holding
this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedSweptSolid'</li>
</ul>
<p>The following additional constraints apply to the
'AdvancedSweptSolid' representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcSurfaceCurveSweptAreaSolid</i>,
<i>IfcFixedReferenceSweptAreaSolid</i>,
<i>IfcExtrudedAreaSolidTapered</i>,
<i>IfcRevolvedAreaSolidTapered</i> shall be supported.
<blockquote><small>NOTE View definitions and implementer
agreement can further constrain the allowed swept solid
types.</small></blockquote>
<blockquote><small>NOTE Using <i>IfcExtrudedAreaSolidTapered</i>,
or <i>IfcRevolvedAreaSolidTapered</i> requires the use of two
<i>IfcMaterialProfile</i>'s within the
<i>IfcMaterialProfileSet</i> assinged to the
<i>IfcBeamStandardCase</i></small></blockquote>
</li>
<li><u>Profile</u>: see 'SweptSolid' geometric
representation</li>
<li><u>Profile Position</u> : see 'SweptSolid' geometric
representation</li>
<li><u>Extrusion</u>:˙not applicable</li>
</ul>
</EPM-HTML>"
1299;IfcWall;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Vertical construction
usually in masonry or in concrete which bounds or subdivides a
construction works and fulfils a load bearing or retaining
function.</p>
<p><u>Definition from IAI</u>: The wall represents a vertical
construction that bounds or subdivides spaces. Wall are usually
vertical, or nearly vertical, planar elements, often designed to
bear structural loads. A wall is however˙not required to be load
bearing.</p>
<blockquote><small>NOTE NOTE There is a representation of walls
for structural analysis provided by a proper subtype of
<i>IfcStructuralMember</i> being part of the
<i>IfcStructuralAnalysisModel</i>.</small><br>
<br>
<small>NOTE An arbitrary planar element to which this semantic
information is not applicable, e.g. is not predominantly
vertical, shall be modeled as
<i>IfcPlate</i></small></blockquote>
<p>A wall may have openings, such as wall openings, openings used
for windows or doors, or niches and recesses. They are defined by
an <i>IfcOpeningElement</i> attached to the wall using the
inverse relationship <i>HasOpenings</i> pointing to
<i>IfcRelVoidsElement</i>.</p>
<p>The IFC specification provides two entities for wall
occurrences:</p>
<ul>
<li><i>IfcWallStandardCase</i> ˙used for all occurrences of
walls, that have a non-changing thickness along the wall path and
where the thickness parameter can be fully described by a
material layer set. These walls are always represented
geometrically by an 'Axis' and a 'SweptSolid' shape
representation (or by a 'Clipping' geometry based on
'SweptSolid'), if a 3D geometric representation is assigned. In
addition they have to have a corresponding
<i>IfcMaterialProfileSetUsage</i> assigned.</li>
<li><i>IfcWallElementedCase</i> used for occurrences of walls
which are aggregated from subordinate elements, following
specific decomposition rules expressed by the mandatory use of
<i>IfcRelAggregates</i> relationship.</li>
<li><i>IfcWall</i> ˙used for all other occurrences of wall,
particularly for walls with changing thickness along the wall
path (e.g. polygonal walls), or walls with a non-rectangular
cross sections (e.g. L-shaped retaining walls), and walls having
an extrusion axis that is unequal to the global Z axis of the
project (i.e. non-vertical walls), or walls having only 'Brep',
or 'SurfaceModel' geometry.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC Release 1.0</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcWall</i> defines the occurrence of any wall, common
information about˙wall types (or styles) is handled by
<i>IfcWallType</i>. The <i>IfcWallType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material layer set, common set of properties and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcWallType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcWallType</i> is attached˙(i.e. if only occurrence
information is given) the <i>PredefinedType</i> should be
provided. If set to .USERDEFINED. a user defined value can be
provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcWall</i> is defined by
<i>IfcMaterialLayerSet</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Multi-layer walls can be represented by referring to several
<i>IfcMaterialLayer</i>'s within the
<i>IfcMaterialLayerSet</i>.˙</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterialLayerSetUsage</i> to an <i>IfcWall</i>. Only the
subtype <i>IfcWallStandardCase</i> supports this
concept.</small></blockquote>
<p>Material information can also be given at the
<i>IfcWallType</i>, defining the common attribute data for all
occurrences of the same type.˙It is then in addition accessible
by the inverse <i><font color=""#0000FF"">IsTypedBy</font></i>
relationship pointing to <i>IfcWallType.HasAssociations</i> and
via <i>IfcRelAssociatesMaterial.RelatingMaterial</i>.</p>
<p><u><b>Property Set Use Definition</b></u></p>
<p>The property sets relating to the <i>IfcWall</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcWall</i> are part
of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_WallCommon.xml""
target=""SOURCE"">Pset_WallCommon</a>: common property set for all
wall occurrences</li>
</ul>
<p>Property sets can also be given at the <i>IfcWallType</i>,
defining the common property data for all occurrences of the same
type.˙It is then accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcWallType.HasPropertySets</i>. If both are given, then the
properties directly assigned to <i>IfcWall</i> overrides the
properties assigned to <i>IfcWallType</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcWall</i> and
<i>IfcWallStandardCase</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quantities shall
never be assigned to the <i>IfcWallType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_WallBaseQuantities.xml""
target=""SOURCE"">Qto_WallBaseQuantities</a>: base quantities for
all wall occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcWall</i> (and the subtype
<i>IfcWallStandardCase</i>) as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierarchical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcWall</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The˙<i>IfcWall</i> may be aggregated into an element assembly
using the objectified relationship <i>IfcRelAggregates</i>,
referring to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype.<br>
In this case the wall should not be additionally contained in the
project spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p>The˙<i>IfcWall˙</i>may also be an aggregate i.e. being
composed by other elements and acting as an assembly using the
objectified relationship <i>IfcRelAggregates</i>, referring to it
by its inverse attribute
<i>SELF\IfcObjectDefinition.IsDecomposedBy</i>. Components of a
wall are described by instances of <i>IfcBuildingElementPart</i>
that are aggregated to form a complex wall.<br>
In this case, the contained˙<i>IfcBuildingElementPart</i>'s
should not be additionally contained in the project spatial
hierarchy, i.e. the inverse attribute
<i>SELF\IfcElement.ContainedInStructure</i> of
<i>IfcBuildingElementPart</i> should be <i>NIL.</i></p>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcWall</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representation. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcWall</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the 'Axis', <font color=""#0000FF"">'Surface'</font>,
<font color=""#0000FF"">'FootPrint'</font>, 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcWall</i> is defined
using the 'Axis' representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D'</li>
</ul>
<blockquote><small>NOTE The 'Axis' is not used to locate the
material layer set, only the subtype <i>IfcWallStandardCase</i>
provides this capability.</small></blockquote>
<p><b>Surface Representation</b></p>
<p>The surfacic geometric representation of <i>IfcWall</i> is
defined using the 'Surface' representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface3D'</li>
</ul>
<blockquote><small>NOTE The 'Surface' can be used to define a
surfacic model of the building (e.g. for analytical purposes, or
for reduced Level of Detail representation).</small></blockquote>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcWall</i> can be represented
using the representation types 'SweptSolid', 'Clipping',
'SurfaceModel', and 'Brep'. The representation types
'SurfaceModel' and 'Brep' are explained at
<i>IfcBuildingElement</i>.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<blockquote><small>If the wall body can be described by a
vertical extrusion of a polygonal footprint with constant
thickness along the axis (where vertical = into the direction of
the global Z axis), the subtype <i>IfcWallStandardCase</i> should
be used. If the extrusion is not equal to global Z, then the
<i>IfcWall</i> should be used.</small></blockquote>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef</i> is
required.</li>
<li><u>Extrusion</u>:˙All extrusion directions shall be
supported.</li>
</ul>
<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The same additional constraints apply as defined for the
'SweptSolid' representation.</p>
<p><b><u>Connection Geometry</u></b></p>
<p>The connection between two walls is represented by the
<i>IfcRelConnectsPathElements</i>. The use of the parameter of
that relationship object is defined at the level of the subtypes
of <i>IfcWall</i> and at the
<i>IfcRelConnectsPathElements</i>.</p>
</EPM-HTML>"
1305;IfcWallStandardCase;"<EPM-HTML>
<p>The <em>IfcWallStandardCase</em> defines a wall with certain
constraints for the provision of parameters and with certain
constraints for the geometric representation. The
<em>IfcWallStandardCase</em> handles all cases of walls, that are
extruded vertically:</p>
<ul>
<li>along the positive z axis of the wall object coordinate system,
and</li>
<li>along the positve z axis of the global (world) coordinate
system</li>
</ul>
<p>and have a single thickness along the path for each wall layer,
i.e.:</p>
<ul>
<li>parallel sides for straight walls</li>
<li>co-centric sides for curved walls.</li>
</ul>
<p>and have either:</p>
<ul>
<li>a straight line axis (straight wall), or</li>
<li>a circular arc axis (round wall).</li>
</ul>
<p>and shall not have</p>
<ul>
<li>aggregated components, that is, parts aggregated to a wall by <i>IfcRelAggregates</i></li>
<li>shape representation for 'Body' not being an extrusion, or clipped extrusion</li>
</ul>
<p>The following parameter have to be provided:</p>
<ul>
<li>Wall height, taken from the depth of extrusion, provided by the geometric representation.</li>
<li>Wall thickness, taken from the material layer set usage, attached to the wall</li>
<li>Wall offset from axis, taken from the material layer set usage, attached to the wall</li>
</ul>
<p>The <em>IfcWallStandardCase</em> requires the provision of the
wall axis either a straight line that is parallel to the x-axis of
the object coordinate system, or a circular arc where the tangent
at start is parallel to the x-axis of the object coordinate system.
The direction of the wall axis shall be the positive direction of
that x-axis.</p>
<p>The material of the wall is defined by the
<em>IfcMaterialLayerSetUsage</em> and is attached by the
<em>IfcRelAssociatesMaterial</em> objectified relationship. It is
accessible by the inverse <em>HasAssociations</em> relationship.
The material layer set usage has to be given (enforced by where
rule).</p>
<blockquote class=""history"">HISTORY New entity in IFC Release 2x.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p>The type information relating to the
<em>IfcWallStandardCase</em> is defined at the supertype
<em>IfcWall</em>. As an additional use agreement for standard
walls, the <em>IfcWallType</em> should have a unique
<em>IfcMaterialLayerSet</em>, that is referenced by
the&nbsp;<em>IfcMaterialLayerSetUsage</em> assigned to all
occurrences of this <em>IfcWallType</em>.</p>

<p>Figure 134 illustrates assignment of <em>IfcMaterialLayerSetUsage</em> and <em>IfcMaterialLayerSet</em> to the wall type and the wall occurrence.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top""><img alt=""Material layer set and usage"" src=""figures/IfcWallStandardCase_MaterialUsage-01.png"" height=""220"" width=""501""></td></tr>
<tr><td><p class=""figure"">Figure 134</p></td></tr>
</table>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <em>IfcWallStandardCase</em> is defined by
<em>IfcMaterialLayerSetUsage</em> and attached by the
<em>IfcRelAssociatesMaterial</em><em>.RelatingMaterial</em>. It is
accessible by the inverse <em>HasAssociations</em> relationship.
Multi-layer walls can be represented by refering to several
<em>IfcMaterialLayer</em>'s within the <em>IfcMaterialLayerSet</em>
that is referenced from the
<em>IfcMaterialLayerSetUsage</em>.&nbsp;</p>
<p>Material information can also be given at the
<em>IfcWallType</em>, defining the common attribute data for all
occurrences of the same type.&nbsp;It is then accessible by the
inverse <em>IsDefinedBy</em> relationship pointing to
<em>IfcSlabType.HasAssociations</em> and via
<em>IfcRelAssociatesMaterial.RelatingMaterial</em>. See <b>Type Use
Definition</b> for additional agreements for standard slabs.</p>

<p>Figure 134 illustrates material layer usage, where the following conventions shall be met:</p>
<ul>
<li>The reference coordinate system is the local coordinate system established by the <em>ObjectPlacement</em> of the <em>IfcWallStandardCase</em>.</li>
<li>The reference axis is the axis defined by the <em>IfcShapeRepresentation</em> with <em>RepresentationType</em>='Axis' as one of the
<em>Representation.Representations</em> of the <em>IfcWallStandardCase</em>.</li>
<li>The <em>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</em> is given as a distance from this axis.</li>
<li>The <em>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</em> is the distance parallel to the reference axis and always within the base
(XY) plane of the reference coordinate system. A positve value of <em>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</em> would
then point into the positive y-axis of the reference coordinate system.</li>
<li>The <em>IfcMaterialLayerSetUsage.DirectionSense</em> defines how the <em>IfcMaterialLayer</em>'s are assigned to the reference axis. POSITIVE means in direction to the positive y-axis of the reference coordinate system.</li>
<li>The <em>Thickness</em> of each <em>IfcMaterialLayer</em> is provided starting from the <em>OffsetFromReferenceLine</em> and in the direction given by <em>DirectionSense</em>. It is applied without any gap or overlap between two consecutive layers. The <em>TotalThickness</em> of the <em>IfcMaterialLayerSet</em> is the sum of all layer thicknesses.</li>
<li>The <em>IfcMaterialLayerSetUsage.LayerSetDirection</em> is always AXIS2.</li>
</ul>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""material use definition for wall slabs"">
<tr><td align=""left"" valign=""top"" width=""610""><img src=""figures/IfcMaterialLayerSetUsage_Wall-01.png"" alt=""roof slab material layer set"" width=""601"" height=""351"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 134 &mdash; Wall material layers</p></td></tr>
</table>

<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <em>IfcWallStandardCase</em>
are defined at the supertype <em>IfcWall</em>.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <em>IfcWallStandardCase</em> are
defined at the supertype <em>IfcWall</em>.</p>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <em>IfcWallStandardCase</em> is
given by the <em>IfcProductDefinitionShape</em>, allowing multiple
geometric representation. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement defining the wall object coordinate
system is defined at the supertype <em>IfcWall</em>.</p>
<p><b><em>Geometric Representation</em></b></p>
<p>The standard geometric representation of
<em>IfcWallStandardCase</em> is defined using the following
multiple shape representations for its definition:</p>
<ul>
<li><u>Axis</u>: A two-dimensional open curve
(<em>IfcBoundedCurve</em>) defining the axis for the standard wall.
The material layer offset is measured from the wall axis.</li>
<li><u>Body</u>: A Swept Solid Representation or a CSG
representation defining the 3D shape of the standard wall</li>
</ul>
<blockquote><small>NOTE&nbsp; It is invalid to exhange a
'SurfaceModel', or 'Brep' or 'MappedRepresentation' representation
for the 'Body' shape representation of an
<em>IfcWallStandardCase</em>.</small></blockquote>
<p><b>Axis Representation</b></p>
<p>The wall axis is represented by a two-dimensional open curve
within a particular shape representation. The wall axis is used to
apply the material layer set usage parameter to the wall geometry.
The following attribute values shall be used</p>
<ul>
<li>RepresentationIdentifier : 'Axis'</li>
<li>RepresentationType : 'Curve2D'</li>
</ul>


<p>Figure 135 illustrates an axis representation for a straight wall. In case of a straight wall, the set of items shall
include a single geometric representation item of type <em>IfcPolyline</em> or <em>IfcTrimmedCurve</em> with the <em>BasisCurve</em> being an <em>IfcLine</em>. The <em>IfcPolyline</em> or <em>IfcTrimmedCurve</em> shall be parallel (here in a special case co-linear) to the x-axis
of the object coordinate system. The direction shall be identical to the direction of the x-axis.</p>

<p>Figure 136 illustrates an axis representation for a curved wall. In case of a curved wall, the set of items shall include
a single geometric representation item of type <em>IfcTrimmedCurve</em>. The curve shall have a <em>BasisCurve</em> of type <em>IfcCircle</em>. The tangent of the <em>IfcTrimmedCurve</em> shall be parallel at start to the x-axis of the object coordinate system. The direction shall be identical to the direction of the x-axis.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr>
<td align=""left"" valign=""top""><img src=""figures/IfcWallStandard_StraigthWall_01-Layout1.gif"" alt=""straight wall axis"" border=""0"" height=""299"" width=""393""></td>
<td align=""left"" valign=""top""><img src=""figures/IfcWallStandard_CurvedWall_01-Layout1.gif"" alt=""curved wall axis"" border=""0"" height=""299"" width=""393""></td>
</tr>
<tr>
<td width=""393""><p class=""figure"">Figure 135 &mdash; Wall axis straight</p></td>
<td width=""393""><p class=""figure"">Figure 136 &mdash; Wall axis curved</p></td>
</tr>
</table>

<p><b>Body Representation</b></p>
<p>The body representation of <em>IfcWallStandardCase</em> is
defined by using 'SweptSolid' representation for walls without
clippings or 'Clipping' representation for walls with clippings
(e.g. under sloped roof slabs).</p>
<p><em>SweptSolid Representation Type</em></p>
<p>The following attribute values for the
<em>IfcShapeRepresentation</em> holding this geometric
representation shall be used:</p>
<ul>
<li>RepresentationIdentifier : 'Body'</li>
<li>RepresentationType : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation:</p>
<ul>
<li><u>Solid</u>: <em>IfcExtrudedAreaSolid</em> is required,</li>
<li><u>Profile</u>: <em>IfcArbitraryClosedProfileDef</em> and
<em>IfcRectangleProfileDef</em> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded vertically,
i.e., in the direction of the z-axis of the co-ordinate system of
the referred spatial structure element. It might be further
constraint to be in the direction of the global z-axis in
implementers agreements. The extrusion axis shall be perpendicular
to the swept profile, i.e. pointing into the direction of the
z-axis of the Position of the <em>IfcExtrudedAreaSolid</em>.</li>
</ul>

<p>The profile of a wall is described in the ground view and extruded vertically. The profile (also identical with the foot print of the wall) is defined by the <em>IfcArbitraryClosedProfileDef</em> (excluding its subtypes). The profile is given with all wall connections already resolved.</p>

<p>Figure 137 illustrates a body representation for a straight wall. In case of a straight wall, the two sides of the profile shall be parallel to the wall axis, that is, the wall has a single unchanged thickness.</p>

<p>Figure 138 illustrates a body representation for a curved wall. In case of a curved wall, the two sides of the profile shall be parallel (with defined offset) to the wall axis, that is, the wall has a single unchanged thickness.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr>
<td align=""left"" valign=""top""><img src=""figures/IfcWallStandard_StraigthWall_02-Layout1.gif"" alt=""straight wall body"" border=""0"" height=""299"" width=""393""></td>
<td align=""left"" valign=""top""><img src=""figures/IfcWallStandard_CurvedWall_02-Layout1.gif"" alt=""curved wall body"" border=""0"" height=""299"" width=""393""></td>
</tr>
<tr>
<td width=""393""><p class=""figure"">Figure 137 &mdash; Wall body extrusion straight</p></td>
<td width=""393""><p class=""figure"">Figure 138 &mdash; Wall body extrusion curved</p></td>
</tr>
</table>

<p><em>Clipping Representation Type</em></p>
<p>The following attribute values for the
<em>IfcShapeRepresentation</em> holding this geometric
representation shall be used:</p>
<ul>
<li><em>RepresentationIdentifier</em> : 'Body'</li>
<li><em>RepresentationType</em> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the 'Clipping'
representation:</p>
<ul>
<li><u>Solid</u>: see standard geometric representation</li>
<li><u>Profile</u>: see standard geometric representation</li>
<li><u>Extrusion</u>: see standard geometric representation</li>
<li><u>Boolean result</u>: The <em>IfcBooleanClippingResult</em>
shall be supported, allowing for Boolean differences between the
swept solid (here <em>IfcExtrudedAreaSolid</em>) and one or several
<em>IfcHalfSpaceSolid</em> (or subtypes).</li>
</ul>

<p>Figure 139 illustrates a clipping for a straight wall using an <em>IfcPolygonalBoundedHalfSpace</em> as <em>SecondOperand</em> in
the <em>IfcBooleanClippingResult</em>.</p>

<p>Figure 140 illustrates a clipping for a curved wall using an <em>IfcHalfSpaceSolid</em> as <em>SecondOperand</em> in the
<em>IfcBooleanClippingResult</em>.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr>
<td><img src=""figures/IfcWallStandard_StraigthWall_03-Layout1.gif"" alt=""straight wall clipping"" border=""0"" height=""299"" width=""397""></td>
<td><img src=""figures/IfcWallStandard_CurvedWall_03-Layout1.gif"" alt=""curved wall clipping"" border=""0"" height=""300"" width=""400""></td>
</tr>
<tr>
<td width=""397""><p class=""figure"">Figure 139 &mdash; Wall body clipping straight</p></td>
<td width=""400""><p class=""figure"">Figure 140 &mdash; Wall body clipping curved</p></td>
</tr>
</table>

</EPM-HTML>"
1307;IfcWallElementedCase;"<EPM-HTML>
<p>The <i>IfcWallElementedCase</i>
defines a wall with certain constraints for the provision of its
components. The <i>IfcWallElementedCase</i> handles all cases of
walls, that are decomposed into parts:˙</p>
<ul>
<li>having components being assigned to the
<i>IfcWallElementedCase</i> using the <i>IfcRelAggregates</i>
relationship accessible by the inverse relationship
<i>IsDecomposedBy</i>.</li>
<li>applying the constraint that the parts within the
decomposition shall be of type <i>IfcMember</i>, <i>IfcPlate</i>,
<i>IfcBuildingElementPart</i> or
<i>IfcBuildingElementProxy</i>.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4.</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcWallElementedCase</i>
are defined at the supertype <i>IfcWall</i>.</p>
<blockquote><small>NOTE The parts within the decomposition
relationship may define their own property
sets.</small></blockquote>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcWallElementedCase</i> are
defined at the supertype <i>IfcWall</i>.</p>
<blockquote><small>NOTE The parts within the decomposition
relationship may define their own individual
quantities.</small></blockquote>

<p><u><b>Voiding Use Definition</b></u>:</p>

<p>As shown in Figure 132, openings within the composite wall are directly assigned to <i>IfcWallElementedCase</i> using <i>IfcRelVoidsElement</i> pointing to <i>IfcOpeningElement</i> and apply to all aggregated parts. If individual parts have cutting and other voiding features, then the decomposed parts have a separate voiding relationship <i>IfcRelVoidsElement</i> pointing to <i>IfcVoidingFeature</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""voiding"">
<tr><td valign=""top""><img src=""figures/IfcWallElementedCase_fig01.png"" alt=""voiding"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 132 &mdash; Wall elemented voiding</p></td></tr>
</table>

<p><u><b>Decomposition Use Definition</b></u>:</p>
<p>The following guidance is provided for the components of the
<i>IfcWallElementedCase</i>. The following component entity types
should be used:</p>
<ul style=""list-style-type:none"">
<li>Framed Walls
<ul style=""list-style-type:square"">
<li>studs : <i>IfcMember</i></li>
<li>plates : <i>IfcMember</i></li>
<li>drywall : <i>IfcPlate</i></li>
<li>wood sheathing : <i>IfcPlate</i></li>
<li>insulation : <i>IfcBuildingElementPart</i></li>
<li>precast panel : <i>IfcBuildingElementPart</i></li>
<li>others : <i>IfcBuildingElementPart</i></li>
</ul>
</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcWallElementedCase</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcWall</i>. The local placement of the
<i>IfcWallElementedCase</i> defines the parent coordinate systems
for the parts within the decomposition. All parts shall be
positioned relative to the <i>IfcWallElementedCase</i>.</p>
<p><b><i>Geometric Representation</i></b></p>
<p>The standard geometric representation of
<i>IfcWallElementedCase</i> is defined using the following
multiple shape representations for its definition:</p>
<ul>
<li><u>Axis</u>: A two-dimensional open curve being a subtype of
<i>IfcBoundedCurve</i> defining the axis for the elemented wall.
It maybe used as a simplified representation directly at the
elemented wall.</li>
<li><u>Surface</u>: A three-dimensional surface being a subtype
of <i>IfcBoundedSurface</i> defining the reference surface for
the elemented wall. It maybe used as a simplified representation
directly at the elemented wall.</li>
</ul>
<blockquote><small>NOTE˙ It is invalid to exhange a 'Body' shape
representation of an <i>IfcWallElementedCase</i>. The body
geometry is defined by the parts within the
decomposition.</small></blockquote>
<p><b>Axis Representation</b></p>
<p>The wall axis is represented by a two-dimensional open curve
within a particular shape representation.</p>
<ul>
<li>RepresentationIdentifier : 'Axis'</li>
<li>RepresentationType : 'Curve2D'</li>
</ul>
<p><b>Surface Representation</b></p>
<p>The surfacic geometric representation of
<i>IfcWallElementedCase</i> is defined using the 'Surface'
representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface3D'</li>
</ul>
<blockquote><small>NOTE The 'Surface' can be used to define a
surfacic model of the building (e.g. for analytical purposes, or
for reduced Level of Detail representation). It could suppress
the geometric details of the parts in the
decomposition.</small></blockquote>
</EPM-HTML>"
1318;IfcSlab;"<EPM-HTML> 
<p>A slab is a component of the
construction that normally encloses a space vertically. The slab
may provide the lower support (floor) or upper construction (roof
slab) in any space in a building. It shall be noted, that only
the core or constructional part of this construction is
considered to be a slap. The upper finish (flooring, roofing) and
the lower finish (ceiling, suspended ceiling) are considered to
be coverings. A special type of slab is the landing, described as
a floor section to which one or more stair flights or ramp
flights connect.</p>
<blockquote><small>NOTE There is a representation of slabs for
structural analysis provided by a proper subtype of
<i>IfcStructuralMember</i> being part of the
<i>IfcStructuralAnalysisModel</i>.</small><br>
<br>
<small>NOTE ˙An arbitrary planar element to which this semantic
information is not applicable or irrelevant shall be modeled as
<i>IfcPlate</i>.</small></blockquote>
<p>A slab may have openings, such as floor openings, or recesses.
They are defined by an <i>IfcOpeningElement</i> attached to the
slab using the inverse relationship <i>HasOpenings</i> pointing
to <i>IfcRelVoidsElement</i>.</p>
<p>The IFC specification provides three entities for slab
occurrences:</p>
<ul>
<li><i>IfcSlabStandardCase</i> used for all occurrences of slabs,
that are prismatic and where the thickness parameter can be fully
described by the <i>IfcMaterialLayerSetUsage</i>. These slabs are
always represented geometrically by a 'SweptSolid' geometry (or
by a 'Clipping' geometry based on 'SweptSolid'), if a 3D
geometric representation is assigned. In addition they have to
have a corresponding <i>IfcMaterialLayerSetUsage</i>
assigned.</li>
<li><i>IfcSlabElementedCase</i> used for occurrences of slabs
which are aggregated from subordinate elements, following
specific decomposition rules expressed by the mandatory use of
<i>IfcRelAggregates</i> relationship.</li>
<li><i>IfcSlab</i> used for all other occurrences of slabs,
particularly for slabs with changing thickness, or slabs with non
planar surfaces, and slabs having only 'SweptSolid' or 'Brep'
geometry.</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC Release 2.0, it is a merger of the two previous entities
IfcFloor, IfcRoofSlab, introduced in IFC Release 1.0</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p>The <i>IfcSlab</i> defines the occurrence of any slab, common
information about slab types (or styles) is handled by
<i>IfcSlabType</i>. The <i>IfcSlabType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common set of properties, common material layer set, and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcSlabType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcSlabType</i> is attached˙(i.e. if only occurrence
information is given) the <i>PredefinedType</i> should be
provided. Values of the enumeration are .FLOOR. (the default),
.ROOF., .LANDING., .BASESLAB. If set to .USERDEFINED. a user
defined value can be provided by the <i>ObjectType</i>
attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcSlab</i> is defined by
<i>IfcMaterialLayerSet</i>, or <i>IfcMaterial</i> and attached by
the <i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It
is accessible by the inverse <i>HasAssociations</i> relationship.
Multi-layer slabs can be represented by referring to several
<i>IfcMaterialLayer</i>'s within the
<i>IfcMaterialLayerSet</i>.</p>
<blockquote><small>NOTE It is illegal to assign an
<i>IfcMaterialLayerSetUsage</i> to an <i>IfcSlab</i>. Only the
subtype <i>IfcSlabStandardCase</i> supports this
concept.</small></blockquote>
<blockquote><small>NOTE Prismatic slabs, where the main face of
the slab is extruded along the slab thickness, are exchanged as
<i>IfcSlabStandardCase</i>, The material for
<i>IfcSlabStandardCase</i> shall be defined
by˙<i>IfcMaterialLayerSetUsage</i>. Multi-layer slabs can be
represented by referring to several <i>IfcMaterialLayer</i>'s
within the <i>IfcMaterialLayerSet</i>.</small>˙</blockquote>
<p>Material information can also be given at the
<i>IfcSlabType</i>, defining the common attribute data for all
occurrences of the same type.˙It is then accessible by the
inverse <i><font color=""#0000FF"">IsTypedBy</font></i>
relationship pointing to <i>IfcSlabType.HasAssociations</i> and
via <i>IfcRelAssociatesMaterial.RelatingMaterial</i>.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcSlab</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcSlab</i> are part
of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_SlabCommon.xml""
target=""SOURCE"">Pset_SlabCommon</a>: common property set for all
slab occurrences</li>
</ul>
<p>Property sets can also be given at the <i>IfcSlabType</i>,
defining the common property data for all occurrences of the same
type.˙It is then accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcSlabType.HasPropertySets</i>. If both are given, then the
properties directly assigned to <i>IfcSlab</i> overrides the
properties assigned to <i>IfcSlabType</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcSlab</i> and
<i>IfcSlabStandardCase</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quantities shall
never be assigned to the <i>IfcSlabType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_SlabBaseQuantities.xml""
target=""SOURCE"">Qto_SlabBaseQuantities</a>: base quantities for
all slab occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcSlab</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierarchical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The˙<i>IfcSlab</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The˙<i>IfcSlab</i> may be aggregated into an element assembly
using the objectified relationship <i>IfcRelAggregates</i>,
referring to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype.<br>
In this case it should not be additionally contained in the
project spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p>The <i>IfcSlab</i><i>˙</i>may also be an aggregate i.e. being
composed by other elements and acting as an assembly using the
objectified relationship <i>IfcRelAggregates</i>, referring to it
by its inverse attribute
<i>SELF\IfcObjectDefinition.IsDecomposedBy</i>. Components of a
slab are described by instances of subtypes of
<i>IfcBuildingElement</i>, with <i>IfcBuildingElementPart</i> as
a special focus subtype that are aggregated to form a complex
slab. In this case, the contained elements should not be
additionally contained in the project spatial hierarchy, i.e. the
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i> of
<i>IfcBuildingElementPart</i> (or other subtypes of
<i>IfcBuildingElement</i>) should be <i>NIL.</i></p>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcSlab</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representation. Included are:</p>
<blockquote><small>NOTE. If the <i>IfcSlab</i> is of type Landing
and is used within an <i>IfcStair</i> or <i>IfcRamp</i>, the
special agreements to handle stair and ramp geometry will also
affect the geometric representation of the
<i>IfcSlab</i>.</small></blockquote>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcSlab</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the placement
of the local placement of the same
<i>IfcSpatialStructureElement</i> that is used in the
<i>ContainedInStructure</i> inverse attribute or to a referenced
spatial structure element at a higher level.</li>
<li>If the <i>IfcSlab</i> is of type Landing and is used by an
<i>IfcStair</i> or <i>IfcRamp</i>, and this container class
defines its own local placement, then the <i>PlacementRelTo</i>
relationship of <i>IfcLocalPlacement</i> shall point (if given)
to the local placement of the aggregate.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the <font color=""#0000FF"">'Surface'</font>,
<font color=""#0000FF"">'FootPrint'</font>, 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>Surface Representation</b></p>
<p>The surfacic geometric representation of <i>IfcSlab</i> is
defined using the 'Surface' representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface3D'</li>
</ul>
<blockquote><small>NOTE The 'Surface' can be used to define a
surfacic model of the building (e.g. for analytical purposes, or
for reduced Level of Detail representation).</small></blockquote>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcSlab</i> can be represented
using the representation types 'SweptSolid', 'Clipping',
'SurfaceModel', and 'Brep'. The representation types
'SurfaceModel' and 'Brep' are explained at
<i>IfcBuildingElement</i>.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<blockquote><small>If a corresponding material definition using
<i>IfcMaterialLayerSetUsage</i> can be assigned, the subtype
<i>IfcSlabStandardCase</i> shall be used.</small></blockquote>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef,
IfcRectangleProfileDef, IfcCircleProfileDef,
IfcEllipseProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile can be extruded perpendicularly
or non-perpendicularly to the plane of the swept profile.</li>
</ul>

<p>Figure 120 illustrates a 'SweptSolid' geometric representation.</p>
<blockquote class=""note"">NOTE The following interpretation of dimension parameter applies for polygonal slabs (in ground floor view):
<ul>
<li><i>IfcArbitraryClosedProfileDef.OuterCurve</i>: closed bounded curve interpreted as area (or foot print) of the slab.</li>
</ul>
</blockquote>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""400""><img src=""figures/IfcSlab_Standard-Layout1.gif"" alt=""standard slab"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 120 &mdash; Slab body extrusion</p></td></tr>
</table>

<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the 'Clipping'
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' shape representation,</li>
<li><u>Profile</u>:˙see 'SweptSolid' shape representation,</li>
<li><u>Extrusion</u>:˙see 'SweptSolid' shape representation,</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i>.</li>
</ul>

<p>Figure 121 illustrates a 'Clipping' geometric representation with definition of a roof slab using advanced
geometric representation. The profile is extruded non-perpendicular and the slab body is clipped at the eave.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""400""><img src=""figures/IfcSlab_Advanced-Layout1.gif"" alt=""advanced slab"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 121 &mdash; Slab body clipping</p></td></tr>
</table>

</EPM-HTML>"
1324;IfcSlabStandardCase;"<EPM-HTML> 
<p>The standard slab,
<i>IfcSlabStandardCase</i>, defines a slab with certain constraints
for the provision of material usage, parameters and with certain
constraints for the geometric representation. The
<i>IfcSlabStandardCase</i> handles all cases of slabs, that:</p>
<ul>
<li>have a reference to the <i>IfcMaterialLayerSetUsage</i>
defining the material layers of the slab with thicknesses</li>
<li>are based on an extrusion of a planar surface as defined by the
slab profile</li>
<li>have a constant thickness along the extrusion direction</li>
<li>are consistent in using the correct material layer set offset
to the base planar surface in regard to the shape
representation</li>
<li>are extruded either perpendicular or slanted to the plane
surface</li>
</ul>
<p>The definitions of slab openings and niches are the same as
given at the supertype <i>IfcSlab</i>. The same agreements to the
special types of slabs, as defined in the <i>PredefinedType</i>
attribute apply as well.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x Edition 4.</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p>The <i>IfcSlabStandardCase</i> defines the occuurence of any
slab, common information about slab types (or styles) is handled by
<i>IfcSlabType</i>. The <i>IfcSlabType</i> (if present) may
establish the common&nbsp;type name, usage (or predefined) type,
common set of properties, common material layer set, and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcSlabType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i> attribute.</p>
<p>The <i>IfcSlabStandardCase</i> defines in addition that the
<i>IfcSlabType</i> should have a unique <i>IfcMaterialLayerSet</i>,
that is referenced by the&nbsp;<i>IfcMaterialLayerSetUsage</i>
assigned to all occurrences of this slab type.</p>

<p>Figure 123 illustrates assignment of <i>IfcMaterialLayerSetUsage</i> and <i>IfcMaterialLayerSet</i> to the <i>IfcSlabStandardCase</i> as the slab occurrence and to the <i>IfcSlabType</i>. The same <i>IfcMaterialLayerSet</i> shall be shared by many occurrences of <i>IfcMaterialLayerSetUsage</i>. This relationship shall be consistent to the relationship between the <i>IfcSlabType</i> and the <i>IfcSlabStandardCase</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" >
<tr><td width=""610"" align=""left"" valign=""top""><img alt=""Material layer set and usage"" src=
""figures/IfcSlab_MaterialUsage-01.png"" height=""220"" width=""501""></td></tr>
<tr><td><p class=""figure"">Figure 123 &mdash; Slab type definition</p></td></tr>
</table>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcSlabStandardCase</i> is defined by
<i>IfcMaterialLayerSetUsage</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Multi-layer slabs can be represented by refering to several
<i>IfcMaterialLayer</i>'s within the <i>IfcMaterialLayerSet</i>
that is referenced from the
<i>IfcMaterialLayerSetUsage</i>.&nbsp;</p>
<p>Material information can also be given at the
<i>IfcSlabType</i>, defining the common attribute data for all
occurrences of the same type.&nbsp;It is then accessible by the
inverse <i>IsDefinedBy</i> relationship pointing to
<i>IfcSlabType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i>. See <b>Type Use
Definition</b> for additional agreements for standard slabs.</p>

<p>Figure 123 illustrates slab material usage, where the following conventions shall be met:</p>
<ul>
<li>The reference coordinate system is the coordinate system established by the <i>IfcExtrudedAreaSolid.Position</i>.</small></li>
<li><small>The reference plane is the plane defined by the extruded profile of <i>IfcExtrudedAreaSolid.SweptSolid</i>. The <i>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</i> is given as a distance from this plane.</li>
<li>The <i>IfcMaterialLayerSetUsage.DirectionSense</i> defines how the <i>IfcMaterialLayer</i>'s are assigned to the reference plane. POSITIVE means in direction to the positive z-axis of the reference coordinate system.</li>
<li>The <i>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</i> is the distance parallel to the reference plane and always perpendicular to the base (XY) plane of the reference coordinate system. This is independent of a potential non-perpendicular extrusion given by <i>IfcExtrudedAreaSolid.ExtrudedDirection</i> &lt;&gt; 0.,0.,1. A positive value of <i>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</i> would then point into the positive z-axis of the reference coordinate system.</li>
<li>The <i>Thickness</i> of each <i>IfcMaterialLayer</i> shall be the parallel distance (measured perpendicular to the base plane). The <i>TotalThickness</i> of the <i>IfcMaterialLayerSet</i> is the sum of all layer thicknesses and in case of a perpendicular extrusion identical with <i>IfcExtrudedAreaSolid.Depth</i></li>
<li>The <i>IfcMaterialLayerSetUsage.LayerSetDirection</i> is always AXIS3.</li>
</ul>

<table summary=""material use definition for standard slabs"" border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top"" width=""610"">
<img src=""figures/IfcMaterialLayerSetUsage_Slab-01.png"" alt=
""slab material layer set"" width=""601"" height=""321"" border=""0"">
</td></tr>
<tr><td align=""left"" valign=""top"" width=""610"">
<img src=""figures/IfcMaterialLayerSetUsage_RoofSlab-01.png"" alt=
""roof slab material layer set"" width=""600"" height=""400"" border=
""0""></td></tr>
<tr><td><p class=""figure"">Figure 124 &mdash; Slab material layers</p></td></tr>
</table>

<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcSlabStandardCase</i> are
defined at the supertype <i>IfcSlab</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcSlabStandardCase</i> are
defined at the supertype <i>IfcSlab</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcSlabStandardCase</i> are defined at the supertype
<i>IfcSlab</i>.</p>

<p><u><b>Geometry Use Definitions</b></u></p>
<p>The geometric representation of <i>IfcSlabStandardCase</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation. Included are:</p>
<blockquote>
<p><small>NOTE If the <i>IfcSlabStandardCase</i> is of type Landing
and is used within an <i>IfcStair</i> or <i>IfcRamp</i>, the
special agreements to handle stair and ramp geometry will also
affect the geometric representation of the
<i>IfcSlabStandardCase</i>.</small></p>
</blockquote>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcSlab</i>.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of 'SweptSolid' and 'Clipping'
representations is supported. In addition the general
representation type 'BoundingBox' is allowed. The geometry use
definitions for 'BoundingBox', is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>SweptSolid Representation</b></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used for the 'SweptSolid' representation:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef,
IfcRectangleProfileDef, IfcCircleProfileDef,
IfcEllipseProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile can be extruded perpendicularly
or non-perpendicularly to the plane of the swept profile.</li>
<li><u>Material</u>: The definition of the
<i>IfcMaterialLayerSetUsage</i>, particularly of the
<i>OffsetFromReferenceLine</i> and the
<i>ForLayerSet.TotalThickness</i>, has to be consistent to the
'SweptSolid' representation.</li>
</ul>

<p>Figure 125 illustrates a 'SweptSolid' geometric representation.</p>
<blockquote class=""note"">NOTE The following interpretation of dimension parameter applies for polygonal slabs (in ground floor view):
<ul>
<li><i>IfcArbitraryClosedProfileDef.OuterCurve</i>: closed bounded curve interpreted as area (or foot print) of the slab.</li>
</ul>
</blockquote>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""420""><img src=""figures/IfcSlab_Standard-Layout1.gif"" alt=""standard slab"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 125 &mdash; Slab body extrusion</p></td></tr>
</table>

<p><b>Clipping representation</b></p>
<p>The 'Clipping' geometric representation of
<i>IfcSlabStandardCase</i> is defined using the swept area geometry
with additional clippings applied. The following attribute values
for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the 'Clipping'
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' shape representation,</li>
<li><u>Profile</u>:&nbsp;see 'SweptSolid' shape
representation,</li>
<li><u>Extrusion</u>:&nbsp;see 'SweptSolid' shape
representation,</li>
<li><u>Material</u>:&nbsp;see 'SweptSolid' shape
representation,</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i>.</li>
</ul>

<p>Figure 126 illustrates a 'Clipping' geometric representation with definition of a roof slab using advanced geometric representation. The profile is extruded non-perpendicular and the slab body is clipped at the eave.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""420""><img src=
""figures/IfcSlab_Advanced-Layout1.gif"" alt=""advanced slab"" border=
""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 126 &mdash; Slab body clipping</p></td></tr>
</table>

</EPM-HTML>"
1326;IfcSlabElementedCase;"<EPM-HTML>
<p>The <i>IfcSlabElementedCase</i>
defines a slab with certain constraints for the provision of its
components. The <i>IfcSlabElementedCase</i> handles all cases of
slabs, that are decomposed into parts:˙</p>
<ul>
<li>having components being assigned to the
<i>IfcSlabElementedCase</i> using the <i>IfcRelAggregates</i>
relationship accessible by the inverse relationship
<i>IsDecomposedBy</i>.</li>
<li>applying the constraint that the parts within the
decomposition shall be of type <i>IfcBeam</i>, <i>IfcMember</i>,
<i>IfcPlate</i>, <i>IfcBuildingElementPart</i> or
<i>IfcBuildingElementProxy</i>.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4.</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcSlabElementedCase</i>
are defined at the supertype <i>IfcSlab</i>.</p>
<blockquote><small>NOTE The parts within the decomposition
relationship may define their own property
sets.</small></blockquote>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcSlabElementedCase</i> are
defined at the supertype <i>IfcSlab</i>.</p>
<blockquote><small>NOTE The parts within the decomposition
relationship may define their own individual
quantities.</small></blockquote>

<p><u><b>Voiding Use Definition</b></u>:</p>

<p>As shown in Figure 122, openings within the composite slab are directly assigned to <i>IfcSlabElementedCase</i> using <i>IfcRelVoidsElement</i> pointing to <i>IfcOpeningElement</i> and apply to all aggregated parts. If individual parts have cutting and other voiding features, then the decomposed parts have a separate voiding relationship <i>IfcRelVoidsElement</i> pointing to <i>IfcVoidingFeature</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""voiding"">
<tr><td valign=""top""><img src=""figures/IfcSlabElementedCase_fig01.png"" alt=""voiding"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 122 &mdash; Slab elemented voiding</p></td></tr>
</table>

<p><u><b>Decomposition Use Definition</b></u>:</p>
<p>The following guidance is provided for the components of the
<i>IfcSlabElementedCase</i>. The following component entity types
should be used:</p>
<ul style=""list-style-type:none"">
<li>Precast hollow core slabs
<ul style=""list-style-type:square"">
<li>double tee or plank components : <i>IfcBeam</i></li>
<li>topping : <i>IfcBuildingElementPart</i></li>
<li>others : <i>IfcBuildingElementPart</i></li>
</ul>
</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcSlabElementedCase</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcSlab</i>. The local placement of the
<i>IfcSlabElementedCase</i> defines the parent coordinate systems
for the parts within the decomposition. All parts shall be
positioned relative to the <i>IfcSlabElementedCase</i>.</p>
<p><b><i>Geometric Representation</i></b></p>
<p>The standard geometric representation of
<i>IfcSlabElementedCase</i> is defined using the following
multiple shape representations for its definition:</p>
<ul>
<li><u>Surface</u>: A three-dimensional surface being a subtype
of <i>IfcBoundedSurface</i> defining the reference surface for
the elemented slab. It maybe used as a simplified representation
directly at the elemented slab.</li>
</ul>
<blockquote><small>NOTE˙ It is invalid to exhange a 'Body' shape
representation of an <i>IfcSlabElementedCase</i>. The body
geometry is defined by the parts within the
decomposition.</small></blockquote>
<p><b>Surface Representation</b></p>
<p>The surfacic geometric representation of
<i>IfcSlabElementedCase</i> is defined using the 'Surface'
representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface3D'</li>
</ul>
<blockquote><small>NOTE The 'Surface' can be used to define a
surfacic model of the building (e.g. for analytical purposes, or
for reduced Level of Detail representation). It should suppress
the geometric details of the parts in the
decomposition.</small></blockquote>
</EPM-HTML>"
1335;IfcRamp;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Inclined way or floor
joining two surfaces at different levels.</p>
<p>A ramp is a vertical passageway which
provides a human circulation link between one floor level and
another floor level at a different elevation. It may include a
landing as an intermediate floor slab. A ramp normally does not
include steps (stepped ramps are out of scope for this IFC
Release).</p>
<p>The ramp is a container entity that aggregates all components
of the ramp, it represents. The aggregation is handled via the
<i>IfcRelAggregates</i> relationship, relating an <i>IfcRamp</i>
with the related flights (<i>IfcRampFlight</i>) and landings
(<i>IfcSlab</i> with type 'Landing'). Railings belonging to the
ramp may be included into the aggregation as
<i>IfcRailing</i>.</p>

<blockquote class=""history"">HISTORY New Entity in IFC Release 2.0.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE Attribute ShapeType renamed to <i>PredefinedType</i></blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcRamp</i> defines the occuurence of any ramp, common
information about ramp types (or styles) is handled by
<i>IfcRampType</i>. The <i>IfcRampType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material, common set of properties and common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcRampType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<blockquote><small>NOTE Since the <i>IfcRamp</i> might be
represented as an aggregate of parts, e.g. represented by
<i>IfcRampFlight</i>, or <i>IfcSlab</i>, these individual parts
may have type information attached (represented e.g. by
<i>IfcRampFlightType</i>, or
<i>IfcSlabType</i>).</small></blockquote>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcRamp</i> is defined by the
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p>Material information can also be given at the
<i>IfcRampType</i>, defining the common attribute data for all
occurrences of the same type.˙It is then accessible by the
inverse <i>IsDefinedBy</i> relationship pointing to
<i>IfcRampType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterial</i>. If both are given, then the material directly
assigned to <i>IfcRamp</i> overrides the material assigned to
<i>IfcRampType</i>.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcRamp</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcRamp</i> are part
of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_RampCommon.xml""
target=""SOURCE"">Pset_RampCommon</a>: common property set for all
ramp occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcRamp</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.MethodOfMeasurement</i> = 'BaseQuantities'.
Other quantities can be defined being subjected to local standard
of measurement with another string value assigned to <i>Name</i>
and a value provided for <i>MethodOfMeasurement</i>. Quantities
shall never be assigned to the <i>IfcRampType</i>.</p>
<p>The individual quantities shall only be given at
<i>IfcRamp</i>, it is not decomposed into the individual parts,
<i>IfcRampFlight</i> and <i>IfcSlab</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_RampBaseQuantities.xml""
target=""SOURCE"">Qto_RampBaseQuantities</a>: base quantities for
all ramp occurrences.</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcRamp</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Independent geometric representations should
only be used when the <i>IfcRamp</i> is not defined as an
aggregate. If defined as an aggregate, the geometric
representation is the sum of the representation of the components
within the aggregate.</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcRamp</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p>If the <i>LocalPlacement</i> is given for the <i>IfcRamp</i>,
then all components, which are aggregated to the ramp should use
this placement as their relative placement.</p>
<p><b><i>Geometric representations</i></b></p>
<p><i>Geometric representation by own shape
representation</i></p>
<p>If the <i>IfcRamp</i> has no components defined (empty set of
<i>SELF\IfcProduct.IsDecomposedBy</i>) then the <i>IfcRamp</i>
may be represented by an own <i>IfcShapeRepresentation</i> with
the following values:</p>
<ul>
<li>RepresentationIdentifier : 'Body'</li>
<li>RepresentationType : 'SweptSolid', 'Clipping',
'SurfaceModel', or 'Brep'</li>
</ul>
<p>The conventions to use these representations are provided at
<i>IfcBuildingElement</i>. No further constraints or provisions
on how to use the representation types are defined for
<i>IfcRamp</i>.</p>
<p><i>Geometric representation by aggregated elements</i></p>
<p>If the <i>IfcRamp</i> has components (referenced by
<i>SELF\IfcProduct.IsDecomposedBy</i>) then no independent
geometric representation shall be defined for the <i>IfcRamp</i>.
The <i>IfcRamp</i> is then geometrically represented by the
geometric representation of its components. The components are
accessed via
<i>SELF\IfcProduct.IsDecomposedBy[1].RelatedObjects</i>.</p>

<p>Figure 111 illustrates <i>IfcRamp</i> defining the local placement for all components.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td valign=""top"" align=""left""><img src=
""figures/IfcRamp-Layout1.gif"" alt=""ramp"" width=""393"" height=""299""
border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 111 &mdash; Ramp placement</p></td></tr>
</table>

</EPM-HTML>"
1349;IfcStair;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Construction comprising
a succession of horizontal stages (steps or landings) that make it
possible to pass on foot to other levels.</p>
<p>A stair is a vertical passageway allowing
occupants to walk (step) from one floor level to another floor
level at a different elevation. It may include a landing as an
intermediate floor slab. The stair should either be
represented:</p>
<ul>
<li>as a stair assembly entity that aggregates all components
(stair flight, landing, etc. with own representations), or</li>
<li>as a single stair entity without decomposition including all
representation directly at the stair entity.</li>
</ul>
<p>In case of a stair container, the aggregation is handled via the
<i>IfcRelAggregates</i> relationship, relating an <i>IfcStair</i>
with the related <i>IfcStairFlight</i>'s and landings (represented
by <i>IfcSlab</i> with <i>IfcSlab.PredefinedType</i> = 'LANDING').
<i>IfcRailing</i>'s belonging to the stair may be included into the
aggregation as well.</p>

<blockquote class=""history"">HISTORY New Entity in IFC Release 2.0.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE Attribute ShapeType renamed to <i>PredefinedType</i>.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcStair</i> defines the occurrence of any stair, common
information about stair types (or styles) is handled by
<i>IfcStairType</i>. The <i>IfcStairType</i> (if present) may
establish the common type name, usage (or predefined) type, common
material, common set of properties and common shape representations
(using <i>IfcRepresentationMap</i>). The <i>IfcStairType</i> is
attached using the <i>IfcRelDefinedByType.RelatingType</i>
objectified relationship and is accessible by the inverse
<i>IsDefinedBy</i> attribute.</p>
<blockquote><small>NOTE Since the <i>IfcStair</i> might be
represented as an aggregate of parts, e.g. represented by
<i>IfcStairFlight</i>, or <i>IfcSlab</i>, these individual parts
may have type information attached (represented e.g. by
<i>IfcStairFlightType</i>, or
<i>IfcSlabType</i>).</small></blockquote>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcStair</i> is defined by the
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.</p>
<p>Material information can also be given at the
<i>IfcStairType</i>, defining the common attribute data for all
occurrences of the same type. It is then accessible by the inverse
<i>IsDefinedBy</i> relationship pointing to
<i>IfcStair.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterial</i>. If both are given, then the material directly
assigned to <i>IfcStair</i> overrides the material assigned to
<i>IfcStairType</i>.</p>

<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcStair</i> are defined by
the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcStair</i> are part of this
IFC release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_StairCommon.xml""
target=""SOURCE"">Pset_StairCommon</a>: common property set for all
stair occurrences</li>
</ul>

<p>Figure 127 shows the use of property sets Pset_StairCommon and
Pset_StairFlightCommon for the various stair properties.</p>

<table>
<tr><td><img src=""figures/IfcStair_Parameter.png"" alt=""stair properties""
border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 127 &mdash; Stair properties</p></td></tr>
</table>

<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcStair</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representation. Independent geometric representations should only
be used when the IfcStair is not defined as an aggregate. If
defined as an aggregate, the geometric representation is the sum of
the representation of the components within the aggregate.</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcStair</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p>If the <i>LocalPlacement</i> is given for the <i>IfcStair</i>,
then all components, which are aggregated to the stair should use
this placement as their relative placement.</p>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the 'Axis', 'FootPrint', 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
IfcBuildingElement.</p>
<ul>
<li><u>Axis</u>: A two-dimensional open curve
<i>IfcBoundedCurve</i> defining the walking line for the
stair.</li>
<li><u>FootPrint</u>: A geometric curve set defining the footing
print, including the boundary of the stair.</li>
<li><u>Body</u>: A solid representation defining the 3D shape of
the stair.</li>
</ul>
<p><b>Axis Representation</b></p>
<p>The walking line is represented by a two-dimensional open curve
as the axis. The curve is directed into the upward direction
(direction has to be interpreted as specified at the subtypes of
<i>IfcCurve</i>). The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D'</li>
</ul>
<blockquote>
<p><small>NOTE&nbsp; The 'Axis' representation of <i>IfcStair</i>
may be provided even if the <i>IfcStair</i> has components with own
shape representations.</small></p>
</blockquote>
<p><b>FootPrint Representation</b></p>
<p>The stair foot print, including the stair boundary is
represented by a two-dimensional geometric curve set. The following
attribute values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet'</li>
</ul>
<blockquote>
<p><small>NOTE&nbsp; The 'Footprint' representation of
<i>IfcStair</i> may be provided even if the <i>IfcStair</i> has
components with own shape representations.</small></p>
</blockquote>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcStair</i> can be represented
using the representation types 'SweptSolid', 'SurfaceModel',
'Brep', and 'MappedRepresentation'. The general usage of
representation is are explained at <i>IfcBuildingElement</i>. No
further constraints or provisions on how to use the representation
types are defined for <i>IfcStairFlight</i>.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid', 'SurfaceModel',
'Brep', 'MappedRepresentation'</li>
</ul>
<p>The 'Body' representation shall only be provided if the
<i>IfcStair</i> has no components defined (empty set of
<i>SELF\IfcObject.IsDecomposedBy</i>) or if the components defined
no not carry an own 'Body' representation.</p>
<p><i>Geometric representation by aggregated elements</i></p>
<p>If the <i>IfcStair</i> has components (referenced by
<i>SELF\IfcObject.IsDecomposedBy</i>) with own 'Body'
representation, then no 'Body' representation shall defined for the
<i>IfcStair</i>. The <i>IfcStair</i> shape is then represented by
the geometric representation of its components. The components are
accessed via
<i>SELF\IfcObject.IsDecomposedBy[1].RelatedObjects</i>.</p>

<p>Figure 128 illustrates stair placement, where the <i>IfcStair</i> defines the local placement for all components and the common 'Axis' representation, and each component has its own 'Body' representation.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcStair-Layout1.png"" alt=""stair"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 128 &mdash; Stair placement</p></td></tr>
</table>

</EPM-HTML>"
1371;IfcRoof;"<EPM-HTML> 

<p><u>Definition from ISO 6707-1:1989</u>: Construction enclosing the building from above.</p>
<p>The <i>IfcRoof</i> is a description of the total roof. It acts as a container entity, that aggregates all components of the roof, it represents. The aggregation is handled via the <i>IfcRelAggregates</i> relationship, relating an <i>IfcRoof</i> with the related roof elements, like slabs (represented by <i>IfcSlab</i>), rafters and purlins (represented by <i>IfcBeam</i>), or other included roofs, such as dormers (represented by <i>IfcRoof</i>).</p>

<blockquote class=""history"">HISTORY New Entity in IFC Release 2.0.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE Attribute ShapeType renamed to <i>PredefinedType</i>.</blockquote>

<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcRoof</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcRoof</i> are part
of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_RoofCommon.xml""
target=""SOURCE"">Pset_RoofCommon</a>: common property set for all
roof occurrences</li>
</ul>
<p>The quantities relating to the <i>IfcRoof</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.MethodOfMeasurement</i> = 'BaseQuantities'.
Other quantities can be defined being subjected to local standard
of measurement with another string value assigned to <i>Name</i>
and a value provided for <i>MethodOfMeasurement</i>. Quantities
shall never be assigned to the <i>IfcRoofType</i>.</p>
<p>The individual quantities shall only be given at
<i>IfcRoof</i>, it is not decomposed into the individual parts,
e.g. <i>IfcSlab</i> as roof slabs.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_RoofBaseQuantities.xml""
target=""SOURCE"">Qto_RoofBaseQuantities</a>: base quantities for
all roof occurrences.</li>
</ul>
<p><b><u>Containment Use Definition</u></b></p>
<p>The <i>IfcRoof</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the
aggregation within an element assembly.</p>
<ul>
<li>The <i>IfcRoof</i> is placed within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of <i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcRoof</i> may be aggregated into an element assembly
using the objectified relationship <i>IfcRelAggregates</i>,
referring to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcRoof</i>, the overall roof, as a special focus subtype. In
this case it should not be additionally contained in the project
spatial hierarchy, i.e.
<i>SELF\IfcElement.ContainedInStructure</i> should be NIL.</li>
</ul>
<blockquote><small>NOTE˙ A roof contained in another roof could
be the representation of a dormer.</small></blockquote>
<p>The <i>IfcRoof</i> may be an aggregate i.e. being composed by
other elements and acting as an assembly using the objectified
relationship <i>IfcRelAggregates</i>, referring to it by its
inverse attribute <i>SELF\IfcObjectDefinition.IsDecomposedBy</i>.
Components of a roof are described by instances of subtypes of
<i>IfcBuildingElement</i> (e.g. <i>IfcSlab</i>, <i>IfcBeam</i>,
<i>IfcColumn</i>, <i>IfcBuildingElementPart</i>) that are
aggregated to form a complex roof. In this case, the contained
elements should not be additionally contained in the project
spatial hierarchy, i.e. the inverse attribute
<i>SELF\IfcElement.ContainedInStructure</i> of the aggregated
elements should be NIL.</p>

<p>Figure 118 illustrates roof containment, where only the <i>IfcRoof</i> as the aggregate
is included in the spatial structure.</p>

<table summary=""containment usage"">
<tr><td valign=""top""><img src=""figures/IfcRoof_Containment-01.png"" alt=""Containment"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 118 &mdash; Roof containment</p></td></tr>
</table>

<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcRoof</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Independent geometric representations should
only be used when the <i>IfcRoof</i> is not defined as an
aggregate. If defined as an aggregate, the geometric
representation is the sum of the representation of the components
within the aggregate.</p>
<blockquote><small>NOTE˙ View definitions and implementer
agreements may restrict the <i>IfcRoof</i> to not have an
independent geometry, but to always require aggregated elements
to represent the shape of the roof.</small><br>
<small>NOTE If the <i>IfcRoof</i> has aggregated elements to
represent the shape of the roof, then only those elements shall
have openings, not the <i>IfcRoof</i>
itself.</small></blockquote>
<p><b>Local Position</b></p>
<p>The local placement for <i>IfcRoof</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level..</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p>If the <i>LocalPlacement</i> is given for the <i>IfcRoof</i>,
then all components, which are aggregated to the roof should use
this placement as their relative placement.</p>
<p><b><i>Geometric Representation</i></b></p>
<p>The IfcRoof may have an independent geometric representation
or may be an aggregate with elements holding the geometric
representation of the roof.</p>
<p><i>Geometric representation by own shape
representation</i></p>
<p>If the <i>IfcRoof</i> has no components defined (empty set of
<i>SELF\IfcObject.IsDecomposedBy</i>) then the <i>IfcRoof</i> may
be represented by an independent <i>IfcShapeRepresentation</i>.
The following attribute values for the IfcShapeRepresentation
holding this geometric representation shall be used:</p>
<ul>
<li>RepresentationIdentifier : 'Body'</li>
<li>RepresentationType : 'SweptSolid', 'Clipping',
'SurfaceModel', or 'Brep'</li>
</ul>
<p><i>Geometric representation by aggregated elements</i></p>
<p>If the <i>IfcRoof</i> has components (referenced by
<i>SELF\IfcObject.IsDecomposedBy</i>) then no independent
geometric representation shall defined for the <i>IfcRoof</i>.
The <i>IfcRoof</i> is then geometrically represented by the
geometric representation of its components. The components are
accessed via
<i>SELF\IfcObject.IsDecomposedBy[1].RelatedObjects</i>. The
geometric representations that are supported for the aggregated
elements are defined with each element. See geometric use
definition for <i>IfcSlab</i>, <i>IfcBeam</i>, <i>IfcColumn</i>,
<i>IfcBuildingElementPart</i> and other subtypes of
<i>IfcBuildingElement</i>.</p>

<p>Figure 119 illustrates roof placement, with an <i>IfcRoof</i> defining the local placement for all aggregated elements.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td valign=""top"" align=""left""><img src=""figures/IfcRoof-Layout1.gif"" alt=""roof"" width=""399"" height=""274"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 119 &mdash; Roof placement</p></td></tr>
</table>

</EPM-HTML>"
1392;IfcStairFlight;"<EPM-HTML> 
<p>A stair flight is an assembly of
building components in a single ""run"" of stair steps (not
interrupted by a landing). The stair steps and any stringers are
included in the stair flight. A winder is also regarded a part of
a stair flight.</p>
<p>An <i>IfcStairFlight</i> is normally aggregated by an
<i>IfcStair</i> through the <i>IfcRelAggregates</i> relationship,
the stair flight is then included in the set of
<i>IfcRelAggregates.RelatedObjects</i>. An <i>IfcStairFlight</i>
normally connects the floor slab of zero to two different storeys
(or partial storeys, or landings) within a building. The
connection relationship between the <i>IfcStairFlight</i> and the
<i>IfcSlab</i> is expressed using the
<i>IfcRelConnectsElements</i> relationship.</p>

<blockquote class=""history"">HISTORY: New Entity in IFC Release 2.0.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcStairFlight</i> defines the occurrence of any stair
flight, common information about stair flight types (or styles)
is handled by <i>IfcStairFlightType</i>. The
<i>IfcStairFlightType</i> (if present) may establish the
common˙type name, usage (or predefined) type, common material
layer set, common set of properties and common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcStairFlightType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcStairFlight</i> is defined by the
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcStairFlight</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcStairFlight</i>
are part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_StairFlightCommon.xml""
target=""SOURCE"">Pset_StairFlightCommon</a>: common property set
for all stair flight occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcStairFlight</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quantities shall
never be assigned to the <i>IfcStairFlightType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_StairFlightBaseQuantities.xml""
target=""SOURCE"">Qto_StairFlightBaseQuantities</a>: base
quantities for all stair flight occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcStairFlight</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first relationship is the
hierachical spatial containment, the second relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcStairFlight</i> is placed within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcStairFlight</i> may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcStair</i> as a special focus subtype. In this case it
shall not be additionally contained in the project spatial
hierarchy, i.e.˙<i>SELF\IfcElement.ContainedInStructure</i>
shall be <i>NIL.</i></li>
</ul>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcStairFlight</i> is given
by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation. Included are:</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcStairFlight</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the <i>IfcStairFlight</i>, however, is used by an
<i>IfcStair</i>, and this container class defines its own local
placement, then the <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement of
the <i>IfcStair</i>.</li>
</ul>
<p><b>Geometric Representations</b></p>
<p>Currently, the 'Axis', 'FootPrint', 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<ul>
<li><u>Axis</u>: A two-dimensional open curve
<i>IfcBoundedCurve</i> defining the walking line for the stair
flight.</li>
<li><u>FootPrint</u>: A geometric curve set defining the footing
print, including the boundary of the stair flight.</li>
<li><u>Body</u>: A solid representation defining the 3D shape of
the stair flight</li>
</ul>
<p><b>Axis Representation</b></p>
<p>The walking line is represented by a two-dimensional open
curve as the axis. The curve is directed into the upward
direction (direction has to be interpreted as specified at the
subtypes of <i>IfcCurve</i>). The following attribute values for
the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D'</li>
</ul>

<p>Figure 129 illustrates the axis representation which has the following constraints:</p>
<ul>
<li>In case of straight flights the curve shall be a single item of type <i>IfcPolyline</i>.</li>
<li>In case of winding flights the curve shall be a single item of type <i>IfcCompositeCurve</i>.</li>
<li>In case of a curved flight or a spiral flight the curve shall be a single item of type <i>IfcTrimmedCurve</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcStairFlight_01-Layout1.gif"" alt=""walking line"" width=""393"" height=""299"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 129 &mdash; Stair flight axis</p></td></tr>
</table>

<p><b>FootPrint Representation</b></p>
<p>The flight foot print, including the flight boundary is
represented by a two-dimensional geometric curve set. The
following attribute values for the <i>IfcShapeRepresentation</i>
holding this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet'</li>
</ul>

<p>Figure 130 illustrates the footprint representation which has the following constraints:</p>
<ul>
<li>In case of straight flights the curve set shall consists of a single item of type <i>IfcPolyline</i>.</li>
<li>In case of winding flights or curved flights the curve set shall consists of a single item of type <i>IfcCompositeCurve</i>.</li>
<li>In case of a spiral flight the curve set shall consists of a single item of type <i>IfcConic</i> or <i>IfcPolyline</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcStairFlight_02-Layout1.gif"" alt=""boundary"" width=""393"" height=""299"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 130 &mdash; Stair flight footprint</p></td></tr>
</table>

<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcStairFlight</i> can be represented using the representation types 'SweptSolid', 'SurfaceModel', 'Brep', and 'MappedRepresentation'. The general usage of representation is are explained at
<i>IfcBuildingElement</i>. No further constraints or provisions on how to use the representation types are defined for
<i>IfcStairFlight</i>.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid', 'SurfaceModel', 'Brep', 'MappedRepresentation'</li>
</ul>
<p>Figure 131 illustrates the body representation.</p>
<table cellpadding=""2"" cellspacing=""2"">
<tr><td valign=""top"" align=""left""><img src=""figures/IfcStairFlight_03-Layout1.gif"" alt=""3D"" width=""393"" height=""299"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 131 &mdash; Stair flight body</p></td></tr>
</table>
</EPM-HTML>"
1408;IfcRampFlight;"<EPM-HTML> 
<p>A ramp is an inclined slab segment, normally
providing a human circulation link between two landings, floors or
slabs at different elevations.</p>
<p>An <i>IfcRampFlight</i> is normally aggregated by an
<i>IfcRamp</i> through the <i>IfcRelAggregates</i> relationship,
the ramp flight is then included in the set of
<i>IfcRelAggregates.RelatedObjects</i>. An <i>IfcRampFlight</i>
normally connects the floor slab of zero to two different storeys
(or partial storeys or landings) within a building. The connection
relationship between the <i>IfcRampFlight</i> and the
<i>IfcSlab</i> is expressed using the <i>IfcRelConnectsElements</i>
relationship.</p>
<blockquote class=""history"">HISTORY New Entity in IFC Release 2.0.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcRampFlight</i> defines the occurrence of any ramp flight,
common information about ramp flight types (or styles) is handled
by <i>IfcRampFlightType</i>. The <i>IfcRampFlightType</i> (if
present) may establish the common&nbsp;type name, usage (or
predefined) type, common material layer set, common set of
properties and common shape representations (using
<i>IfcRepresentationMap</i>). The <i>IfcRampFlightType</i> is
attached using the <i>IfcRelDefinedByType.RelatingType</i>
objectified relationship and is accessible by the inverse
<i>IsDefinedBy</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcRampFlight</i> is defined by the
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcRampFlight</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcRampFlight</i> are part of
this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_RampFlightCommon.xml"" target=
""SOURCE"">Pset_RampFlightCommon</a>: common property set for all
ramp flight occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcRampFlight</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities
can be defined being subjected to local standard of measurement
with another string value assigned to <i>Name</i> and a value
provided for <i>MethodOfMeasurement</i>. Quantities shall never be
assigned to the <i>IfcRampFlightType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_RampFlightBaseQuantities.xml""
target=""SOURCE"">Qto_RampFlightBaseQuantities</a>: base quantities
for all ramp flight occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcRampFlight</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first relationship is the
hierachical spatial containment, the second relationship is the
aggregation within an&nbsp;element assembly.</p>
<ul>
<li>The <i>IfcRampFlight</i> is placed within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of&nbsp;<i>IfcSpatialStructureElement</i> are valid
spatial containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcRampFlight</i> may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with <i>IfcRamp</i>
as a special focus subtype. In this case it should not be
additionally contained in the project spatial hierarchy,
i.e.&nbsp;<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcRampFlight</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Included are:</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcRampFlight</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the <i>IfcRampFlight</i>, however, is used by an
<i>IfcRamp</i>, and this container class defines its own local
placement, then the <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement of the
<i>IfcRamp</i>.</li>
</ul>
<p><b>Geometric Representations</b></p>
<p>Currently, the 'Axis', 'FootPrint', 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<ul>
<li><u>Axis</u>: A two-dimensional open curve
<i>IfcBoundedCurve</i> defining the walking line for the ramp
flight.</li>
<li><u>FootPrint</u>: A geometric curve set defining the footing
print, including the boundary of the ramp flight.</li>
<li><u>Body</u>: A solid representation defining the 3D shape of
the ramp flight</li>
</ul>
<p><b>Axis Representation</b></p>
<p>The walking line is represented by a two-dimensional open curve
as the axis. The curve is directed into the upward direction
(direction has to be interpreted as specified at the subtypes of
<i>IfcCurve</i>). The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D'</li>
</ul>

<p>Figure 112 illustrates the axis representation which has the following constraints:</p>
<ul>
<li>In case of straight flights the curve shall be a single item of type <i>IfcPolyline</i>.</li>
<li>In case of winding flights the curve shall be a single item of type <i>IfcCompositeCurve</i>.</li>
<li>In case of a curved flight or a spiral flight the curve shall be a single item of type <i>IfcTrimmedCurve</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcStairFlight_01-Layout1.gif"" alt=""walking line"" width=""393"" height=""299"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 112 &mdash; Ramp flight axis</p></td></tr>
</table>

<p><b>FootPrint Representation</b></p>
<p>The flight foot print, including the flight boundary is represented by a two-dimensional geometric curve set. The following attribute values for the <i>IfcShapeRepresentation</i> holding this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet'</li>
</ul>

<p>Figure 113 illustrates the footprint representation which has the following constraints:</p>
<ul>
<li>In case of straight flights the curve set shall consist of a single item of type <i>IfcPolyline</i>.</li>
<li>In case of winding flights or curved flights the curve set shall consists of a single item of type
<i>IfcCompositeCurve</i>.</li>
<li>In case of a spiral flight the curve set shall consists of a single item of type <i>IfcConic</i> or
<i>IfcPolyline</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcStairFlight_02-Layout1.gif"" alt=""boundary"" width=""393"" height=""299"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 113 &mdash; Ramp flight footprint</p></td></tr>
</table>

<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcRampFlight</i> can be
represented using the representation types 'SweptSolid',
'SurfaceModel', 'Brep', and 'MappedRepresentation'. The general
usage of representation is are explained at
<i>IfcBuildingElement</i>. For further constraints on the
'SweptSolid' the representation types see below..</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid', 'SurfaceModel',
'Brep', 'MappedRepresentation'</li>
</ul>
<p><i>SweptSolid Representation Type</i></p>
<p>The 'SweptSolid' representation type is a valid body
representation of <i>IfcRampFlight</i> is defined using the swept
area geometry. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation type:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded in any
direction relative to the XY plane of the position coordinate
system of the <i>IfcExtrudedAreaSolid</i>. Therefore
non-perpendicular sweep operation has to be supported. It might be
further constrained to be in the direction of the global z-axis in
implementers agreements.</li>
</ul>

<p>Figure 114 illustrates the body representation.</p>
<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td valign=""top"" align=""left""><img src=""figures/IfcRampFlight-Layout1.gif"" alt=""fig1"" width=""393"" height=""299"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 114 &mdash; Ramp flight body</p></td></tr>
</table>

</EPM-HTML>"
1417;IfcCurtainWall;"<EPM-HTML>
<p><u>Definition from ISO 6707-1:1989</u>: Non load bearing wall
positioned on the outside of a building and enclosing it.</p>
<p>A curtain wall is an exterior wall of a building which is
an assembly of components, hung from the edge of the floor/roof
structure rather than bearing on a floor. Curtain wall is
represented as a building element assembly and implemented as a
subtype of <i>IfcBuildingElement</i> that uses an
<i>IfcRelAggregates</i> relationship.</p>
<blockquote class=""history"">HISTORY New Entity in IFC Release 2.0</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcCurtainWall</i> defines the occuurence of any curtain
wall, common information about curtain wall types (or styles) is
handled by <i>IfcCurtainWallType</i>. The
<i>IfcCurtainWallType</i> (if present) may establish the
common˙type name, usage (or predefined) type, common material
information, common set of properties and common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcCurtainWallType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p>If no <i>IfcCurtainWallType</i> is attached˙(i.e. if only
occurrence information is given) the predefined type may be given
by using the <i>ObjectType</i> attribute.</p>
<blockquote><small>NOTE Since the <i>IfcCurtainWall</i> might be
represented as an aggregate of parts, e.g. represented by
<i>IfcMember</i>, or <i>IfcPlate</i>, these individual parts may
have type information attached (represented e.g. by
<i>IfcMemberType</i>, or
<i>IfcPlateType</i>).</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcCurtainWall</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcCurtainWall</i>
are part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CurtainWallCommon.xml""
target=""SOURCE"">Pset_CurtainWallCommon</a>: common property set
for all curtain wall occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcCurtainWall</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quantities shall
never be assigned to the <i>IfcCurtainWallType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_CurtainWallBaseQuantities.xml""
target=""SOURCE"">Qto_CurtainWallBaseQuantities</a>: base
quantities for all curtain wall occurrences.</li>
</ul>
<p><u><b>Geometry Use Definitions</b>:</u></p>
<p>The geometric representation of <i>IfcCurtainWall</i> is given
by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations. Independent geometric representations,
as described below, should only be used when the
<i>IfcCurtainWall</i> is not defined as an aggregate. If defined
as an aggregate, the geometric representation is the sum of the
representations of the components within the aggregate.</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcCurtainWall</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the same
<i>IfcSpatialStructureElement</i> that is used in the
<i>ContainedInStructure</i> inverse attribute or to a referenced
spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p>If the <i>IfcCurtainWall</i> establishes an aggregate, then
all contained elements (defined by the <i>IsDecomposedBy</i>
inverse attribute) shall be placed relative to the
<i>IfcCurtainWall.ObjectPlacement</i>.</p>
<p><b><i>Geometric Representation</i></b></p>
<p>The geometric representation of <i>IfcCurtainWall</i> is
defined using the following multiple shape representations for
its definition:</p>
<ul>
<li>Axis: A two-dimensional open curve (for restrictions see
below) defining the axis for the curtain wall.
<ul>
<li>This is an optional representation for curtain walls.</li>
</ul>
</li>
<li>Body: A surface model or boundary representation model
representation defining the 3D shape of the curtain wall.
<ul>
<li>If the <i>IfcCurtainWall</i> has components (referenced by
<i>SELF\IfcObject.IsDecomposedBy</i>) then no independent shape
representation with <i>RepresentationType</i> = 'Body' shall be
defined. The body of <i>IfcCurtainWall</i> is then geometrically
represented by the shape representation of its components. The
components are accessed via
<i>SELF\IfcObject.IsDecomposedBy[1].RelatedObjects</i>.</li>
</ul>
<ul>
<li>If the <i>IfcCurtainWall</i> has no components defined (empty
set of <i>SELF\IfcObject.IsDecomposedBy</i>) then the
<i>IfcCurtainWall</i> may be represented by an shape
representation with the <i>RepresentationIdentifier</i> =
'Body'.</li>
</ul>
</li>
</ul>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcCurtainWall</i> is
defined using the 'Axis' representation. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D'</li>
</ul>
<p>The following additional constraints apply to the 'Axis'
representation:</p>
<ul>
<li><i>Axis</i> : <i>IfcPolyline</i> having two <i>Points</i>, or
<i>IfcTrimmedCurve</i> with <i>BasisCurve</i> of Type
<i>IfcLine</i> or <i>IfcCircle</i>.</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body shape representation of <i>IfcCurtainWall</i> is
defined using the 'Body' representation. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel', 'Brep' and
'MappedRepresentation'</li>
</ul>
<p>An own 'Body' representation shall only be included if no
components of the curtain wall are defined.</p>
</EPM-HTML>"
1424;IfcRailing;"<EPM-HTML>
<p><u>Definition of IAI</u>: The railing is a frame assembly
adjacent to human circulation spaces and at some space boundaries
where it is used in lieu of walls or to compliment walls.
Designed to aid humans, either as an optional physical support,
or to prevent injury by falling.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New Entity in
IFC Release 2.0</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcRailing</i> defines the occuurence of any railing,
common information about railing types (or styles) is handled by
<i>IfcRailingType</i>. The <i>IfcRailingType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common material, common set of properties and common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcRailingType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcRailing</i> is defined by the
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p>Material information can also be given at the
<i>IfcRailingType</i>, defining the common attribute data for all
occurrences of the same type.˙It is then accessible by the
inverse <i>IsDefinedBy</i> relationship pointing to
<i>IfcRailingType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterial</i>. If both are given, then the material directly
assigned to <i>IfcRailing</i> overrides the material assigned to
<i>IfcRailingType</i>.</p>
<p><u><b>Property Set Use Definition</b></u></p>
<p>The property sets relating to the <i>IfcRailing</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcRailing</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_RailingCommon.xml"" target=
""SOURCE"">Pset_RailingCommon</a>: common property set for all
railing occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcRailing</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.MethodOfMeasurement</i> = 'BaseQuantities'.
Other quantities can be defined being subjected to local standard
of measurement with another string value assigned to
<i>MethodOfMeasurement</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_RailingBaseQuantities.xml""
target=""SOURCE"">Qto_RailingBaseQuantities</a>: base quantities
for all railing occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcRailing</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcRailing</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcRailing</i> may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcStair</i>, or <i>IfcRamp</i> as a special focus subtypes.
In this case it should not be additionally contained in the
project spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcRailing</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. Included are:</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcRailing</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the same
<i>IfcSpatialStructureElement</i> that is used in the
<i>ContainedInStructure</i> inverse attribute or to a referenced
spatial structure element at a higher level</li>
<li>If the <i>IfcRailing</i>, however, is used by an
<i>IfcStair</i> or <i>IfcRamp</i>, and this container class
defines its own local placement, then the <i>PlacementRelTo</i>
relationship of <i>IfcLocalPlacement</i> shall point to the local
placement of <i>IfcStair</i> or <i>IfcRamp</i>.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the <font color=""#0000FF"">'Axis'</font>, 'Body',
and 'Box' representations are supported. The 'Box' representation
includes the representation type 'BoundingBox' and is explained
at <i>IfcBuildingElement</i>.</p>
<p><b>Axis Representation</b></p>
<p>The axis geometric representation of <i>IfcRailing</i> is
defined using the 'Axis' representation. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', 'Curve3D'</li>
</ul>
<p><b>Body Representation</b></p>
<p>Currently the use of 'SurfaceModel', 'Brep' and
'MappedRepresentation' representations of <i>IfcRailing</i> are
supported. The conventions to use these representations are given
at the level of the supertype, <i>IfcBuildingElement</i>. No
further constraints or provisions on how to use the
representation types are defined for <i>IfcRailing</i>.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel', 'Brep',
'MappedRepresentation'</li>
</ul>

</EPM-HTML>"
1434;IfcDoor;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: Construction for
closing an opening, intended primarily for access with hinged,
pivoted or sliding operation.</p>
<p>The door is a building element
that is predominately used to provide controlled access for
people and goods. It includes constructions with hinged, pivoted,
sliding, and additionally revolving and folding operations. A
door consists of a lining and one or several panels.</p>
<p>The <i>IfcDoor</i> defines a particular occurrence of a door
inserted in the spatial context of a project. A door can:</p>
<ul>
<li>be inserted as a filler in an opening using the
<i>IfcRelFillsElement</i> relationship, then the <i>IfcDoor</i>
has an inverse attribute <i>FillsVoids</i> provided,
<ul>
<li style=""list-style: none""><small>NOTE˙ View definitions or
implementer agreements may restrict the relationship to only
include one window (or door) into one opening.</small><br>
<br></li>
</ul>
</li>
<li>be part of an element assembly, in general an
<i>IfcCurtainWall</i>, using the <i>IfcRelAggregates</i>
relationship, then the inverse attribute <i>Decomposes</i> is
provided.</li>
<li>or be a ""free standing"" door, then the <i>IfcDoor</i> has no
inverse attributes <i>FillsVoids</i> or <i>Decomposes</i>
provided.</li>
</ul>
<p>The IFC specification provides two entities for door
occurrences:</p>
<ul>
<li><i>IfcDoorStandardCase</i> used for all occurrences of doors,
that have a 'Profile' shape representation defined to which a set
of shape parameters for lining and framing properties apply.
Additionally it requires the provision of an <i>IfcDoorType</i>
that references one <i>IfcDoorLiningProperties</i> and on to many
<i>IfcDoorPanelProperties</i>.
<ul>
<li style=""list-style: none""><small>NOTE˙ see
<i>IfcDoorStandardCase</i> for all specific constraints imposed
by this subtype.</small></li>
</ul>
</li>
<li><i>IfcDoor</i> used for all other occurrences of doors,
particularly for doors having only 'Brep', or 'SurfaceModel'
geometry without applying shape parameters.</li>
</ul>
<p>The actual parameter of the door and/or its shape are defined
by the <i>IfcDoor</i> as the occurrence definition (or project
instance), or by the <i><font color=
""#0000FF"">IfcDoorType</font></i> as the specific definition (or
project type). The following parameters are given:</p>
<ul>
<li>at the <i>IfcDoor</i> or <i>IfcDoorStandardCase</i> for
occurrence specific parameters. The <i>IfcDoor</i>
specifies:</li>
<li style=""list-style: none"">
<ul>
<li>the door width and height</li>
<li>the door opening direction (by the y-axis of the
<i>ObjectPlacement</i>)<br>
<br></li>
</ul>
</li>
<li>at the <i><font color=""#0000FF"">IfcDoorType</font></i>, to
which the <i>IfcDoor</i> is related by the inverse relationship
<i>IsDefinedBy</i> pointing to <i>IfcRelDefinesByType</i>, for
type parameters common to all occurrences of the same type.</li>
<li style=""list-style: none"">
<ul>
<li>the operation type (single swing, double swing, revolving,
etc.)</li>
<li>the door hinge side (by using two different styles for right
and left opening doors)</li>
<li>the construction material type</li>
<li>the particular attributes for the lining by the
<i>IfcDoorLiningPr</i>operties</li>
<li>the particular attributes for the panels by the˙
<i>IfcDoorPanelProperties</i><br></li>
</ul>
</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE The attributes <i>PredefinedType</i> and <i>OperationType</i> are added, the applicable type object has been changed to <i>IfcDoorType</i>.</blockquote>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcDoor</i> is defined by the
<i>IfcMaterialConstituentSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p>The following keywords for
<i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i>
shall be used:</p>
<ul>
<li>'Lining' - to indicate that the material constituent applies
to to the door lining</li>
<li>'Framing' - to indicate that the material constituent applies
to to the door panel(s), if not provided, the 'Lining' material
information applied to panel(s) as well</li>
<li>'Glazing' - to indicate that the material constituent applies
to to the glazing part</li>
</ul>
<p>If the fall back single <i>IfcMaterial</i> is referenced, it
applies to the lining and framing of the door.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcDoor</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcDoor</i> are part
of this IFC release:</p>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_DoorCommon.xml""
target=""SOURCE"">Pset_DoorCommon</a>: common property set for all
door occurrences</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowGlazingType.xml""
target=""SOURCE"">Pset_DoorWindowGlazingType</a>: specific property
set for the glazing properties of the door glazing, if
available</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowShadingType.xml""
target=""SOURCE"">Pset_DoorWindowShadingType</a>: specific property
set for the shading properties of the door glazing, if
available</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcDoor</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to
<i>MethodOfMeasurement</i>. Quanties shall be never assigned to
the <i>IfcDoorType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_DoorBaseQuantities.xml""
target=""SOURCE"">Qto_DoorBaseQuantities</a>: base quantities for
all door occurrences.</li>
</ul>

<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcDoor</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships as shown in Figure 96. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcDoor</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcDoor</i> may be aggregated into an element assembly
using the objectified relationship <i>IfcRelAggregates</i>,
refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Doors may be part of
an <i>IfcCurtainWall</i> as a special focus subtype. In this case
it should not be additionally contained in the project spatial
hierarchy, i.e.˙<i>SELF\IfcElement.ContainedInStructure</i>
should be <i>NIL.</i></li>
</ul>

<small>NOTE The containment shall be defined independently of the
filling relationship, that is, even if the <i>IfcDoor</i> is a
filling of an opening established by <i>IfcRelFillsElement</i>,
it is also contained in the spatial structure by an
<i>IfcRelContainedInSpatialStructure</i>.</small></blockquote>

<table>
<tr><td><img src=""figures/IfcDoor_Containment-01.png"" alt=
""Containment"" width=""600"" height=""550"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 96 &mdash; Door containment</p></td></tr>
</table>

<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcDoor</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations. The <i>IfcDoor</i>, in case of an occurrance
object, gets its parameter and shape from the <i>IfcDoorType</i>.
If an <i>IfcRepresentationMap</i> (a block definition) is defined
for the <i>IfcDoorType</i>, then the <i>IfcDoor</i> inserts it
through the <i>IfcMappedItem</i>.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcDoor</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ol>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement of
the same element (if given), in which the <i>IfcDoor</i> is used
as a filling (normally an <i>IfcOpeningElement</i>), as provided
by the <i>IfcRelFillsElement</i> relationship.</li>
<li>If the <i>IfcDoor</i> is not inserted into an
<i>IfcOpeningElement</i>, then the <i>PlacementRelTo</i>
relationship of <i>IfcLocalPlacement</i> shall point (if given)
to the local placement of the same
<i>IfcSpatialStructureElement</i> that is used in the
<i>ContainedInStructure</i> inverse attribute or to a referenced
spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ol>
<p><b><i>Geometric Representation</i></b></p>
<p>The˙geometric representation of <i>IfcDoor</i> is defined
using the following (potentially˙multiple)
<i>IfcShapeRepresentation</i>'s for its
<i>IfcProductDefinitionShape</i>:</p>
<ul>
<li><u>Profile</u>: A˙<font color=""#0000FF"">'Curve3D'</font>
consisting of a single losed curve defining the outer boundary of
the door (lining). The door parametric representation uses this
profile in order to apply the door lining and panel parameter. If
not provided, the profile of the <i>IfcOpeningElement</i> is
taken.</li>
<li><u>FootPrint</u>: A 'GeometricCurveSet', or 'Annotation2D'
representation defining the 2D shape of the door</li>
<li><u>Body</u>: A 'SweptSolid', 'SurfaceModel', or 'Brep'
representation defining the 3D shape of the door.</li>
</ul>
<p>In addition the parametric representation of a (limited) door
shape is available by applying the parameters from
<i>IfcDoorType</i> referencing <i>IfcDoorLiningProperties</i> and
<i>IfcDoorPanelProperties</i>. The purpose of the parameter is
described at those entities and below (door opening operation by
door type).</p>
<p><b>Profile -˙'Curve3D' representation</b></p>
<p>The door profile is represented by a three-dimensional closed
curve within a particular shape representation. The profile is
used to apply the parameter of the parametric door
representation.˙The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Profile'</li>
<li><i>RepresentationType</i> : 'Curve3D', only a single closed
curve shall be contained in the set of
<i>IfcShapeRepresentation.Items</i>.</li>
</ul>
<p>A 'Profile' representation has to be provided if:</p>
<ul>
<li>a parametric representation shall be applied to the door
AND</li>
<li style=""list-style: none"">
<ul>
<li>the˙door is 'free standing', or</li>
<li>the opening into which the˙door is inserted is not extruded
horizontally (i.e. where the opening profile does not match
the˙door profile)</li>
</ul>
</li>
</ul>
<p><b>FootPrint -˙'GeometricCurveSet' or 'Annotation2D'
representation</b></p>
<p>The door foot print is represented by a set of
two-dimensional˙curves (or in case of 'Annotation2D' additional
hatching and text) within a particular shape representation. The
foot print is used for the planview representation of the
door.˙The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet', or
'Annotation2D'</li>
</ul>
<p><b>Body - 'SweptSolid', 'SurfaceModel', or 'Brep'
representation</b></p>
<p>The door body is either represented parameterically (see
parametric representation) or by explicit 3D shape. The 3D shape
is given by using extrusion geometry, or surface models, or Brep
models within a particular shape representation. The body is used
for the model view representation of the door.˙The following
attribute values for the <i>IfcShapeRepresentation</i> holding
this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid', 'SurfaceModel', or
'Brep'</li>
</ul>
<p><b>MappedRepresentation</b></p>
<p>The 'FootPrint' and 'Body' geometric representation of
<i>IfcDoor</i> can be shared among several identical doors using
the 'MappedRepresentation'. The following attribute values for
the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint', 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for the˙ 'FootPrint', 'Body'
representation identifiers, shall apply to the
<i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
<p><u><b>Parameteric Representation using parameters at
<i>IfcDoorType</i></b></u></p>
<p>The parameters that defines the shape of the <i>IfcDoor</i>,
are given at the <i>IfcDoorType</i> and the property sets, which
are included in the <i>IfcDoorType</i>. The <i>IfcDoor</i> only
defines the local placement which determines the opening
direction of the door. <font color=""#0000FF"">The overall size of
the <i>IfcDoor</i> to be used to apply the lining or panel
parameter provided by the <i>IfcDoorType</i> is determined by the
IfcShapeRepresentation with the RepresentationIdentifier =
'Profile'. Only in case of an <i>IfcDoor</i> inserted into an
<i>IfcOpeningElement</i> using the <i>IfcRelFillsElement</i>
relatioship, having a horizontal extrusion (along the y-axis of
the <i>IfcDoor</i>), the overall size is determined by the
extrusion profile of the <i>IfcOpeningElement</i>.</font></p>
<blockquote><small>NOTE ˙The <i>OverallWidth</i> and
<i>OverallHeight</i> parameters are for informational purpose
only.</small></blockquote>
<p>The opening direction is determined by the local placement of
<i>IfcDoor</i> and the <i>OperationType</i> of the door
style as shown in Figure 97.</p>
<blockquote><small>NOTE ˙There are different definitions in
various countries on what a left opening or left hung or left
swing door is (same for right). Therefore the IFC definition may
derivate from the local standard and need to be mapped
appropriately.</small></blockquote>

<table><tr><td>

<table border=""1"" cellpadding=""2"" cellspacing=""2"">
<thead>
<tr>
<td align=""left"" valign=""top""><small><b>Opening
directions</b></small></td>
<td align=""left"" valign=""top"">
<small><b>Definitions</b></small></td>
<td align=""left"" valign=""top""><small><b>Reference to other
standards</b></small></td>
</tr>
</thead>
<tbody>
<tr valign=""top"">
<td><small><img alt=""fig 1"" src=""figures/IfcDoor-Fig01.gif""
height=""130"" width=""150""><br></small></td>
<td align=""left""><small>The door panel (for swinging doors) opens
always into the direction of the positive Y axis of the local
placement. The determination of whether the door opens to the
left or to the right is done at the level of the
<i>IfcDoorType</i>. Here it is a left side opening door given
by˙<i>IfcDoorType.OperationType</i> =
SingleSwingLeft</small></td>
<td align=""left""><small>refered to as LEFT HAND (LH) in US *<br>
<br>
refered to as DIN-R (right hung) in Germany</small></td>
</tr>
<tr valign=""top"">
<td><small><img alt=""fig 2"" src=""figures/IfcDoor-Fig02.gif""
height=""130"" width=""150""><br></small></td>
<td align=""left""><small>If the door should open to the other
side, then the local placement has to be changed. It is still a
left side opening door, given by <i>IfcDoorType.OperationType</i>
= SingleSwingLeft</small></td>
<td align=""left""><small>refered to as RIGHT HAND REVERSE (RHR) in
US *<br>
<br>
refered to as DIN-R (right hung) in Germany</small></td>
</tr>
<tr valign=""top"">
<td><img alt=""fig 3"" src=""figures/IfcDoor-Fig03.gif"" height=""130""
width=""150""></td>
<td align=""left""><small>If the door panel (for swinging doors)
opens to the right, a separate door style needs to be used (here
<i>IfcDoorTypee.OperationType</i> = SingleSwingRight) and it
always opens into the direction of the positive Y axis of the
local placement.˙</small></td>
<td align=""left""><small>refered to as RIGHT HAND (RH) in US *<br>
<br>
refered to as DIN-L (left hung) in Germany</small></td>
</tr>
<tr valign=""top"">
<td align=""left"" valign=""top""><small><img alt=""fig 4"" src=
""figures/IfcDoor-Fig04.gif"" height=""130"" width=
""150""><br></small></td>
<td align=""left""><small>If the door panel (for swinging doors)
opens to the right, and into the opposite directions, the local
placement of the door need to change. The door style is given by
<i>IfcDoorType.OperationType</i> = SingleSwingRight.</small></td>
<td align=""left""><small>refered to as LEFT HAND REVERSE (LHR) in
US *<br>
<br>
refered to as DIN-L (left hung) in Germany</small></td>
</tr>
</tbody>
<tfoot>
<tr valign=""top"">
<td align=""right"" colspan=""3""><small>* it assumes that the
'inside/private/primary' space is above (top in the pictures) and
the 'outside/public/secondary' space is below (bottom in the
pictures).</small></td>
</tr>
</tfoot>
</table>

</td></tr>
<tr><td><p class=""figure"">Figure 97 &mdash; Door swing</p></td></tr>
</table>


</EPM-HTML>"
1441;IfcDoorStandardCase;"<EPM-HTML>
<p>The standard door,
<i>IfcDoorStandardCase</i>, defines a door with certain constraints
for the provision of operation types, opening directions, frame and
lining parameters, and with certain constraints for the geometric
representation. The <i>IfcDoorStandardCase</i> handles all cases of
doors, that:</p>
<ul>
<li>are inserted into an opening, represented by
<i>IfcOpeningElement</i>, using the <i>IfcRelFillsElement</i>
relationship</li>
<li>have a local placement relative to this opening, and with the
y-axis of the placement pointing into the opening direction</li>
<li>have a profile geometry, represented by
<i>IfcShapeRepresentation.RepresentationIdentifier</i>=""Profile"" as
a closed curve to which the door parameter apply. The profile
represents a rectangle within the xz plane of the local
placement</li>
<li>have a reference to an <i>IfcDoorType</i> to define the opening
direction and the operation type (swinging, sliding, folding, etc.)
of the door. The attribute <i>OperationType</i> shall be provided
and not being UNDEFINED, and the attribute
<i>ParameterTakesPrecedence</i> shall be ""TRUE"".</li>
<li>have an <i>IfcDoorLiningProperties</i> and an
<i>IfcDoorPanelProperties</i> instances included in the set of
<i>HasPropertySets</i> at <i>IfcDoorType</i></li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC2x4.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcDoorStandardCase</i> defines the occuurence of any door,
common information about door types (or styles) is handled by
<i>IfcDoorType</i>. The <i>IfcDoorType</i> (that has to be present)
establishes the common type name, usage (opening direction and
operation), common set of properties, including shape parameters,
like lining thickness panel width, etc. and maybe an additional
common shape representations (using <i>IfcRepresentationMap</i>).
The <i>IfcDoorType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i> attribute.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcDoorStandardCase</i> are
defined at the supertype <i>IfcDoor</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcDoorStandardCase</i> are
defined at the supertype <i>IfcDoor</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcDoorStandardCase</i> are defined at the supertype
<i>IfcDoor</i>.</p>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcDoorStandardCase</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcDoor</i>.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>The geometric representation of <i>IfcDoorStandardCase</i> is
defined using the following multiple shape representations for its
definition:</p>
<ul>
<li><u>Profile</u>: a three-dimensional closed curve within a
particular shape representation. The profile is used to apply the
parameter of the parametric door representation. The profile around
the edges of the opening is used to apply the door lining and door
panel shape parameter.</li>
<li><u>MappedRepresentation</u>: A SweptSolid, SurfaceModel, or
Brep Representation or a CSG additionally defining the 3D shape of
the standard door in addition to the parametric representation by
applying the <i>IfcDoorLiningProperties</i> and an the
<i>IfcDoorPanelProperties</i> to the Profile representation.</li>
</ul>
<p><b>Profile representation</b></p>
<p>The door profile is represented by a three-dimensional closed
curve within a particular shape representation. The profile is used
to apply the parameter of the parametric door
representation.&nbsp;The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Profile'</li>
<li><i>RepresentationType</i> : 'Curve3D' or 'GeometricCurveSet',
in case of 'GeometricCurveSet' only a single closed curve shall be
contained in the set of <i>IfcShapeRepresentation.Items</i>.</li>
</ul>
<p>The following additional constraints apply to the 'Profile'
representation type:</p>
<ul>
<li><u>Curve</u>: being an <i>IfcPolyline</i> defining a
rectangle.</li>
<li><u>Position</u>: The curve shall lie in the xz plane of the
object placement coordinate (the y coordinate values of the
<i>IfcCartesianPoint</i>'s shall be 0.).</li>
</ul>

<p>Figure 98 illustrates applying the door lining parameters to the door profile shape representation.  The profile defines the outer boundary to which the door lining parameters relate as:</p>
<ul>
<li><i>IfcDoorLiningProperties.LiningDepth</i> starting at distance defined by <i>LiningOffset</i> going into the positive y direction.</li>
<li><i>IfcDoorLiningProperties.LiningThickness</i> offset into the inner side of the rectangle.</li>
<li><i>IfcDoorLiningProperties.LiningOffset</i> distance along the positive y direction to where the <i>LiningDepth</i> applies.</li>
<li><i>IfcDoorLiningProperties.ThresholdThickness</i> starting at the bottom edge of the rectangle into the inner side of the rectangle</li>
<li><i>IfcDoorLiningProperties.ThresholdDepth</i> starting at distance defined by <i>LiningOffset</i> going into the positive y direction.</li>
<li><i>IfcDoorLiningProperties.TransomOffset</i> starting at the bottom edge of the rectangle (along local x axis) into the inner side of the rectangle, distance provided as percentage of overall height. Distance to the centre line of the transom.</li>
</ul>

<table summary="""">
<tr valign=""top""><td><img src=""figures/IfcDoorStandardCase-01.png"" alt=""standard door"" border=""0""></td></tr>
<tr valign=""top""><td><p class=""figure"">Figure 98 &mdash; Door profile</p></td></tr>
</table>

</EPM-HTML>"
1469;IfcWindow;"<EPM-HTML> 
<p><u>Definition form ISO 6707-1:1989</u>: Construction for
closing a vertical or near vertical opening in a wall or pitched
roof that will admit light and may admit fresh air.</p>
<p>The window is a building element
that is predominately used to provide natural light and fresh
air. It includes vertical and horizontal opening (e.g. skylights
or light domes). It includes constructions with swinging,
pivoting, sliding, or revolving panels and fixed panels. A window
consists of a lining and one or several panels.</p>
<p>The <i>IfcWindow</i> defines a particular occurrence of a
window inserted in the spatial context of a project. A window
can:</p>
<ul>
<li>be inserted into an <i>IfcOpeningElement</i> using the
<i>IfcRelFillsElement</i> relationship, , then the <i>IfcDoor</i>
has an inverse attribute <i>FillsVoids</i> provided,
<ul>
<li style=""list-style: none""><small>NOTE˙ View definitions or
implementer agreements may restrict the relationship to only
include one window (or door) into one opening.</small><br>
<br></li>
</ul>
</li>
<li>be part of an element assembly, often an
<i>IfcCurtainWall</i>, using the <i>IfcRelAggregates</i>
relationship, then the inverse attribute <i>Decomposes</i> is
provided.</li>
<li>or be a ""free standing"" window, then the <i>IfcWindow</i> has
no inverse attributes <i>FillsVoids</i> or <i>Decomposes</i>
provided.</li>
</ul>
<p>The IFC specification provides two entities for window
occurrences:</p>
<ul>
<li><i>IfcWindowStandardCase</i> used for all occurrences of
windows, that have a 'Profile' shape representation defined to
which a set of shape parameters for lining and framing properties
apply. Additionally it requires the provision of an
<i>IfcWindowType</i> that references one
<i>IfcWindowLiningProperties</i> and on to many
<i>IfcWindowPanelProperties</i>.
<ul>
<li style=""list-style: none""><small>NOTE˙ see
<i>IfcWindowStandardCase</i> for all specific constraints imposed
by this subtype.</small></li>
</ul>
</li>
<li><i>IfcWindow</i> used for all other occurrences of windows,
particularly for windows having only 'Brep', or 'SurfaceModel'
geometry without applying shape parameters.</li>
</ul>
<p>The actual parameter of the window and/or its shape is defined
at the <i>IfcWindow</i> as the occurrence definition (or project
instance), or by the <i><font color=
""#0000FF"">IfcWindowType</font></i> as the specific definition (or
project type). The following parameters are given:</p>
<ul>
<li>at the <i>IfcWindow</i> or <i>IfcWindowStandardCase</i> for
occurrence specific parameters. The <i>IfcWindow</i>
specifies:</li>
<li style=""list-style: none"">
<ul>
<li>the window width and height</li>
<li>the window opening direction (by the y-axis of the
<i>ObjectPlacement</i>)<br>
<br></li>
</ul>
</li>
<li>at the <font color=""#0000FF""><i>IfcWindowType</i></font> to
which the <i>IfcWindow</i> is related by the inverse relationship
<i>IsDefinedBy</i> pointing to <i>IfcRelDefinesByType</i>, for
type parameters common to all occurrences of the same type.</li>
<li style=""list-style: none"">
<ul>
<li>the partitioning type (single panel, double panel, tripel
panel, more panels)</li>
<li>the operation type (swing, tilt and turn, pivot revolve,
fixed case ment, etc.)</li>
<li>the window panel hinge side (by using two different styles
for right and left opening windows)</li>
<li>the construction material type</li>
<li>the particular attributes for the lining by the
<i>IfcWindowLiningProperties</i></li>
<li>the particular attributes for the panels by the˙
<i>IfcWindowPanelProperties</i><br></li>
</ul>
</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE The attributes <i>PredefinedType</i> and <i>OperationType</i> are added, the applicable type object has been changed to <i>IfcDoorType</i>.</blockquote>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcWindow</i> is defined by the
<i>IfcMaterialConstituentSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p>The following keywords for
<i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i>
shall be used:</p>
<ul>
<li>'Lining' - to indicate that the material constituent applies
to to the window lining</li>
<li>'Framing' - to indicate that the material constituent applies
to to the window panel(s), if not provided, the 'Lining' material
information applied to panel(s) as well</li>
<li>'Glazing' - to indicate that the material constituent applies
to to the glazing part</li>
</ul>
<p>If the fall back single <i>IfcMaterial</i> is referenced, it
applies to the lining and framing of the window.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcWindow</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcWindow</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_WindowCommon.xml"" target=
""SOURCE"">Pset_WindowCommon</a>: common property set for all
window occurrences</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowGlazingType.xml""
target=""SOURCE"">Pset_DoorWindowGlazingType</a>: specific property
set for the glazing properties of the window glazing, if
available</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowShadingType.xml""
target=""SOURCE"">Pset_DoorWindowShadingType</a>: specific property
set for the shading properties of the window glazing, if
available</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcWindow</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to
<i>MethodOfMeasurement</i>. Quanties shall be never assigned to
the <i>IfcWindowStyle</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_WindowBaseQuantities.xml""
target=""SOURCE"">Qto_WindowBaseQuantities</a>: base quantities for
all window occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>

<p>The <i>IfcWindow</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the
aggregation within an˙element assembly.</p>
<ul>
<li>The <i>IfcWindow</i> is placed within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcWindow</i> may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Windows may be part
of an <i>IfcCurtainWall</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy,
i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>

<p>Figure 141 illustrates window containment.</p>
<blockquote class=""note"">NOTE The containment shall be defined independently of the filling relationship, that is, even if the <i>IfcWindow</i> is a filling of an opening established by <i>IfcRelFillsElement</i>, it is also contained in the spatial structure by an <i>IfcRelContainedInSpatialStructure</i>.</blockquote>

<table>
<tr><td><img src=""figures/IfcWindow_Containment-01.png"" alt=
""Containment"" width=""600"" height=""550"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 141 &mdash; Window containment</p></td></tr>
</table>

<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcWindow</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representation. The <i>IfcWindow</i>, in case of an occurrence
object, gets its parameter and shape from the
<i>IfcWindowType</i>. If an <i>IfcRepresentationMap</i> (a block
definition) is defined for the <i>IfcWindowType</i>, then the
<i>IfcWindow</i> inserts it through the <i>IfcMappedItem</i>
(refered to by <i>IfcShapeRepresentation.Items</i>).</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcWindow</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ol>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement of
the same element (if given), in which the <i>IfcWindow</i> is
used as a filling (normally an <i>IfcOpeningElement</i>), as
provided by the <i>IfcRelFillsElement</i> relationship.</li>
<li>If the <i>IfcWindow</i> is not inserted into an
<i>IfcOpeningElement</i>, then the <i>PlacementRelTo</i>
relationship of <i>IfcLocalPlacement</i> shall point (if given)
to the local placement of the same
<i>IfcSpatialStructureElement</i> that is used in the
<i>ContainedInStructure</i> inverse attribute or to a referenced
spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ol>
<p><b><i>Geometric Representation</i></b></p>
<p>The˙geometric representation of <i>IfcWindow</i> is defined
using the following (potentially˙multiple)
<i>IfcShapeRepresentation</i>'s for its
<i>IfcProductDefinitionShape</i>:</p>
<ul>
<li><u>Profile</u>: A˙<font color=""#0000FF"">'Curve3D'</font>
consisting of a single losed curve defining the outer boundary of
the window (lining). The˙window parametric representation uses
this profile in order to apply the˙window lining and panel
parameter. If not provided, the profile of the
<i>IfcOpeningElement</i> is taken.</li>
<li><u>FootPrint</u>: A 'GeometricCurveSet', or 'Annotation2D'
representation defining the 2D shape of the˙window</li>
<li><u>Body</u>: A 'SweptSolid', 'SurfaceModel', or 'Brep'
representation defining the 3D shape of the˙window.</li>
</ul>
<p>In addition the parametric representation of a
(limited)˙window shape is available by applying the parameters
from˙<i>IfcWindowType</i>
referencing˙<i>IfcWindowLiningProperties</i>
and˙<i>IfcWindowPanelProperties</i>. The purpose of the parameter
is described at those entities and below (parametric
representation).</p>
<p><b>Profile -˙'Curve3D' representation</b></p>
<p>The˙window profile is represented by a three-dimensional
closed curve within a particular shape representation. The
profile is used to apply the parameter of the parametric˙window
representation.˙The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Profile'</li>
<li><i>RepresentationType</i> : 'Curve3D', only a single closed
curve shall be contained in the set of
<i>IfcShapeRepresentation.Items</i>.</li>
</ul>
<p>A 'Profile' representation has to be provided if:</p>
<ul>
<li>a parametric representation shall be applied to the
window˙AND</li>
<li style=""list-style: none"">
<ul>
<li>the window is 'free standing', or</li>
<li>the opening into which the window is inserted is not extruded
horizontally (i.e. where the opening profile does not match the
window profile)</li>
</ul>
</li>
</ul>
<p><b>FootPrint -˙'GeometricCurveSet' or 'Annotation2D'
representation</b></p>
<p>The˙window foot print is represented by a set of
two-dimensional˙curves (or in case of 'Annotation2D' additional
hatching and text) within a particular shape representation. The
foot print is used for the plan view representation of
the˙window.˙The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet', or
'Annotation2D'</li>
</ul>
<p><b>Body - 'SweptSolid', 'SurfaceModel', or 'Brep'
representation</b></p>
<p>The˙window body is either represented parameterically (see
parametric representation) or by explicit 3D shape. The 3D shape
is given by using extrusion geometry, or surface models, or Brep
models within a particular shape representation. The body is used
for the model view representation of the˙window.˙The following
attribute values for the <i>IfcShapeRepresentation</i> holding
this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid', 'SurfaceModel', or
'Brep'</li>
</ul>
<p><b>MappedRepresentation</b></p>
<p>The 'FootPrint' and 'Body' geometric representation
of˙<i>IfcWindow</i> can be shared among several identical˙windows
using the 'MappedRepresentation'. The following attribute values
for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint', 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for the˙ 'FootPrint', 'Body'
representation identifiers, shall apply to the
<i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
<p><b><u>Parameteric Representation using parameters at
<i>IfcWindowType</i></u></b></p>
<p>The parameters, which define the shape of the
<i>IfcWindow</i>, are given at the <i>IfcWindowType</i> and the
property sets, which are included in the <i>IfcWindowType</i>.
The <i>IfcWindow</i> only defines the local placement.
<font color=""#0000FF"">The overall size of the <i>IfcWindow</i> to
be used to apply the lining or panel parameter provided by the
<i>IfcWindowType</i> is determined by the IfcShapeRepresentation
with the RepresentationIdentifier = 'Profile'. Only in case of an
<i>IfcWindow</i> inserted into an <i>IfcOpeningElement</i> using
the <i>IfcRelFillsElement</i> relatioship, having a horizontal
extrusion (along the y-axis of the <i>IfcDoor</i>), the overall
size is determined by the extrusion profile of the
<i>IfcOpeningElement</i>.</font></p>

<p>Figure 142 illustrates the insertion of a window into the <i>IfcOpeningElement</i> by creating an instance of
<i>IfcWindow</i> with <i>PartitioningType = DoublePanelHorizontal</i>. The parameters <i>OverallHeight</i> and <i>OverallWidth</i> show the extent of the window in the positive Z and X axis of the local placement of the window. The lining and the transom are created by the given parameters.</p>

<table>
<tr><td><img src=""figures/IfcWindow-Layout1.gif"" alt=""window 1"" border=""0"" height=""299"" width=""356""></td></tr>
<tr><td><p class=""figure"">Figure 142 &mdash; Window placement</p></td></tr>
</table>

<p>Figure 143 illustrates the final window (DoublePanelHorizontal) with first panel having <i>PanelPosition = TOP</i>, <i>OperationType = BOTTOMHUNG</i> and second panel having <i>PanelPosition = BOTTOM</i> and <i>OperationType = TILTANDTURNLEFTHAND</i>.</p>

<table>
<tr><td><img src=""figures/IfcWindow-Layout2.gif"" alt=""window 2"" border=""0"" height=""299"" width=""356""></td></tr>
<tr><td><p class=""figure"">Figure 143 &mdash; Window planes</p></td></tr>
</table>

<p><u><b>Window opening operation by window type</b></u></p>
<p>The parameters that defines the shape of the <i>IfcWindow</i>,
are given at the <i>IfcWindowType</i> and the property sets,
which are included in the <i>IfcWindowType</i>. The
<i>IfcWindow</i> only defines the local placement which
determines the opening direction of the window. The overall
layout of the <i>IfcWindow</i> is determined by
its˙<i>IfcWindowType.PartitioningType</i>. Each window panel has
its own operation type, provided by
<i>IfcWindowPanelProperties.OperationType</i>. All window panels
are assumed to open into the same direction (if relevant for the
particular window panel operation. The hindge side (whether a
window opens to the left or to the right) is determined by the
<i>IfcWindowPanelProperties</i><i>.OperationType</i>.</p>
<blockquote class=""note"">NOTE ˙There are different conventions in
different countries on how to show the symbolic presentation of
the window panel operation (the ""triangles""). Either as seen from
the exterior, or from the interior side. The following figures
show the symbolics from the exterior side (the convention as used
predominately in Europe).</blockquote>

<p>Figure 144 illustrates window operation types.</p>

<table><tr><td>

<table border=""1"" cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top"">
<td align=""left"" valign=""top""><small><img alt=""fig 1"" src=
""figures/IfcWindow-Fig01.gif"" height=""121"" width=
""301""><br></small></td>
<td align=""left"" valign=""top"">
<p><small>The window panel (for side hung windows) opens always
into the direction of the positive Y axis of the local placement.
The determination of whether the window opens to the left or to
the right is done at
<i>IfcWindowPanelProperties.OperationType</i>. Here it is a left
side opening window given by˙<i>OperationType</i> =
SideHungLeftHand.</small></p>
</td>
</tr>
<tr>
<td><small><img alt=""fig 2"" src=""figures/IfcWindow-Fig02.gif""
height=""121"" width=""301""><br></small></td>
<td valign=""top"">
<p><small>If the window should open to the other side, then the
local placement has to be changed. It is still a left hung
window, given by <i>IfcWindowPanelProperties.OperationType</i>
=˙SideHungLeftHand.</small></p>
</td>
</tr>
<tr>
<td><img alt=""fig 3"" src=""figures/IfcWindow-Fig03.gif"" height=
""121"" width=""301""></td>
<td valign=""top"">
<p><small>If the window panel (for side hung windows) opens to
the right, a separate window panel style needs to be used (here
<i>IfcWindowPanelProperties.OperationType</i>
=˙SideHungRightHand) and it always opens into the direction of
the positive Y axis of the local placement.˙</small></p>
</td>
</tr>
<tr valign=""top"">
<td align=""left"" valign=""top""><small><img alt=""fig 4"" src=
""figures/IfcWindow-Fig04.gif"" height=""121"" width=
""301""><br></small></td>
<td align=""left"" valign=""top"">
<p><small>If the window should open to the other side, then the
local placement has to be changed. It is still a right hung
window, given by <i>IfcWindowPanelProperties.OperationType</i>
=˙</small><small>SideHungRightHand.</small></p>
<small>.</small></td>
</tr>
</tbody>
</table>

</td></tr>
<tr><td><p class=""figure"">Figure 144 &mdash; Window operations</p></td></tr>
</table>

</EPM-HTML>"
1476;IfcWindowStandardCase;"<EPM-HTML>
<p>The standard window,
<i>IfcWindowStandardCase</i>, defines a window with certain
constraints for the provision of operation types, opening
directions, frame and lining parameters, construction types and
with certain constraints for the geometric representation. The
<i>IfcWindowStandardCase</i> handles all cases of windows,
that:</p>
<ul>
<li>are inserted into an opening, represented by
<i>IfcOpeningElement</i>, using the <i>IfcRelFillsElement</i>
relationship</li>
<li>have a local placement relative to this opening, and with the
y-axis of the placement pointing into the opening direction</li>
<li>have a profile geometry, represented by
<i>IfcShapeRepresentation.RepresentationIdentifier</i>=""Profile""
as a closed curve to which the window parameter apply. The
profile represents a rectangle within the xz plane of the local
placement</li>
<li>have a reference to an <i>IfcWindowType</i> to define the
opening direction and the operation type (swinging, sliding,
folding, etc.) of the window. The attribute <i>OperationType</i>
shall be provided and not being UNDEFINED, and the attribute
<i>ParameterTakesPrecedence</i> shall be ""TRUE"".</li>
<li>have a single <i>IfcWindowLiningProperties</i> and a set of
<i>IfcWindowPanelProperties</i> instances included in the set of
<i>HasPropertySets</i> at <i>IfcWindowType</i></li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC2x4.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcWindowStandardCase</i> defines the occuurence of any
window, common information about window types (or styles) is
handled by <i>IfcWindowType</i>. The <i>IfcWindowType</i> (that
has to be present) establishes the common type name, usage
(opening direction, configuration and operation), common set of
properties, including shape parameters, like lining thickness
panel width, etc. and maybe an additional common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcWindowType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcWindowStandardCase</i>
are defined at the supertype <i>IfcWindow</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcWindowStandardCase</i>
are defined at the supertype <i>IfcWindow</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcWindowStandardCase</i> are defined at the supertype
<i>IfcWindow</i>.</p>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcWindowStandardCase</i>
is given by the <i>IfcProductDefinitionShape</i>, allowing
multiple geometric representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcWindow</i>.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>The geometric representation of <i>IfcWindowStandardCase</i>
is defined using the following multiple shape representations for
its definition:</p>
<ul>
<li><u>Profile</u>: a three-dimensional closed curve within a
particular shape representation. The profile is used to apply the
parameter of the parametric window representation. The profile
around the edges of the opening is used to apply the window
lining and window panel shape parameter.</li>
<li><u>MappedRepresentation</u>: A SweptSolid, SurfaceModel, or
Brep Representation or a CSG additionally defining the 3D shape
of the standard window in addition to the parametric
representation by applying the <i>IfcWindowLiningProperties</i>
and an the <i>IfcWindowPanelProperties</i> to the Profile
representation.</li>
</ul>
<ul>
<li><i>RepresentationIdentifier</i> : 'Profile'</li>
<li><i>RepresentationType</i> : 'Curve3D' or 'GeometricCurveSet',
in case of 'GeometricCurveSet' only a single closed curve shall
be contained in the set of
<i>IfcShapeRepresentation.Items</i>.</li>
</ul>
<p>The following additional constraints apply to the 'Profile'
representation type:</p>
<ul>
<li><u>Curve</u>: being an <i>IfcPolyline</i> defining a
rectangle.</li>
<li><u>Position</u>: The curve shall lie in the xz plane of the
object placement coordinate (the y coordinate values of the
<i>IfcCartesianPoint</i>'s shall be 0.).</li>
</ul>
<p>As shown in Figure 145, the profile defines the outer boundary to which the window
lining parameters relate as:</p>
<ul>
<li><i>IfcWindowLiningProperties.LiningDepth</i> starting at
distance defined by <i>LiningOffset</i> going into the positive y
direction.</li>
<li><i>IfcWindowLiningProperties.LiningThickness</i> offset into
the inner side of the rectangle.</li>
<li><i>IfcWindowLiningProperties.LiningOffset</i> distance along
the positive y direction to where the <i>LiningDepth</i>
applies.</li>
<li><i>IfcWindowLiningProperties.FirstTransomOffset</i> starting
at the bottom edge of the rectangle (along local x axis) into the
inner side of the rectangle, distance provided as percentage of
overall height. Distance to the centre line of the transom.
<i>SecondTransomOffset</i> defined accordingly.</li>
<li><i>IfcWindowLiningProperties.FirstMullionOffset</i> starting
at the left edge of the rectangle (along local z-axis) into the
inner side of the rectangle, distance provided as percentage of
overall width. Distance to the centre line of the mullion.
<i>SecondMullionOffset</i> defined accordingly.</li>
</ul>

<table>
<tr><td><img src=""figures/IfcWindowStandardCase-01.png"" alt=
""standard window"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 145 &mdash; Window profile</p></td></tr>
</table>

</EPM-HTML>"
1495;IfcPlate;"<EPM-HTML>
<p><u>Definition from IAI</u>: An <i>IfcPlate</i> is a planar and
often flat part with constant thickness. A plate can be a
structural part carrying loads between or beyond points of
support, however it is not required to be load bearing.˙The
location of the plate (being horizontal, vertical or sloped) is
not relevant to its definition (in contrary to <i>IfcWall</i> and
<i>IfcSlab</i> (as floor slab)).˙</p>
<blockquote><small>NOTE ˙Plates are˙normally made of steel, other
metallic material, or by glass panels. However the definition of
<i>IfcPlate</i> is material independent and specific material
information shall be handled by using
<i>IfcAssociatesMaterial</i> to assign a material specification
to the <i>IfcPlate</i>.˙</small><br>
<br>
<small>NOTE ˙Although not necessarily, plates are often add-on
parts. This is represented by the <i>IfcRelAggregates</i>
decomposition mechanism used to aggregate parts, such as
<i>IfcPlate</i>, into a container element, e.g.
<i>IfcElementAssembly</i>, or <i>IfcCurtainWall</i>.˙</small><br>
<br>
<small>NOTE The representation of a plate in a structural
analysis model is provided by <i>IfcStructuralSurfaceMember</i>
being part of an
<i>IfcStructuralAnalysisModel</i>.</small></blockquote>
<p>An instance <i>IfcPlate</i> should preferably get its
geometric representation and material assignment through the type
definition by <i>IfcPlateType</i> assigned using the
<i>IfcRelDefinesByType</i> relationship. This allows identical
plates in a construction to be represented by the same instance
of <i>IfcPlateType</i>.</p>
<p>A plate may have openings, such as voids or recesses. They are
defined by an <i>IfcOpeningElement</i> attached to the plate
using the inverse relationship <i>HasOpenings</i> pointing to
<i>IfcRelVoidsElement</i>. The position number of a plate as
often used in steel construction is assigned through the
attribute <i>IfcElement.Tag</i></p>
<p>The IFC specification provides two entities for plate
occurrences:</p>
<ul>
<li><i>IfcPlateStandardCase</i> used for all occurrences of
plates, that are prismatic and where the thickness parameter can
be fully described by the <i>IfcMaterialLayerSetUsage</i>. These
plates are always represented geometrically by a 'SweptSolid'
geometry (or by a 'Clipping' geometry based on 'SweptSolid'), if
a 3D geometric representation is assigned. In addition they have
to have a corresponding <i>IfcMaterialLayerSetUsage</i>
assigned.</li>
<li><i>IfcPlate</i> used for all other occurrences of plates,
particularly for plates with changing thickness, or plates with
non planar surfaces, and plates having only 'SurfaceModel' or
'Brep' geometry.</li>
</ul>
<blockquote><font color=""#0000FF""><small>HISTORY New entity in
IFC Release 2x2</small></font></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p>The <i>IfcPlate</i> defines the occuurence of any plate,
common information about plate types (or styles) is handled by
<i>IfcPlateType</i>. The <i>IfcPlateType</i> (if present) may
establish the common˙type name, usage (or predefined) type,
common set of properties, common material layer set, and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcPlateType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcPlateType</i> is attached˙(i.e. if only occurrence
information is given) the <i>PredefinedType</i> should be
provided. If set to .USERDEFINED. a user defined value can be
provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcPlate</i> is defined by
<i>IfcMaterialLayerSet</i>, or <i>IfcMaterial</i> and attached by
the <i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It
is accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<blockquote><small>NOTE It is illegal to assign an
<i>IfcMaterialLayerSetUsage</i> to an <i>IfcPlate</i>. Only the
subtype <i>IfcPlateStandardCase</i> supports this
concept.</small></blockquote>
<p>Material information can also be given at the
<i>IfcPlateType</i>, defining the common attribute data for all
occurrences of the same type.˙It is then accessible by the
inverse <i><font color=""#0000FF"">IsTypedBy</font></i>
relationship pointing to <i>IfcPlateType.HasAssociations</i> and
via <i>IfcRelAssociatesMaterial.RelatingMaterial</i>.</p>
<p><u><b>Property Set Use Definition</b></u></p>
<p>The property sets relating to the <i>IfcPlate</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcPlate</i> are part
of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_PlateCommon.xml"" target=
""SOURCE"">Pset_PlateCommon</a>: common property set for all plate
occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcPlate</i> and
<i>IfcPlateStandardCase</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quanties shall
be never assigned to the <i>IfcPlateType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_PlateBaseQuantities.xml""
target=""SOURCE"">Qto_PlateBaseQuantities</a>: base quantities for
all plate occurrences.</li>
</ul>
<p><u><b>Containment Use Definitions</b></u></p>
<p>The <i>IfcPlate</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second relationship is the aggregation within
an˙element assembly.</p>
<ul>
<li>The˙<i>IfcPlate</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of˙<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The˙<i>IfcPlate</i> may be aggregated into an element
assembly using the objectified relationship
<i>IfcRelAggregates</i>, referring to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case, no additional relationship to the spatial hierarchy shall
be given (i.e.˙<i>SELF\IfcElement.ContainedInStructure</i> =
NIL), the relationship to the spatial container is handled by the
element assembly<i>.</i></li>
</ul>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>Ifc</i><i>Plate</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>Ifc</i><i>Plate</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to
a spatial structure element at a higher level, referenced by
that.
<ul>
<li>If the <i>IfcPlate</i> is part of an assembly, the
<i>PlacementRelTo</i> relationship of <i>IfcLocalPlacement</i>
shall point to the local placement of the container element, e.g.
<i>IfcElementAssembly</i>,</li>
</ul>
</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the <font color=""#0000FF"">'Surface'</font>,
<font color=""#0000FF"">'FootPrint'</font>, 'Body', and 'Box'
representations are supported. The 'Box' representation includes
the representation type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>Surface Representation</b></p>
<p>The surfacic geometric representation of <i>IfcPlate</i> is
defined using the 'Surface' representation.</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface3D'</li>
</ul>
<blockquote><small>NOTE The 'Surface' can be used to define a
surfacic model of the building (e.g. for analytical purposes, or
for reduced Level of Detail representation).</small></blockquote>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcPlate</i> can be represented
using the representation types 'SweptSolid', 'Clipping',
'MappedRepresentation', 'SurfaceModel', and 'Brep'. The
representation types 'SurfaceModel' and 'Brep' are explained at
<i>IfcBuildingElement</i>.</p>
<p><i>SweptSolid Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<blockquote><small>If a corresponding material definition using
<i>IfcMaterialLayerSetUsage</i> can be assigned, the subtype
<i>IfcPlateStandardCase</i> shall be used.</small></blockquote>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef,
IfcArbitraryProfileDefWithVoids, IfcRectangleProfileDef,
IfcCircleProfileDef, IfcEllipseProfileDef</i> shall be
supported.</li>
<li><u>Extrusion</u>: The profile can be extruded perpendicularly
or non-perpendicularly to the plane of the swept profile.</li>
</ul>
<p><i>Clipping Representation Type</i></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p><i>MappedRepresentation Representation Type</i></p>
<p>The 'MappedRepresentation' shall be supported as it allows for
reusing the geometry definition of the member type at all
occurrences of the same type. The following attribute values for
the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for the 'SweptSolid',
'Clipping', 'SurfaceModel', and 'Brep' geometric representation,
shall apply to the <i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
</EPM-HTML>
"
1500;IfcPlateStandardCase;"<EPM-HTML>
<p>The standard plate,
<i>IfcPlateStandardCase</i>, defines a plate with certain
constraints for the provision of material usage, parameters and
with certain constraints for the geometric representation. The
<i>IfcPlateStandardCase</i> handles all cases of plates, that:</p>
<ul>
<li>have a reference to the <i>IfcMaterialLayerSetUsage</i>
defining the material layers of the plate with thicknesses</li>
<li>are based on an extrusion of a planar surface as defined by the
plate profile</li>
<li>have a constant thickness along the extrusion direction</li>
<li>are consistent in using the correct material layer set offset
to the base planar surface in regard to the shape
representation</li>
<li>are extruded perpendicular to the plane surface</li>
</ul>
<p>The definitions of plate openings and niches are the same as
given at the supertype <i>IfcPlate</i>. The same agreements to the
special types of plates, as defined in the <i>PredefinedType</i>
attribute apply as well.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x Edition 4.</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p>The <i>IfcPlateStandardCase</i> defines the occuurence of any
plate, common information about plate types (or styles) is handled
by <i>IfcPlateType</i>. The <i>IfcPlateType</i> (if present) may
establish the common&nbsp;type name, usage (or predefined) type,
common set of properties, common material layer set, and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcPlateType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i> attribute.</p>
<p>The <i>IfcPlateStandardCase</i> defines in addition that the
<i>IfcPlateType</i> should have a unique
<i>IfcMaterialLayerSet</i>, that is referenced by
the&nbsp;<i>IfcMaterialLayerSetUsage</i> assigned to all
occurrences of this plate type.</p>

<p>Figure 107 illustrates assignment of <i>IfcMaterialLayerSetUsage</i> and <i>IfcMaterialLayerSet</i> to the <i>IfcPlateStandardCase</i> as the plate occurrence and to the <i>IfcPlateType</i>. The same <i>IfcMaterialLayerSet</i> shall be shared by many occurrences of <i>IfcMaterialLayerSetUsage</i>. This relationship shall be consistent to the relationship between the <i>IfcPlateType</i> and the <i>IfcPlateStandardCase</i>.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" >
<tr><td width=""610"" align=""left"" valign=""top"">
<p><img alt=""Material layer set and usage"" src=
""figures/IfcSlab_MaterialUsage-01.png"" height=""220"" width=
""501"">&nbsp;</p></td></tr>
<tr><td><p class=""figure"">Figure 107 &mdash; Plate type definition</p></td></tr>
</table>

<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcPlateStandardCase</i> is defined by
<i>IfcMaterialLayerSetUsage</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.
Multi-layer plates can be represented by refering to several
<i>IfcMaterialLayer</i>'s within the <i>IfcMaterialLayerSet</i>
that is referenced from the
<i>IfcMaterialLayerSetUsage</i>.&nbsp;</p>
<p>Material information can also be given at the
<i>IfcPlateType</i>, defining the common attribute data for all
occurrences of the same type.&nbsp;It is then accessible by the
inverse <i>IsDefinedBy</i> relationship pointing to
<i>IfcPlateType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i>. See <b>Type Use
Definition</b> for additional agreements for standard plates.</p>

<p>As shown in Figure 108, the following conventions shall be met:</p>
<ul>
<li>The reference coordinate system is the coordinate system established by the <i>IfcExtrudedAreaSolid.Position</i>.</li>
<li>The reference plane is the plane defined by the extruded profile of <i>IfcExtrudedAreaSolid.SweptSolid</i>. The <i>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</i> is given as a distance from this plane.</li>
<li>The <i>IfcMaterialLayerSetUsage.DirectionSense</i> defines how the <i>IfcMaterialLayer</i>'s are assigned to the reference plane. POSITIVE means in direction to the positive z-axis of the reference coordinate system.</li>
<li>The <i>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</i> is the distance parallel to the reference plane and always perpendicular to the base (XY) plane of the reference coordinate system. This is independent of a potential non-perpendicular extrusion given by <i>IfcExtrudedAreaSolid.ExtrudedDirection</i> &lt;&gt; 0.,0.,1. A positive value of <i>IfcMaterialLayerSetUsage.OffsetFromReferenceLine</i> would then point into the positive z-axis of the reference coordinate system.</li>
<li>The <i>Thickness</i> of each <i>IfcMaterialLayer</i> shall be the parallel distance (measured perpendicular to the base plane). The <i>TotalThickness</i> of the <i>IfcMaterialLayerSet</i> is the sum of all layer thicknesses and in case of a perpendicular extrusion identical with <i>IfcExtrudedAreaSolid.Depth</i></li>
<li>The <i>IfcMaterialLayerSetUsage.LayerSetDirection</i> i always AXIS3.</li>
</ul>

<table summary=""material use definition for standard plates"" border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top"" width=""610""><img src=""figures/IfcMaterialLayerSetUsage_Slab-01.png"" alt=""plate material layer set"" width=""601"" height=""321"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 108 &mdash; Plate material layers</p></td></tr>
</table>

<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcPlateStandardCase</i>
are defined at the supertype <i>IfcPlate</i>.</p>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcPlateStandardCase</i> are
defined at the supertype <i>IfcPlate</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcPlateStandardCase</i> are defined at the supertype
<i>IfcPlate</i>.</p>
<p><u><b>Geometry Use Definitions</b></u></p>
<p>The geometric representation of <i>IfcPlateStandardCase</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation. Included are:</p>
<p><b>Local Placement</b></p>
<p>The use of local placement is defined at the supertype
<i>IfcPlate</i>.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of 'SweptSolid' and 'Clipping'
representations is supported. In addition the general
representation type 'BoundingBox' is allowed. The geometry use
definitions for 'BoundingBox', is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>SweptSolid Representation</b></p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used for the 'SweptSolid' representation:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef,
IfcRectangleProfileDef, IfcRoundedRectangleProfileDef,
IfcCircleProfileDef, IfcEllipseProfileDef</i> shall be
supported.</li>
<li><u>Extrusion</u>: The profile can be extruded perpendicularly
or non-perpendicularly to the plane of the swept profile.</li>
<li><u>Material</u>: The definition of the
<i>IfcMaterialLayerSetUsage</i>, particularly of the
<i>OffsetFromReferenceLine</i> and the
<i>ForLayerSet.TotalThickness</i>, has to be consistent to the
'SweptSolid' representation.</li>
</ul>

<p>Figure 109 illustrates a 'SweptSolid' geometric representation.</p>
<blockquote class=""note"">NOTE The following interpretation of dimension parameter applies for polygonal plates (in ground floor view):</p>
<ul>
<li><i>IfcArbitraryClosedProfileDef.OuterCurve</i>: closed bounded curve interpreted as area (or foot print) of the plate.</li>
</ul>
</blockquote>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""420""><img src=""figures/IfcSlab_Standard-Layout1.gif"" alt=""standard plate"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 109 &mdash; Plate body extrusion</p></td></tr>
</table>

<p><b>Clipping representation</b></p>
<p>The 'Clipping' geometric representation of
<i>IfcSlabStandardCase</i> is defined using the swept area geometry
with additional clippings applied. The following attribute values
for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Clipping'</li>
</ul>
<p>The following constraints apply to the 'Clipping'
representation:</p>
<ul>
<li><u>Solid</u>: see 'SweptSolid' shape representation,</li>
<li><u>Profile</u>:&nbsp;see 'SweptSolid' shape
representation,</li>
<li><u>Extrusion</u>:&nbsp;see 'SweptSolid' shape
representation,</li>
<li><u>Material</u>:&nbsp;see 'SweptSolid' shape
representation,</li>
<li><u>Boolean result</u>: The <i>IfcBooleanClippingResult</i>
shall be supported, allowing for Boolean differences between the
swept solid (here <i>IfcExtrudedAreaSolid</i>) and one or several
<i>IfcHalfSpaceSolid</i>.</li>
</ul>

<p>Figure 110 illustrates a 'Clipping' geometric representation with definition of a plate using advanced geometric representation. The profile is extruded non-perpendicular and the plate body is clipped at the eave.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top"" width=""420""><img src=""figures/IfcSlab_Advanced-Layout1.gif"" alt=""advanced plate"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 110 &mdash; Plate body clipping</p></td></tr>
</table>

</EPM-HTML>"
1507;IfcChimney;"<EPM-HTML>
<p><u>Definition from ISO 6707-1:1989</u>: Construction
containing one or more flues. Flue: Duct designed to convey the
products of combustion to the open air. Chimney stack: Part of
the chimney that projects above a roof.</p>
<p><u>Definition from IAI</u>: Chimneys are typically vertical,
or as near as vertical, parts of the construction of a building
and part of the building fabric. Often constructed by pre-cast or
insitu concrete, today seldom by bricks.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcChimney</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcChimney</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_ChimneyCommon.xml"" target=
""SOURCE"">Pset_ChimneyCommon</a>: common property set for all
chimney occurrences.</li>
</ul>
<p>Property sets can also be given at the <i>IfcChimneyType</i>,
defining the common property data for all occurrences of the same
type.˙It is then accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcChimneyType.HasPropertySets</i>. If both are given, then
the properties directly assigned to <i>IfcChimney</i> overrides
the properties assigned to <i>IfcChimneyType</i>.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcChimney</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. It is accessible by the inverse
<i>IsDefinedBy</i> relationship. The following base quantities
are defined and should be exchanged with the
<i>IfcElementQuantity.MethodOfMeasurement</i> = 'BaseQuantities'.
Other quantities can be defined being subjected to local standard
of measurement with another string value assigned to <i>Name</i>
and a value provided for <i>MethodOfMeasurement</i>. Quanties
shall be never assigned to the <i>IfcChimneyType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_ChimneyBaseQuantities.xml""
target=""SOURCE"">Qto_ChimneyBaseQuantities</a>: base quantities
for all chimney occurrences.</li>
</ul>
</EPM-HTML>"
1514;IfcBuildingElementProxy;"<EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcBuildingElementProxy</i>
is a proxy definition that provides the same functionality as an
<i>IfcBuildingElement</i>, but without having a predefined meaning
of the special type of building element, it represents. Proxies can
also be used as spatial place holders or provisions, that maybe
later replaced by special types of elements.</p>
<p>One use of the proxy object is a provision for voids, i.e. where
a particular volume of space is requested by some engineering
function that might later be accepted or rejected and if accepted
potentially transformed into a void within a building element, like
a wall opening, or a slab opening. The provision for voids is
exchanged as an <i>IfcBuildingElementProxy</i> with the
<i>PredefinedType</i> = ProvisionForVoid.</p>
<p>Other usages of <i>IfcBuildingElementProxy</i> include:</p>
<ul>
<li>The <i>IfcBuildingElementProxy</i> can be used to exchange
special types of building elements for which the current IFC
Release does not yet provide a semantic definition.</li>
<li>The <i>IfcBuildingElementProxy</i> can also be used to
represent building elements for which the participating
applications can not provide additional semantic
classification.</li>
</ul>
<blockquote><font color=""#0000FF""><small>HISTORY&nbsp; New entity
in IFC Release 2x.</small></font><br>
<font color=""#FF0000""><small>IFC2x4 CHANGE&nbsp; The attribute
<i>CompositionType</i> has been replaced by <i>PredefinedType</i>,
being a superset of the enumerators.</small></font></blockquote>
<p><b><u>Type Use Definition</u></b></p>
<p>The <i>IfcBuildingElementProxy</i> defines the occuurence of any
building element, common information about the types (or styles) is
handled by <i>IfcBuildingElementProxyType</i>.</p>
<p>The <i>IfcBuildingElementProxyType</i> (if present) may
establish the common type name, usage (or predefined) type, common
material, common set of properties and common shape representations
(using <i>IfcRepresentationMap</i>). The
<i>IfcBuildingElementProxyType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <font color=
""#0000FF""><i>IsTypedBy</i></font> attribute.</p>
<blockquote>
<p><small>NOTE The <i>IfcBuildingElementProxyType</i> can be used
to share common information among many occurrences of the same
proxy without establishing a particular semantic meaning of the
type.</small></p>
</blockquote>
<p>If no <i>IfcBuildingElementProxyType</i> is attached (i.e. if
only occurrence information is given) the <i>PredefinedType</i>
should be provided. If set to .USERDEFINED. a user defined value
can be provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcBuildingElementProxy</i> is defined by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.</p>
<blockquote><small>Note It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcBuildingElementProxy</i> with the
<i>PredefinedType</i> = ProvisionForVoid.</small></blockquote>
<p>Material information can also be given at the
<i>IfcBuildingElementProxyType</i>, defining the common attribute
data for all occurrences of the same type.&nbsp;It is then
accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcBuildingElementProxyType.HasAssociations</i> and via
<i>IfcRelAssociatesMaterial.RelatingMaterial</i> to
<i>IfcMaterial</i>. If both are given, then the material directly
assigned to <i>IfcBuildingElementProxy</i> overrides the material
assigned to <i>IfcBuildingElementProxyType</i>.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcBuildingElementProxy</i>
are defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcBuildingElementProxy</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_BuildingElementProxyCommon.xml""
target=""SOURCE"">Pset_BuildingElementProxyCommon</a>: common
property set for all occurrences of building element proxies.</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_BuildingElementProxyProvisionForVoid.xml""
target=""SOURCE"">Pset_BuildingElementProxyProvisionForVoid</a>:
specific property set for all occurrences of building element proxy
with the PredefinedType: PROVISIONFORVOID.</li>
</ul>
<p>Property sets can also be given at the
<i>IfcBuildingElementProxyType</i>, defining the common property
data for all occurrences of the same type.&nbsp;It is then
accessible by the inverse <i><font color=
""#0000FF"">IsTypedBy</font></i> relationship pointing to
<i>IfcBuildingElementProxyType.HasPropertySets</i>. If both are
given, then the properties directly assigned to
<i>IfcBuildingElementProxy</i> overrides the properties assigned to
<i>IfcBuildingElementProxyType</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcBuildingElementProxy</i>, as any subtype of
<i>IfcBuildingElement</i>, may participate in two different
containment relationships. The first (and in most implementation
scenarios mandatory) relationship is the hierachical spatial
containment, the second (optional) relationship is the aggregation
within an&nbsp;element assembly.</p>
<ul>
<li>The <i>IfcBuildingElementProxy</i> is places within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of&nbsp;<i>IfcSpatialStructureElement</i> are valid
spatial containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
<li>The <i>IfcBuildingElementProxy</i> may be aggregated into an
element assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this case
it should not be additionally contained in the project spatial
hierarchy, i.e.&nbsp;<i>SELF\IfcElement.ContainedInStructure</i>
should be <i>NIL.</i></li>
</ul>
<p><u><b>Geometry Use Definition</b></u></p>
<p>The geometric representation of <i>IfcBuildingElementProxy</i>
is given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for any <i>IfcBuildingElementProxy</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations. The local
placement can be given relativly.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to a
spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><u><b>Geometric Representation</b></u></p>
<p>Currently, the 'FootPrint', 'Body', and 'Box' representations
are supported. The 'Box' representation includes the representation
type 'BoundingBox' and is explained at
<i>IfcBuildingElement</i>.</p>
<p><b>FootPrint Representation</b></p>
<p>Any building element proxy may be represented by a geometric
curve set, given by a collection of 2D points and curves. The foot
pring geometric representation of <i>IfcBuildingElementProxy</i> is
defined using the 'FootPrint' representation.</p>
<ul>
<li><i>RepresentationIdentifier</i>: 'FootPrint'</li>
<li><i>RepresentationType</i>: 'GeometricCurveSet',
'Annotation2D'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcBuildingElementProxy</i> can be
represented using the representation types 'GeometricSet',
'SweptSolid', 'CSG' 'SurfaceModel', 'Brep', and
'MappedRepresentation'. The representation types 'SurfaceModel',
'Brep', and 'MappedRepresentation' are explained at
<i>IfcBuildingElement</i>.</p>
<p><i>GeometricSet Representation Type</i></p>
<p>Any building element proxy may be represented by a geometric
set, given by a collection of 2D and 3D points, curves, and
surfaces. It represents the body of the proxy object, when no
topological structure is available. The following attribute values
for the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i>: 'Body'</li>
<li><i>RepresentationType</i>: 'GeometricSet'</li>
</ul>
<p><i>SweptSolid Representation Type</i></p>
<p>Any building element proxy may be represented by swept solid
geometry (either by extrusion or by revolution). The following
attribute values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i>: 'Body'</li>
<li><i>RepresentationType</i>: 'SweptSolid'</li>
</ul>
<p>No further restrictions (e.g., for the profile or extrusion
direction) are defined at this level. A single or multiple swept
area solid(s) can be the <i>Items</i> of the
<i>IfcShapeRepresentation</i>.</p>
<p><i>CSG Representation Type</i></p>
<p>Any building element proxy may be represented by a CSG primitive
or CSG tree. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i>: 'Body'</li>
<li><i>RepresentationType</i>: 'CSG'</li>
</ul>
<p>No further restrictions (e.g., for the depths of the CSG tree)
are defined at this level.</p>
</EPM-HTML>"
1526;IfcCovering;"<EPM-HTML> 
<p><u>Definition from ISO 6707-1:1989</u>: term used: Finishing -
final coverings and treatments of surfaces and their
intersections.</p>
<p>A covering is an element which
covers some part of another element and is fully dependent on
that other element. The <i>IfcCovering</i> defines the occurrence
of a covering type, that (if given) is expressed by the
<i>IfcCoveringType</i>. Examples of coverings include wall
claddings, floorings and suspended ceilings. Coverings are
elements with relationships to the covered element and the space
on the other side, they may contain openings, assigned by
<i>IfcRelVoidsElement</i>, material information, assigned by
<i>IfcRelAssociatesMaterial</i>, and others.</p>
<blockquote><small>NOTE A more basic information about claddings,
floorings, and ceilings of a space can be attached to
<i>IfcSpace</i>'s using the Pset_SpaceCommon properties. Then
only a name can be provided and the covering quantities would be
interpreted from the space quantities.</small></blockquote>
<p>Coverings can be assigned to</p>
<ul>
<li>a space represented by <i>IfcSpace</i>
<ul>
<li>using the inverse relationship <i>CoversSpaces</i> pointing
to <i>IfcRelCoversSpaces</i>. The space is then accessible via
<i>IfcRelCoversSpaces.RelatedSpace</i>. It defines to which space
a covering is facing towards.
<ul style=""list-style-type:none"">
<li><small>NOTE The mere containment relationship between an
<small>IfcCovering</small> and an <small>IfcSpace</small> is
created by using
<small>IfcRelContainedInSpatialStructure</small></small></li>
</ul>
</li>
</ul>
</li>
<li>a space boundary represented by <i>IfcRelSpaceBoundary</i>
<ul>
<li>using the inverse relationship <i>ProvidesBoundaries</i>
pointing to <i>IfcRelSpaceBoundary.</i> The space is then
accessible via <i>IfcRelSpaceBoundary.RelatingSpace</i>.</li>
</ul>
</li>
<li>a building element represented by <i>IfcBuildingElement</i>
<ul>
<li>using the inverse relationship <i>Covers</i> pointing to
<i>IfcRelCoversBldgElements</i>. The building element is then
accessible via
<i>IfcRelCoversBldgElements.RelatingBuildingElement</i>.</li>
</ul>
</li>
</ul>
<p>The following guideline shall apply:</p>
<ul>
<li>(default) if the space has coverings that may not have an own
shape representation and no defined relationships to the building
elements they cover, then the <i>IfcCovering</i> shall be
assigned to <i>IfcSpace</i> using the <i>IfcRelCoversSpaces</i>
relationship,</li>
<li>if the space has coverings that have an own shape
representation and the space has defined space boundaries, then
the covering, which relates to that space, may be assigned to the
space boundaries using the link
to˙<i>IfcRelSpaceBoundary,</i></li>
<li>if the covering does not relate to a space, then the covering
should be assigned to the building element or a distribution
element using the <i>IfcRelCoversBldgElements</i>
relationship.</li>
</ul>
<blockquote class=""history"">HISTORY New entity in IFC Release 1.0.</blockquote>
<blockquote class=""change-ifc2x"">IFC2x CHANGE The attribute <i>PredefinedType</i> is now optional and should only be inserted when no type information, given by <i>IfcCoveringType</i>, is assigned to the <i>IfcCovering</i> occurrence by <i>IfcRelDefinesByType</i>.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE The <i>IfcCovering</i> is restricted to coverings of building elements by having
<i>RelatingBuildingElement</i> pointing to <i>IfcBuildingElement</i>.</blockquote>

<p><u><b>Type Use Definition</b></u></p>
<p>The <i>IfcCovering</i> defines the occuurence of any covering,
common information about covering types (or styles) is handled by
<i>IfcCoveringType</i>. The <i>IfcCoveringType</i> (if present)
may establish the common˙type name, usage (or predefined) type,
common set of properties, common material layer set, and common
shape representations (using <i>IfcRepresentationMap</i>). The
<i>IfcCoveringType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p>As an additional use agreement for standard coverings (i.e.
slabs with constant thickness along the extrusion direction), the
<i>IfcCoveringType</i> should have a unique
<i>IfcMaterialLayerSet</i>, that is referenced by
the˙<i>IfcMaterialLayerSetUsage</i> assigned to all occurrences
of this covering type.</p>

<p>Figure 91 illustrates assignment of <i>IfcMaterialLayerSetUsage</i> and <i>IfcMaterialLayerSet</i> to the covering type and the covering occurrence.</small></p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td><img alt=""Material layer set and usage"" src=""figures/IfcCovering_MaterialUsage-01.png"" height=""220"" width=""501""></td></tr>
<tr><td><p class=""figure"">Figure 91 &mdash; Covering material usage</p></td></tr>
</table>

<p>If an <i>IfcCoveringType</i> is assigned to the
<i>IfcCovering</i>, the attribute <i>PredefinedType</i> shall not
be assigned, or shall be identical to
<i>IfcCoveringType.PredefinedType</i>.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcCovering</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcCovering</i> are
part of this IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CoveringCommon.xml"" target=
""SOURCE"">Pset_CoveringCommon</a>: common property set for all
covering occurrences
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CoveringCeiling.xml""
target=""SOURCE"">Pset_CoveringCeiling</a>: specific property set
for all occurrences of coverings with the PredefinedType:
CEILING</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CoveringFlooring.xml""
target=""SOURCE"">Pset_CoveringFlooring</a>: specific property set
for all occurrences of coverings with the PredefinedType:
FLOORING</li>
</ul>
</li>
</ul>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcCovering</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities can be defined being subjected to local standard of
measurement with another string value assigned to <i>Name</i> and
a value provided for <i>MethodOfMeasurement</i>. Quantities shall
never be assigned to the <i>IfcCoveringType</i>.</p>
<ul>
<li><a href=
""../../qto/IfcSharedBldgElements/Qto_CoveringBaseQuantities.xml""
target=""SOURCE"">Qto_CoveringBaseQuantities</a>: base quantities
for all covering occurrences.</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcCovering</i> has a containment relationship within
the hierarchical spatial structure.</p>
<ul>
<li>The <i>IfcCovering</i> is places within the project spatial
hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of <i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcSpace</i> being the default
container.</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u></p>
<p>The geometric representation of <i>IfcCovering</i> is given by
the <i>IfcProductDefinitionShape</i>, allowing multiple geometric
representation. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcCovering</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the same
<i>IfcSpatialStructureElement</i> , which is used in the
<i>ContainedInStructure</i> inverse attribute, or to a spatial
structure element at a higher level, referenced by that.</li>
<li>If the <i>IfcCovering</i>, however, is assigned to an
<i>IfcBuildingElement</i>, and this element defines its own local
placement, than the <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the <i>IfcBuildingElement</i>.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><i><b>Geometric Representations</b></i></p>
<p>The geometric representation of the <i>IfcCovering</i> depends
on two criteria:</p>
<ol>
<li>Does it define an area or a volume?</li>
<li>Is the base surface (either the <i>IfcRelSpaceBoundary</i> or
the surface of the <i>IfcBuildingElement</i> it relates to) a
planar surface or a cylindrical surface?</li>
</ol>
<p><b>GeometricSet Representation</b></p>
<p>The 'GeometricSet' geometric representation of
<i>IfcCovering</i> supports area definitions as 3D surfaces.˙</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'GeometricSet'</li>
</ul>
<p>The following additional constraints apply to the
'GeometricSet' representation of <i>IfcCovering</i>:</p>
<ul>
<li>for planar base surfaces - bounded surface
representation</li>
<li>for cylindrical base surfaces - swept surface
representation</li>
</ul>

<p>Figure 92 illustrates a planar surface representation where the area of <i>IfcCovering</i> is given by an <i>IfcPolyLoop</i> for planar base surfaces (here given by the <i>IfcRelSpaceBoundary</i>).</p>
<ul>
<li>The implicit planar surface of the <i>IfcPolyLoop</i> shall be identical with the planar surface defined by the <i>IfcRelSpaceBoundary</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcCovering_Standard-1-Layout1.gif"" alt=""standard planar covering"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 92 &mdash; Covering surface planar</p></td></tr>
</table>

<p>Figure 93 illustrates a cylindrical surface representation where the area of the <i>IfcCovering</i> is given by an <i>IfcSurfaceOfLinearExtrusion</i> for cylindrical base surfaces (here given by the <i>IfcRelSpaceBoundary</i> - such as caused by a round wall).</p>
<ul>
<li>The geometry representation of the <i>IfcCovering</i> is given by the <i>IfcTrimmedCurved</i> (the Curve parameter of the
<i>IfcArbitraryOpenProfileDef</i> - in cases of faceted representation also an <i>IfcPolyline</i>). It is extruded within the plane of the base surface using the <i>Depth</i> parameter of the <i>IfcSurfaceOfLinearExtrusion</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcCovering_Standard-2-Layout1.gif"" alt=""standard cylindrical covering"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 93 &mdash; Covering surface cylindrical</p></td></tr>
</table>

<p><b>SweptSolid Representation</b></p>
<p>The 'SweptSolid' geometric representation of
<i>IfcCovering</i> supports volume definitions as 3D solids.˙</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the 'SweptSolid'
representation of <i>IfcCovering</i>:</p>
<ul>
<li>for planar base surfaces - swept area representation</li>
<li>for cylindrical base surfaces - swept area
representation</li>
</ul>

<p>Figure 94 illustrates a body representation where the volume of <i>IfcCovering</i> is given by an <i>IfcExtrudedAreaSolid</i> for planar base surfaces (here given by the <i>IfcRelSpaceBoundary</i>).</p>
<ul>
<li>The extruded area (<i>IfcArbitraryClosedProfileDef</i>) shall be coplanar to the surface defined by the <i>IfcRelSpaceBoundary</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcCovering_Advanced-1-Layout1.gif"" alt=""advanded solid covering"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 94 &mdash; Covering body planar</p></td></tr>
</table>

<p>Figure 95 illustrates a body representation where the volume of the <i>IfcCovering</i> is given by an <i>IfcExtrudedAreaSolid</i> for cylindrical base surfaces (here given by the <i>IfcRelSpaceBoundary</i> - such as caused by a round wall).</p>
<ul>
<li>The geometry representation of the <i>IfcCovering</i> is given by the <i>IfcCompositeCurve</i> (the <i>OuterCurve</i> parameter of the
<i>IfcArbitraryClosedProfileDef</i> - in cases of faceted representation also a closed <i>IfcPolyline</i>). It is extruded along the plane of the base surface using the <i>Depth</i> parameter of the <i>IfcSurfaceOfLinearExtrusion</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=""figures/IfcCovering_Advanced-2-Layout1.gif"" alt=""advanced solid covering"" border=""0"" height=""274"" width=""399""></td></tr>
<tr><td><p class=""figure"">Figure 95 &mdash; Covering body circular</p></td></tr>
</table>

</EPM-HTML>"
1543;IfcRelCoversBldgElements;"<EPM-HTML> 
<p><u>Definition from IAI</u>: The
<i>IfcRelCoversBldgElements</i> is an objectified relationship
between an element and one to many coverings, which cover the
building element.</p>
<ul>
<li><i>IfcRelCoversBldgElements</i>, this relationship, expresses
the primary relation to the element,</li>
<li><i>IfcRelCoversSpaces</i> expresses the primary relation to
the space.</li>
</ul>
<blockquote><small><font color=""#0000FF"">HISTORY New Entity in
IFC Release 1.5</font></small></blockquote>
<blockquote><small><font color=""#FF0000"">IFC2x4 CHANGE: The data
type of the attribute <i>RelatingElement</i> has been changed
from <i>IfcElement</i> to its subtype
<i>IfcBuildingElement</i>.</font></small></blockquote>
</EPM-HTML>"
1546;IfcShadingDevice;"<EPM-HTML>
<p><u>Definition from IAI</u>: Shading devices are purpose built
devices to protect from the sunlight, from natural light, or
screening them from view. Shading devices can form part of the
facade or can be mounted inside the building, they can be fixed
or operable.</p>
<blockquote><small>NOTE Also other building elements such as
protruding slabs or balconies can act as shading devices. Those
elements however have another primary purpose and are defined as
<i>IfcSlab</i> or by other subtypes of <i>IfcBuildingElement</i>.
The particular additional purpose as a shading device is provided
by assigning the property set <i>Pset_ElementShading</i> to those
building elements.</small></blockquote>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4</font></small></blockquote>
</EPM-HTML>"
1556;IfcSlabType;"<EPM-HTML>
<p>The element type <i>IfcSlabType</i> defines commonly shared
information for occurrences of slabs. The set of shared information
may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common material layer definitions</li>
<li>common shape representations</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE It is illegal to share shape
representations as representation maps for occurrences of
<i>IfcSlabStandardCase</i>.</small></blockquote>
</li>
</ul>
<p>It is used to define a slab specification (i.e. the specific
product information, that is common to all occurrences of that
product type). Slab types may be exchanged without being already
assigned to occurrences.</p>
<blockquote><small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element occurrence
instance through the <i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>The occurrences of the <i>IfcSlabType</i> within building models
are represented by instances of <i>IfcSlabStandardCase</i> if the
<i>IfcSlabType</i> has a single associated
<i>IfcMaterialLayerSet</i>; otherwise they are represented by
instances of <i>IfcSlab</i>, or <i>IfcSlabElementedCase</i>.</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">HISTORY&nbsp; New
entity in Release IFC2x2.</span></p>
</blockquote>
<p><u>Informal proposition</u>:</p>
<ol>
<li>The material assignment, if provided using the
<i>IfcRelAssociatesMaterial</i> relationship, shall not reference
the <i>IfcMaterialLayerSetUsage</i>.</li>
</ol>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcSlabType</i> is defined by the
<i>IfcMaterialLayerSet</i> or as fall back by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcSlabType</i>, if there is at least
one occurrences. of <i>IfcSlabStandardCase</i> for this
type.</small></blockquote>
<p><u><b>Layer Set Use Definition</b></u>:</p>
<p>The shared material layer set definition is defined by assigning
an <i>IfcMaterialLayerSet</i> (see material use definition above).
The <i>IfcMaterialLayer</i> refers to one or several of
<i>IfcMaterial</i> that is the common for all slab occurrence, if
used. It is only applicable if the <i>IfcSlabType</i> has only
occurrences of type <i>IfcSlabStandardCase</i> (see definition of
<i>IfcSlabStandardCase</i> for further information).</p>
<blockquote><small>NOTE Since each individual instance of
<i>IfcSlabStandardCase</i> defines its own
<i>IfcMaterialLayerSetUsage</i> including the offset from the
reference plane, the same <i>IfcSlabType</i> can be used
independently of the reference plane alignment of its
occurrences.</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcSlabType</i> are
defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcWallType</i> are part of this IFC
release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcSlabType</i> and those that are only assignable to
<i>IfcSlab</i>. If the same property is assigned to the
<i>IfcSlabType</i> and the <i>IfcSlab</i> being an occurrence of
the <i>IfcSlabType</i>, then the occurrence property overrides the
type property.</small></blockquote>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_SlabCommon.xml""
target=""SOURCE"">Pset_SlabCommon</a>: common property set for all
slab types.</li>
</ul>
</EPM-HTML>"
1559;IfcWallType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcWallType</i> defines commonly shared information for
occurrences of walls. The set of shared information may
include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common material layer definitions</li>
<li>common shape representations</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE It is illegal to share shape
representations as representation maps for occurrences of
<i>IfcWallStandardcase</i>.</small></blockquote>
</li>
</ul>
<p>It is used to define a wall specification (i.e. the specific
product information, that is common to all occurrences of that
product type). Wall types may be exchanged without being already
assigned to occurrences.</p>
<blockquote>
<p><font size=""-1"">NOTE: The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</font></p>
</blockquote>
<p>Occurrences of the <i>IfcWallType</i> within building models
are represented by instances of <i>IfcWallStandardCase</i> if the
<i>IfcBeamType</i> has a single associated
<i>IfcMaterialLayerSet</i>; otherwise they are represented by
instances of <i>IfcWall</i>, or <i>IfcWallElementedCase</i>.
Occurrences of the <i>IfcWallType</i> within structural analysis
models are represented by instances of
<i>IfcStructuralSurfaceMember</i>, or its applicable
subtypes.</p>
<blockquote><small><font color=""#0000FF"">HISTORY: New entity in
Release IFC2x Editon 2.</font></small></blockquote>
<p><u>Informal proposition</u>:</p>
<ol>
<li>The material assignment, if provided using the
<i>IfcRelAssociatesMaterial</i> relationship, shall not reference
the <i>IfcMaterialLayerSetUsage</i>.</li>
</ol>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcWallType</i> is defined by the
<i>IfcMaterialLayerSet</i> or as fall back by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcWallType</i>, if there is at least
one occurrences. of <i>IfcWallStandardCase</i> for this
type.</small></blockquote>
<p><u><b>Layer Set Use Definition</b></u>:</p>
<p>The shared material layer set definition is defined by
assigning an <i>IfcMaterialLayerSet</i> (see material use
definition above). The <i>IfcMaterialLayer</i> refers to one or
several of <i>IfcMaterialLayer</i> that is the common for all
wall occurrence, if used. It is only applicable if the
<i>IfcWallType</i> has only occurrences of type
<i>IfcWallStandardCase</i> (see definition of
<i>IfcWallStandardCase</i> for further information).</p>
<blockquote><small>NOTE Since each individual instance of
<i>IfcWallStandardCase</i> defines its own
<i>IfcMaterialLayerSetUsage</i> including the offset from the
wall axis, the same <i>IfcWallType</i> can be used independently
of the axis alignment of its occurrences.</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcWallType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcWallType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcWallType</i> and those that are only assignable to
<i>IfcWall</i>. If the same property is assigned to the
<i>IfcWallType</i> and the <i>IfcWall</i> being an occurrence of
the <i>IfcWallType</i>, then the occurrence property overrides
the type property.</small></blockquote>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_WallCommon.xml""
target=""SOURCE"">Pset_WallCommon</a>: common property set for all
wall types.</li>
</ul>
</EPM-HTML>"
1562;IfcStairFlightType;"<EPM-HTML>
	 <P><U>Definition from IAI</U>: The element type (<I>IfcStairFlightType</I>)
		defines a list of commonly shared property set definitions of a stair flight
		and an optional set of product representations. It is used to define an stair
		flight specification (i.e. the specific product information, that is common to
		all occurrences of that product type).</P> 
	 <BLOCKQUOTE> 
		<P><FONT SIZE=""-1"">NOTE: The product representations are defined as
		  representation maps (at the level of the supertype <I>IfcTypeProduct</I>, which
		  gets assigned by an element occurrence instance through the
		  <I>IfcShapeRepresentation.Item[1]</I> being an
		  <I>IfcMappedItem</I>.</FONT></P></BLOCKQUOTE> 
	 <P>A stair flight type is used to define the common properties of a certain
		type of a stair flight that may be applied to many instances of that type to
		assign a specific style. Stair flight types may be exchanged without being
		already assigned to occurrences.</P> 
	 <P>The occurrences of the <I>IfcStairFlightType</I> are represented by
		instances of <I>IfcStairFlight</I>.</P> 
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1"">HISTORY: New entity in Release IFC2x
		  Edition 2.</FONT></P></BLOCKQUOTE>
</EPM-HTML>"
1565;IfcRailingType;"<EPM-HTML>
	 <P><U>Definition from IAI</U>: The element type (<I>IfcRailingType</I>)
		defines a list of commonly shared property set definitions of a railing element
		and an optional set of product representations. It is used to define a railing
		specification (i.e. the specific product information, that is common to all
		occurrences of that product type).</P> 
	 <BLOCKQUOTE> 
		<P><FONT SIZE=""-1"">NOTE: The product representations are defined as
		  representation maps (at the level of the supertype <I>IfcTypeProduct</I>, which
		  gets assigned by an element occurrence instance through the
		  <I>IfcShapeRepresentation.Item[1]</I> being an
		  <I>IfcMappedItem</I>.</FONT></P></BLOCKQUOTE> 
	 <P>A railing type is used to define the common properties of a certain type
		of railing that may be applied to many instances of that type to assign a
		specific style. Railing types may be exchanged without being already assigned
		to occurrences.</P> 
	 <P>The occurrences of the <I>IfcRailingType</I> are represented by
		instances of <I>IfcRailing</I>.</P> 
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1"">HISTORY New entity in Release IFC2x
		  Editon 2.</FONT></P></BLOCKQUOTE>
</EPM-HTML>"
1568;IfcRampFlightType;"<EPM-HTML>
	 <P><U>Definition from IAI</U>: The element type (<I>IfcRampFlightType</I>)
		defines a list of commonly shared property set definitions of a ramp flight and
		an optional set of product representations. It is used to define an ramp flight
		specification (i.e. the specific product information, that is common to all
		occurrences of that product type).</P> 
	 <BLOCKQUOTE> 
		<P><FONT SIZE=""-1"">NOTE: The product representations are defined as
		  representation maps (at the level of the supertype <I>IfcTypeProduct</I>, which
		  gets assigned by an element occurrence instance through the
		  <I>IfcShapeRepresentation.Item[1]</I> being an
		  <I>IfcMappedItem</I>.</FONT></P></BLOCKQUOTE> 
	 <P>A ramp flight type is used to define the common properties of a certain
		type of a ramp flight that may be applied to many instances of that type to
		assign a specific style. Ramp flight types may be exchanged without being
		already assigned to occurrences.</P> 
	 <P>The occurrences of the <I>IfcRampFlightType</I> are represented by
		instances of <I>IfcRampFlight</I>.</P> 
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1"">HISTORY New entity in Release IFC2x
		  Edition 2.</FONT></P></BLOCKQUOTE>
</EPM-HTML>"
1571;IfcBeamType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcBeamType</i> defines commonly shared information for
occurrences of beams. The set of shared information may
include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common profile definitions</li>
<li>common shape representations</li>
</ul>
<p>It is used to define a beam specification, or beam style (i.e.
the specific product information that is common to all
occurrences of that beam type). Beam types may be exchanged
without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcBeamType</i> within building models
are represented by instances of <i>IfcBeamStandardCase</i> if the
<i>IfcBeamType</i> has a single associated
<i>IfcMaterialProfileSet</i>; otherwise they are represented by
instances of <i>IfcBeam</i>. Occurrences of the
<i>IfcBeamType</i> within structural analysis models are
represented by instances of <i>IfcStructuralCurveMember</i>, or
its applicable subtypes.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
Release IFC2x Edition 2.</font></small></blockquote>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcBeamType</i> is defined by the
<i>IfcMaterialProfileSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcBeamType</i>, if there is at least
one occurrences. of <i>IfcBeamStandardCase</i> for this
type.</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcBeamType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcBeamType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcBeamType</i> and those that are only assignable to
<i>IfcBeam</i>. If the same property is assigned to the
<i>IfcBeamType</i> and the <i>IfcBeam</i> being an occurrence of
the <i>IfcBeamType</i>, then the occurrence property overrides
the type property.</small></blockquote>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_BeamCommon.xml""
target=""SOURCE"">Pset_BeamCommon</a>: common property set for all
beam types.</li>
</ul>
<p><u><b>Profile Use Definition</b></u>:</p>
<p>The shared profile definition is defined by assigning an
<i>IfcMaterialProfileSet</i> (see material use definition above).
The <i>IfcMaterialProfile</i> refers to the subtype of
<i>IfcProfileDef</i> that is the common profile for all beam
occurrence, if used. It is only applicable if the
<i>IfcBeamType</i> has only occurrences of type
<i>IfcBeamStandardCase</i> (see definition of
<i>IfcBeamStandardCase</i> for further information).</p>
<blockquote><small>NOTE The attribute <i>ProfileName</i> of the
<i>IfcProfileDef</i> subtype, referenced in
<i>IfcMaterialProfile</i> should contain a standardized profile
name according to local standards. However, an additional
geometric representation of the profile is necessary (e.g. as
<i>IfcExtrudedAreaSolid</i>). An importing application is allowed
to check for the existence of the profile name: in case of
identifying it as a standardized name, the corresponding profile
geometry and possibly other cross sectional properties can be
read from a library. Otherwise the geometric representation and
possible non geometric <i>IfcProfileProperties</i> have to be
used.</small></blockquote>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcBeamType</i> may define the shared geometric
representation for all beam occurrences. The
<i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an <i>RepresentationIdentifier</i> 'Box', 'Axis', or 'Body'). It
is only applicable if the <i>IfcBeamType</i> has only occurrences
of type <i>IfcBeam</i> (See geometric use definition of
<i>IfcBeam</i> for further information).</p>
<blockquote><small>NOTE If the <i>IfcBeamType</i> has an
associated <i>IfcMaterialProfileSet</i>, then no shared geometric
representation shall be provided.</small></blockquote>
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcBeam</i> and
<i>IfcBeamStandardCase</i></small></blockquote>
</EPM-HTML>"
1574;IfcColumnType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcColumnType</i> defines commonly shared information for
occurrences of columns. The set of shared information may
include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common profile definitions</li>
<li>common shape representations</li>
</ul>
<p>It is used to define a column specification, or column style
(i.e. the specific product information that is common to all
occurrences of that column type). Column types may be exchanged
without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcColumnType</i> within building models
are represented by instances of <i>IfcColumnStandardCase</i> if
the <i>IfcColumnType</i> has a single associated
<i>IfcMaterialProfileSet</i>; otherwise they are represented by
instances of <i>IfcColumn</i>. Occurrences of the
<i>IfcColumnType</i> within structural analysis models are
represented by instances of <i>IfcStructuralCurveMember</i>, or
its applicable subtypes.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
Release IFC2x Edition 2.</font></small></blockquote>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcColumnType</i> is defined by the
<i>IfcMaterialProfileSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcColumnType</i>, if there is at
least one occurrences of <i>IfcColumnStandardCase</i> for this
type.</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcColumnType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcColumnType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcColumnType</i> and those that are only assignable to
<i>IfcColumn</i>. If the same property is assigned to the
<i>IfcColumnType</i> and the <i>IfcColumn</i> being an occurrence
of the <i>IfcColumnType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_ColumnCommon.xml"" target=
""SOURCE"">Pset_ColumnCommon</a>: common property set for all
column types.</li>
</ul>
<p><u><b>Profile Use Definition</b></u>:</p>
<p>The shared profile definition is defined by assigning an
<i>IfcMaterialProfileSet</i> (see material use definition above).
The <i>IfcMaterialProfile</i> refers to the subtype of
<i>IfcProfileDef</i> that is the common profile for all column
occurrence, if used. It is only applicable if the
<i>IfcColumnType</i> has only occurrences of type
<i>IfcColumnStandardCase</i> (see definition of
<i>IfcColumnStandardCase</i> for further information).</p>
<blockquote><small>NOTE The attribute <i>ProfileName</i> of the
<i>IfcProfileDef</i> subtype, referenced in
<i>IfcMaterialProfile</i> should contain a standardized profile
name according to local standards. However, an additional
geometric representation of the profile is necessary (e.g. as
<i>IfcExtrudedAreaSolid</i>). An importing application is allowed
to check for the existence of the profile name: in case of
identifying it as a standardized name, the corresponding profile
geometry and possibly other cross sectional properties can be
read from a library. Otherwise the geometric representation and
possible non geometric <i>IfcProfileProperties</i> have to be
used.</small></blockquote>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcColumnType</i> may define the shared geometric
representation for all column occurrences. The
<i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an <i>RepresentationIdentifier</i> 'Box', 'Axis', or 'Body'). It
is only applicable if the <i>IfcColumnType</i> has only
occurrences of type <i>IfcColumn</i> (See geometric use
definition of <i>IfcColumn</i> for further information).</p>
<blockquote><small>NOTE If the <i>IfcColumnType</i> has an
associated <i>IfcMaterialProfileSet</i>, then no shared geometric
representation shall be provided.</small></blockquote>
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcColumn</i> and
<i>IfcColumnStandardCase</i></small></blockquote>
</EPM-HTML>"
1577;IfcMemberType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcMemberType</i> defines commonly shared information for
occurrences of members. Members are predominately linear building
elements, often forming part of a structural system. The
orientation of the member (being horizontal, vertical or sloped)
is not relevant to its definition (in contrary to beam and
column). The set of shared information may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common profile definitions</li>
<li>common shape representations</li>
</ul>
<p>It is used to define a member specification, or member style
(i.e. the specific product information that is common to all
occurrences of that member type). Member types may be exchanged
without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcMemberType</i> within building models
are represented by instances of <i>IfcMemberStandardCase</i> if
the <i>IfcMemberType</i> has a single associated
<i>IfcMaterialProfileSet</i>; otherwise they are represented by
instances of <i>IfcMember</i>. Occurrences of the
<i>IfcMemberType</i> within structural analysis models are
represented by instances of <i>IfcStructuralCurveMember</i>, or
its applicable subtypes.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
Release IFC2x2 Addendum 1.</font></small></blockquote>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcMemberType</i> is defined by the
<i>IfcMaterialProfileSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcMemberType</i>, if there is at
least one occurrences of <i>IfcMemberStandardCase</i> for this
type.</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcMemberType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcMemberType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcMemberType</i> and those that are only assignable to
<i>IfcMember</i>. If the same property is assigned to the
<i>IfcMemberType</i> and the <i>IfcMember</i> being an occurrence
of the <i>IfcMemberType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_MemberCommon.xml"" target=
""SOURCE"">Pset_MemberCommon</a>: common property set for all
member types.</li>
</ul>
<p><u><b>Profile Use Definition</b></u>:</p>
<p>The shared profile definition is defined by assigning an
<i>IfcMaterialProfileSet</i> (see material use definition above).
The <i>IfcMaterialProfile</i> refers to the subtype of
<i>IfcProfileDef</i> that is the common profile for all member
occurrence, if used. It is only applicable if the
<i>IfcMemberType</i> has only occurrences of type
<i>IfcMemberStandardCase</i> (see definition of
<i>IfcMemberStandardCase</i> for further information).</p>
<blockquote><small>NOTE The attribute <i>ProfileName</i> of the
<i>IfcProfileDef</i> subtype, referenced in
<i>IfcMaterialProfile</i> should contain a standardized profile
name according to local standards. However, an additional
geometric representation of the profile is necessary (e.g. as
<i>IfcExtrudedAreaSolid</i>). An importing application is allowed
to check for the existence of the profile name: in case of
identifying it as a standardized name, the corresponding profile
geometry and possibly other cross sectional properties can be
read from a library. Otherwise the geometric representation and
possible non geometric <i>IfcProfileProperties</i> have to be
used.</small></blockquote>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcMemberType</i> may define the shared geometric
representation for all member occurrences. The
<i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an <i>RepresentationIdentifier</i> 'Box', 'Axis', or 'Body'). It
is only applicable if the <i>IfcMemberType</i> has only
occurrences of type <i>IfcMember</i> (See geometric use
definition of <i>IfcMember</i> for further information).</p>
<blockquote><small>NOTE If the <i>IfcMemberType</i> has an
associated <i>IfcMaterialProfileSet</i>, then no shared geometric
representation shall be provided.</small></blockquote>
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcMember</i> and
<i>IfcMemberStandardCase</i></small></blockquote>
</EPM-HTML>"
1580;IfcCurtainWallType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type (<i>IfcCurtainWallType</i>)
defines a list of commonly shared property set definitions of a curtain
wall element and an optional set of product representations. It is used
to define a curtain wall specification (i.e. the specific product
information, that is common to all occurrences of that product type).</p>
<blockquote>
  <p><font size=""-1"">NOTE: The product
representations are defined as representation maps (at the level of the
supertype <i>IfcTypeProduct</i>, which gets assigned by an
element occurrence instance through the <i>IfcShapeRepresentation.Item[1]</i>
being an <i>IfcMappedItem</i>.</font></p>
</blockquote>
<p>A curtain wall type is used to define the common properties of
a certain type of curtain wall that may be applied to many instances of
that type to assign a specific style. Curtain wall types may be
exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcCurtainWallType</i>
are represented by instances of <i>IfcCurtainWall.</i></p>
<blockquote>
  <p><font color=""#0000ff"" size=""-1"">HISTORY
New entity in Release IFC2x Editon 3.</font></p>
</blockquote>
</EPM-HTML>"
1583;IfcPlateType;"<EPM-HTML>
<p>The element type <i>IfcPlateType</i> defines commonly shared
information for occurrences of plates. The set of shared
information may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common material layer definitions</li>
<li>common shape representations</li>
<li style=""list-style-type:none"">
<blockquote><small>NOTE It is illegal to share shape
representations as representation maps for occurrences of
<i>IfcPlateStandardCase</i>.</small></blockquote>
</li>
</ul>
<p>It is used to define a plate specification (i.e. the specific
product information, that is common to all occurrences of that
product type). Plate types may be exchanged without being already
assigned to occurrences.</p>
<blockquote><small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element occurrence
instance through the <i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>The occurrences of the <i>IfcPlateType</i> within building
models are represented by instances of <i>IfcPlateStandardCase</i>
if the <i>IfcPlateType</i> has a single associated
<i>IfcMaterialLayerSet</i>; otherwise they are represented by
instances of <i>IfcPlate</i>.</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">HISTORY&nbsp; New
entity in Release IFC2x2.</span></p>
</blockquote>
<p><u>Informal proposition</u>:</p>
<ol>
<li>The material assignment, if provided using the
<i>IfcRelAssociatesMaterial</i> relationship, shall not reference
the <i>IfcMaterialLayerSetUsage</i>.</li>
</ol>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcPlateType</i> is defined by the
<i>IfcMaterialLayerSet</i> or as fall back by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i> relationship.</p>
<blockquote><small>Note: It is illegal to assign an
<i>IfcMaterial</i> to an <i>IfcPlateType</i>, if there is at least
one occurrences of <i>IfcPlateStandardCase</i> for this
type.</small></blockquote>
<p><u><b>Layer Set Use Definition</b></u>:</p>
<p>The shared material layer set definition is defined by assigning
an <i>IfcMaterialLayerSet</i> (see material use definition above).
The <i>IfcMaterialLayer</i> refers to one or several of
<i>IfcMaterial</i> that is the common for all plate occurrence, if
used. It is only applicable if the <i>IfcPlateType</i> has only
occurrences of type <i>IfcPlateStandardCase</i> (see definition of
<i>IfcPlateStandardCase</i> for further information).</p>
<blockquote><small>NOTE Since each individual instance of
<i>IfcPlateStandardCase</i> defines its own
<i>IfcMaterialLayerSetUsage</i> including the offset from the
reference plane, the same <i>IfcPlateType</i> can be used
independently of the reference plane alignment of its
occurrences.</small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcPlateType</i> are
defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcWallType</i> are part of this IFC
release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcPlateType</i> and those that are only assignable to
<i>IfcPlate</i>. If the same property is assigned to the
<i>IfcPlateType</i> and the <i>IfcPlate</i> being an occurrence of
the <i>IfcPlateType</i>, then the occurrence property overrides the
type property.</small></blockquote>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_PlateCommon.xml""
target=""SOURCE"">Pset_PlateCommon</a>: common property set for all
plate types.</li>
</ul>
</EPM-HTML>"
1586;IfcStairType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The element type
      <i>IfcStairType</i> defines a list of commonly shared
      property set definitions of a stair and an optional set of
      product representations. It is used to define a stair
      specification (i.e. the specific product information, that
      is common to all occurrences of that product type).
    </p>
    <blockquote>
      <small>NOTE The product representations are defined as
      representation maps (at the level of the supertype
      <i>IfcTypeProduct</i>, which gets assigned by an element
      occurrence instance through the
      <i>IfcShapeRepresentation.Item[1]</i> being an
      <i>IfcMappedItem</i>.</small>
    </blockquote>
    <p>
      An <i>IfcStairType</i>˙is used to define the common
      properties of a specific stair that may be applied to many
      instances of that type to assign a specific style. 
      Building element types (or the instantiable subtypes) 
      may be exchanged without being
      already assigned to occurrences.
    </p>
    <p>
      The <i>IfcStairType</i> can have common material (using the
      inverse relationship <i>HasAssociations</i>) or property
      set information (using <i>HasPropertySets</i>) assigned. If
      present, it does apply equally to all occurrences of the
      <i>IfcStairType</i>. Property set information may be
      overridden at the occurrence.
    </p>
    <p>
      The occurrences of the <i>IfcStairType</i> are represented
      by instances of <i>IfcStair</i>.
    </p>
    <blockquote>
      <small><font color=""#0000FF"">HISTORY New entity in Release
      IFC2x Edition 4.</font></small>
    </blockquote>

</EPM-HTML>"
1589;IfcRampType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The element type
      <i>IfcRampType</i> defines a list of commonly shared
      property set definitions of a ramp and an optional set of
      product representations. It is used to define a ramp
      specification (i.e. the specific product information, that
      is common to all occurrences of that product type).
    </p>
    <blockquote>
      <small>NOTE The product representations are defined as
      representation maps (at the level of the supertype
      <i>IfcTypeProduct</i>, which gets assigned by an element
      occurrence instance through the
      <i>IfcShapeRepresentation.Item[1]</i> being an
      <i>IfcMappedItem</i>.</small>
    </blockquote>
    <p>
      An <i>IfcRampType</i>˙is used to define the common
      properties of a specific ramp that may be applied to many
      instances of that type to assign a specific style. 
      Building element types (or the instantiable subtypes) 
      may be exchanged without being
      already assigned to occurrences.
    </p>
    <p>
      The <i>IfcRampType</i> can have common material (using the
      inverse relationship <i>HasAssociations</i>) or property
      set information (using <i>HasPropertySets</i>) assigned. If
      present, it does apply equally to all occurrences of the
      <i>IfcRampType</i>. Property set information may be
      overridden at the occurrence.
    </p>
    <p>
      The occurrences of the <i>IfcRampType</i> are represented
      by instances of <i>IfcRamp</i>.
    </p>
    <blockquote>
      <small><font color=""#0000FF"">HISTORY New entity in Release
      IFC2x Edition 4.</font></small>
    </blockquote>
</EPM-HTML>"
1592;IfcRoofType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The element type
      <i>IfcRoofType</i> defines a list of commonly shared
      property set definitions of a roof and an optional set of
      product representations. It is used to define a roof
      specification (i.e. the specific product information, that
      is common to all occurrences of that product type).
    </p>
    <blockquote>
      <small>NOTE The product representations are defined as
      representation maps (at the level of the supertype
      <i>IfcTypeProduct</i>, which gets assigned by an element
      occurrence instance through the
      <i>IfcShapeRepresentation.Item[1]</i> being an
      <i>IfcMappedItem</i>.</small>
    </blockquote>
    <p>
      An <i>IfcRoofType</i>˙is used to define the common
      properties of a specific roof that may be applied to many
      instances of that type to assign a specific style. Building
      element types (or the instantiable subtypes) may be
      exchanged without being already assigned to occurrences.
    </p>
    <p>
      The <i>IfcRoofType</i> can have common material (using the
      inverse relationship <i>HasAssociations</i>) or property
      set information (using <i>HasPropertySets</i>) assigned. If
      present, it does apply equally to all occurrences of the
      <i>IfcRoofType</i>. Property set information may be
      overridden at the occurrence.
    </p>
    <p>
      The occurrences of the <i>IfcRoofType</i> are represented
      by instances of <i>IfcRoof</i>.
    </p>
    <blockquote>
      <small><font color=""#0000FF"">HISTORY New entity in Release
      IFC2x Edition 4.</font></small>
    </blockquote>
</EPM-HTML>"
1595;IfcChimneyType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>: The <i>IfcChimneyType</i>
      defines a list of commonly shared property set definitions
      of a chimney element and an optional set of product
      representations. It is used to define a chimney
      specification (i.e. the specific product information, that
      is common to all occurrences of that product type).
    </p>
    <blockquote>
      <small>NOTE: The product representations are defined as
      representation maps (at the level of the supertype
      <i>IfcTypeProduct</i>, which gets assigned by an element
      occurrence instance through the
      <i>IfcShapeRepresentation.Item[1]</i> being an
      <i>IfcMappedItem</i>.</small>
    </blockquote>
    <p>
      A chimney type is used to define the common properties of a
      certain type of chimney that may be applied to many
      instances of that type to assign a specific style. Chimney
      types may be exchanged without being already assigned to
      occurrences.
    </p>
    <p>
      The occurrences of the <i>IfcChimneyType</i> are
      represented by instances of <i>IfcChimney.</i>
    </p>
    <blockquote>
      <small><font color=""#0000FF"">HISTORY New entity in Release
      IFC2x4.</font></small>
    </blockquote>
</EPM-HTML>"
1598;IfcBuildingElementProxyType;"<EPM-HTML>
    <p>
      <u>Definition from IAI</u>:
      The˙<i>IfcBuildingElementProxyType</i> defines a list of
      commonly shared property set definitions of a building
      element proxy and an optional set of product
      representations. It is used to define an element
      specification (i.e. the specific product information, that
      is common to all occurrences of that product type).
    </p>
    <blockquote>
      <p>
        <small>NOTE˙ The product representations are defined as
        representation maps (at the level of the supertype
        <i>IfcTypeProduct</i>, which gets assigned by an element
        occurrence instance through the
        <i>IfcShapeRepresentation.Item[1]</i> being an
        <i>IfcMappedItem</i>.</small>
      </p>
    </blockquote>
    <p>
      A building element proxy type is used to define the common
      properties of a certain type of a building element proxy
      that may be applied to many instances of that˙type to
      assign a specific style. Building element proxy types˙may
      be exchanged without being already assigned to occurrences.
    </p>
		<blockquote>
		<p><small>NOTE  Although an building element proxy does not have
		a predefined ontological meaning the provision of a type may be
		helpful in sharing information among multiple occurrences. Applications 
		that provide type information for element types not yet included in the
		current IFC specification can use the <i>IfcBuildingElementProxyType</i>
		to exchange such types.</small></p>
		</blockquote>
    <p>
      The occurrences of the <i>IfcBuildingElementProxyType</i>
      are represented by instances of
      <i>IfcBuildingElementProxy</i>.
    </p>
    <blockquote>
      <p>
        <font color=""#0000FF""><small>HISTORY˙ New entity in
        Release IFC2x Edition 3.</small></font>
      </p>
    </blockquote>
</EPM-HTML>"
1600;IfcCoveringType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcCoveringType</i> defines commonly shared information for
occurrences of coverings. The set of shared information may
include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material (layer set) information</li>
<li>common shape representations</li>
</ul>
<p>It is used to define an covering specification or covering
style (i.e. the specific product information, that is common to
all occurrences of that product type). Covering types may be
exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcCoveringType</i> are represented
by instances of <i>IfcCovering</i></p>
<blockquote>
<p><small><font color=""#0000FF"">HISTORY New entity in Release
IFC2x Edition 2.</font></small></p>
</blockquote>
<p><u>Informal proposition</u></p>
<ol>
<li>The material assignment, if provided using the
<i>IfcRelAssociatesMaterial</i> relationship, shall not reference
the <i>IfcMaterialLayerSetUsage</i>.</li>
</ol>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcCoveringType</i> is defined by the
<i>IfcMaterialLayerSet</i> or as fall back by <i>IfcMaterial</i>
and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the
<i>IfcCoveringType</i> are defined by the <i>IfcPropertySet</i>
and are attached by the <i>HasPropertySets</i> attribute. The
following property set definitions specific to the
<i>IfcCoveringType</i> are part of this IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcCoveringType</i> and those that are only assignable to
<i>IfcCovering</i>. If the same property is assigned to the
<i>IfcCoveringType</i> and the <i>IfcCovering</i> being an
occurrence of the <i>IfcCoveringType</i>, then the occurrence
property overrides the type property.</small></blockquote>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CoveringCommon.xml"" target=
""SOURCE"">Pset_CoveringCommon</a>: common property set for all
covering types
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CoveringCeiling.xml""
target=""SOURCE"">Pset_CoveringCeiling</a>: specific property set
for all occurrences of covering types with the PredefinedType:
CEILING</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_CoveringFlooring.xml""
target=""SOURCE"">Pset_CoveringFlooring</a>: specific property set
for all occurrences of coverings with the PredefinedType:
FLOORING</li>
</ul>
</li>
</ul>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcCoveringType</i> may define the shared geometric
representation for all covering occurrences. The
<i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an <i>RepresentationIdentifier</i> 'Box', 'Surface', or 'Body').
(See geometric use definition of <i>IfcCovering</i> for further
information).</p>
<blockquote><small>NOTE If the <i>IfcCoveringType</i> has an
associated <i>IfcMaterialLayerSet</i>, then no shared geometric
representation shall be provided.</small></blockquote>
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcCoveringType</i>.</small></blockquote>
</EPM-HTML>"
1603;IfcDoorType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcDoorType</i> defines commonly shared information
for occurrences of doors. The set of shared information may
include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common operation type definitions</li>
<li>common shape representations</li>
</ul>
<p>A door type defines the particular parameter of the lining and
one (or several) panels through the
<i>IfcDoorLiningProperties</i> and the
<i>IfcDoorPanelProperties</i> as predefined property sets
applicable to doors only.</p>
<p>It is used to define a door specification, or door style (i.e.
the specific product information that is common to all
occurrences of that door type). Door types may be exchanged
without being already assigned to occurrences.</p>
<blockquote><small>NOTE The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>Occurrences of the <i>IfcDoorType</i> within building models
are represented by instances of <i>IfcDoor</i> or
<i>IfcDoorStandardCase</i>.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4 .</font></small><br>
<small><font color=""#FF0000"">NOTE The entity <i>IfcDoorType</i>
replaces the previous definition <i>IfcDoorStyle</i> (which is
deprecated in IFC2x4).</font></small></blockquote>
<p><u><b>Operation type use definition</b></u></p>
<p>The <i>IfcDoorTypeOperationEnum</i> defines the general layout
of the door type and its symbolic presentation. Depending on the
enumerator, the appropriate instances of
<i>IfcDoorLiningProperties</i> and <i>IfcDoorPanelProperties</i>
are attached in the list of <i>HasPropertySets</i>. The
<i>IfcDoorTypeOperationEnum</i> mainly determines the hinge side
(left hung, or right hung), the operation (swinging, sliding,
folding, etc.) and the number of panels.</p>
<blockquote><small>Note ˙There are different definitions in
various countries on what a left opening or left hung or left
swing door is (same for right). Therefore the IFC definition may
derivate from the local standard and may need to be mapped
appropriately.</small></blockquote>
<p>See geometry use definitions at
<i>IfcDoorTypeOperationEnum</i> for the correct usage of opening
symbols for different operation types.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcDoorType</i> is defined by the
<i>IfcMaterialConstituentSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p>The following keywords for
<i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i>
shall be used:</p>
<ul>
<li>'Lining' - to indicate that the material constituent applies
to to the door lining</li>
<li>'Framing' - to indicate that the material constituent applies
to to the door framing, if not provided, the 'Lining' material
information applied to frams as well</li>
<li>'Glazing' - to indicate that the material constituent applies
to to the glazing as well</li>
</ul>
<p>If the fall back single <i>IfcMaterial</i> is referenced, it
applies to the lining and framing of the door.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcDoorType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcDoorType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcDoorType</i> and those that are only assignable to
<i>IfcDoor</i>. If the same property is assigned to the
<i>IfcDoorType</i> and the <i>IfcDoor</i> being an occurrence of
the <i>IfcDoorType</i>, then the occurrence property overrides
the type property.</small></blockquote>
<ul>
<li><a href=""../../psd/IfcSharedBldgElements/Pset_DoorCommon.xml""
target=""SOURCE"">Pset_WallCommon</a>: common property set for all
door types.</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowGlazingType.xml""
target=""SOURCE"">Pset_DoorWindowGlazingType</a>: specific property
set for the glazing properties of the door type glazing</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowShadingType.xml""
target=""SOURCE"">Pset_DoorWindowShadingType</a>: specific property
set for the shading properties of the door type shading</li>
</ul>
<p>Two subtypes of <i>IfcPreDefinedPropertySet</i> are applicable
to <i>IfcDoorType</i>:</p>
<ul>
<li><i>IfcDoorLiningProperties</i> - a single instance to define
the shape parameters of the door lining</li>
<li><i>IfcDoorPanelProperties</i> - one or several instances to
define the shape parameters of the door panel(s)</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The <i>IfcDoorType</i> may define the common shape of door
occurrences. The common shape can be defined by</p>
<ul>
<li>applying shape parameters defined within the associated
<i>IfcDoorLiningProperties</i> and <i>IfcDoorPanelProperties</i>
applied to the 'Profile' geometric representation. It is only
applicable if the <i>IfcDoorType</i> has only occurrences of type
<i>IfcDoorStandardCase</i> (See geometric use definition of
<i>IfcDoorStandardCase</i> for further information).</li>
<li>applying the <i>RepresentationMaps</i> attribute to refer to
a list of <i>IfcRepresentationMap</i>'s, that allow for multiple
geometric representations (e.g. with
<i>IfcShapeRepresentation</i>'s having an
<i>RepresentationIdentifier</i> 'Box', 'Profile', 'FootPrint', or
'Body')
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcDoor</i> and
<i>IfcDoorStandardCase</i></small></blockquote>
</li>
</ul>
</EPM-HTML>"
1606;IfcWindowType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcWindowType</i> defines commonly shared information for
occurrences of windows. The set of shared information may
include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common partitioning of panels</li>
<li>common operation types of panels</li>
<li>common shape representations</li>
</ul>
<p>A window type defines the particular parameter of the lining
and one (or several) panels through the
<i>IfcWindowLiningProperties</i> and the
<i>IfcWindowPanelProperties</i> as predefined property sets
applicable to windows only.</p>
<p>It is used to define a window specification, or window style
(i.e. the specific product information that is common to all
occurrences of that window type). Window types may be exchanged
without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcWindowType</i> within building models
are represented by instances of <i>IfcWindow</i> or
<i>IfcWindowStandardCase</i>.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
IFC2x4 .</font></small><br>
<small><font color=""#FF0000"">NOTE The entity <i>IfcWindowType</i>
replaces the previous definition <i>IfcWindowStyle</i> (which is
deprecated in IFC2x4).</font></small></blockquote>
<p><u><b>Partitioning type use definition</b></u></p>
<p>The <i>IfcWindowTypePartitioningEnum</i> defines the general
layout of the window type and its symbolic presentation.
Depending on the enumerator, the appropriate instances of
<i>IfcWindowLiningProperties</i> and
<i>IfcWindowPanelProperties</i> are attached in the list of
<i>HasPropertySets</i>. The <i>IfcWindowTypePartitioningEnum</i>
mainly determines the way of partitioning the window into
individual window panels and thereby number and position of
window panels.</p>
<p>See geometry use definitions at
<i>IfcWindowTypePartitioningEnum</i> for the correct usage of
panel partitioning and <i>IfcWindowPanelProperties</i> for the
opening symbols for different panel operation types.</p>
<p><u><b>Material Use Definition</b></u></p>
<p>The material of the <i>IfcWindowType</i> is defined by the
<i>IfcMaterialConstituentSet</i> or as fall back by
<i>IfcMaterial</i> and attached by the
<i>IfcRelAssociatesMaterial</i><i>.RelatingMaterial</i>. It is
accessible by the inverse <i>HasAssociations</i>
relationship.</p>
<p>The following keywords for
<i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i>
shall be used:</p>
<ul>
<li>'Lining' - to indicate that the material constituent applies
to to the window lining</li>
<li>'Framing' - to indicate that the material constituent applies
to to the window panels, if not provided, the 'Lining' material
information applied to panels as well</li>
<li>'Glazing' - to indicate that the material constituent applies
to to the glazing part</li>
</ul>
<p>If the fall back single <i>IfcMaterial</i> is referenced, it
applies to the lining and framing of the window.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcWindowType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcWindowType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcWindowType</i> and those that are only assignable to
<i>IfcWindow</i>. If the same property is assigned to the
<i>IfcWindowType</i> and the <i>IfcWindow</i> being an occurrence
of the <i>IfcWindowType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_WindowCommon.xml"" target=
""SOURCE"">Pset_WindowCommon</a>: common property set for all
window types.</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowGlazingType.xml""
target=""SOURCE"">Pset_DoorWindowGlazingType</a>: specific property
set for the glazing properties of the door type glazing</li>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_DoorWindowShadingType.xml""
target=""SOURCE"">Pset_DoorWindowShadingType</a>: specific property
set for the shading properties of the door type shading</li>
</ul>
<p>Two subtypes of <i>IfcPreDefinedPropertySet</i> are applicable
to <i>IfcWindowType</i>:</p>
<ul>
<li><i>IfcWindowLiningProperties</i> - a single instance to
define the shape parameters of the window lining</li>
<li><i>IfcWindowPanelProperties</i> - one or several instances to
define the shape parameters of the window panel(s)</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The <i>IfcWindowType</i> may define the common shape of window
occurrences. The common shape can be defined by</p>
<ul>
<li>applying shape parameters defined within the associated
<i>IfcWindowLiningProperties</i> and
<i>IfcWindowPanelProperties</i> applied to the 'Profile'
geometric representation. It is only applicable if the
<i>IfcWindowType</i> has only occurrences of type
<i>IfcWindowStandardCase</i> (See geometric use definition of
<i>IfcWindowStandardCase</i> for further information).</li>
<li>applying the <i>RepresentationMaps</i> attribute to refer to
a list of <i>IfcRepresentationMap</i>'s, that allow for multiple
geometric representations (e.g. with
<i>IfcShapeRepresentation</i>'s having an
<i>RepresentationIdentifier</i> 'Box', 'Profile', 'FootPrint', or
'Body')
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcWindow</i> and
<i>IfcWindowStandardCase</i></small></blockquote>
</li>
</ul>
</EPM-HTML>"
1609;IfcShadingDeviceType;"<EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcShadingDeviceType</i>
defines a list of commonly shared property set definitions of a
shading device element and an optional set of product
representations. It is used to define a shading device
specification (i.e. the specific product information, that is
common to all occurrences of that product type).</p>
<blockquote><small>NOTE: The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>A shading device type is used to define the common properties
of a certain type of chimney that may be applied to many
instances of that type to assign a specific style. Shading device
types may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcShadingDeviceType</i> are
represented by instances of <i>IfcShadingDevice</i>.</p>
<blockquote><small><font color=""#0000FF"">HISTORY New entity in
Release IFC2x4.</font></small></blockquote>
</EPM-HTML>"
1611;IfcBuildingSystem;"<EPM-HTML>
<p><b><u>Definition from IAI</u></b>: A building system is a
group by which building elements are group according to a common
function within the building.</p>
<blockquote><small><font color=""#0000FF"">HISTORY: New entity in
IFC 2x4.</font></small></blockquote>
<p>The group <i>IfcBuildingSystem</i> defines the occurrence of a
specialized system for use within the context of a building and
finishing fabric. Important functionalities for the description
of a building system are derived from supertypes:</p>
<ul>
<li>From <i>IfcSystem</i> it inherits the ability to couple the
building system via <i>IfcRelServicesBuildings</i> to one or more
<i>IfcSpatialElement</i> subtypes as necessary.</li>
</ul>
<ul>
<li>From <i>IfcGroup</i> it inherits the inverse attribute
<i>IsGroupedBy</i>, pointing to the relationship class
<i>IfcRelAssignsToGroup</i>. This allows to group building
elements (instances of <i>IfcBuildingElement</i> subtypes,
<i>IfcFurnishingElement</i> subtype, <i>IfcElementAssembly</i>
and <i>IfcTransportElement</i>, ).</li>
</ul>
<ul>
<li>From <i>IfcObjectDefinition</i> it inherits the inverse
attribute <i>IsDecomposedBy</i> pointing to the relationship
class <i>IfcRelAggregates</i>. It provides the hierarchy between
the separate (partial) building systems.</li>
</ul>
<p><b><u>Property Set Use Definition</u></b>:</p>
<p>The property sets relating to this entity are defined by the
<i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to this entity are part of this
IFC release:</p>
<ul>
<li><a href=
""../../psd/IfcSharedBldgElements/Pset_BuildingSystemCommon.xml""
target=""SOURCE"">Pset_BuildingSystemCommon</a>: common property
set for building system occurrences</li>
</ul>

</EPM-HTML>"
1621;IfcAsset;"<EPM-HTML> 
 
<p>An asset is a uniquely identifiable grouping of elements acting as a single entity that has a financial value or that can be operated on as a single unit.</p> 
 
<p>An asset is generally the level of granularity at which maintenance operations are undertaken. An asset is a group that can contain one or more elements. Whilst the financial value of a component or element can be defined, financial value is also defined for accounting purposes at the level of the asset.<br/>  <br/>There are a number of actors that can be associated with an asset, each actor having a role. Actors within the scope of the project are indicated using the <a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a> relationship in which case roles should be defined through the <a href=""../../ifcactorresource/lexical/ifcactorrole.htm"">IfcActorRole</a> class; otherwise principal actors are identified as attributes of the class. In the existence of both, direct attributes take precedence.<br/>  <br/>There are a number of costs that can be associated with an asset, each cost having a role. These are specified through the <i>OriginalValue</i>, <i>CurrentValue</i>, <i>TotalReplacementCost</i> and <i>DepreciatedValue</i> attributes.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x.  In IFC2x4, all attributes made optional and date values changed to use <i>IfcDate</i>.<br/></font></blockquote>
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Refer to the documentation at the supertype <a href=""../../ifckernel/lexical/ifcgroup.htm"">IfcGroup</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_Asset.xml"" target=""SOURCE"">Pset_Asset</a></li> 
</ul> 
 
<p><b><u>Classification Use Definition</u></b></p> 
<p>Classifications may be applied using <a href=""../../ifckernel/lexical/ifcrelassociatesclassification.htm"">IfcRelAssociatesClassification</a> where <i>RelatedObjects</i> contains the  <b>IfcAsset</b> and <i>RelatingClassification</i> refers to an <a href=""../../ifcexternalreferenceresource/lexical/ifcclassification.htm"">IfcClassification</a> or <a href=""../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm"">IfcClassificationReference</a>.</p> 
<ul> 
<li><a href=""../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm"">IfcClassificationReference</a>: The operating function of an asset within an organization may be particularly valuable in situations where one organization provides and maintains core services and another organization adds and maintains terminal services. It can classify who owns and is responsible for the asset. Operating function can be designated through the use of one or more classification references.</li></li> 
</ul> 
<p><b><u>Assignment Use Definition</u></b></p> 
<p> The <b>IfcAsset</b> may be assigned to the following entities using relationships as indicated:</p> 
<ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a> (<a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a>): Indicates the actor who owns, uses, or is responsible for the asset (as indicated by role in relationship), if such actor is within the scope of the project.  </li> 
<li><a href=""../../ifcsharedmgmtelements/lexical/ifccostitem.htm"">IfcCostItem</a> (<a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a>): Indicates a cost item encompassing the asset.</li> 
</ul> 
<p> The <b>IfcAsset</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstogroup.htm"">IfcRelAssignsToGroup</a> relationship where <i>RelatingGroup</i> refers to the <b>IfcAsset</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a>: Physical elements that comprise the asset.
</li> 
</ul> 
 
</EPM-HTML>"
1631;IfcInventory;"<EPM-HTML> 
 
<p>An inventory is a list of items within an enterprise.</p> 
 
<p>Various types of inventory can be included. These are identified by the range of values within the inventory type enumeration which includes space, asset, and furniture. User defined inventories can also be defined for lists of particular types of element such as may be required in operating and maintenance instructions. Such inventories should be constrained to contain a list of elements of a restricted type.<br/><br/>There are a number of actors that can be associated with an inventory, each actor having a role. Actors within the scope of the project are indicated using the <a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a> relationship in which case roles should be defined through the <a href=""../../ifcactorresource/lexical/ifcactorrole.htm"">IfcActorRole</a> class; otherwise principal actors are identified as attributes of the class. In the existence of both, direct attributes take precedence.<br/><br/>There are a number of costs that can be associated with an inventory, each cost having a role. These are specified through the <i>CurrentValue</i> and <i>OriginalValue</i> attributes.</p

><blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2.0.  Modified in IFC2x4 to make all attributes optional and remove Where Rule.<br></font></blockquote> 
 
<p><b><u>Assignment Use Definition</u></b></p> 
<p> The <b>IfcInventory</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstogroup.htm"">IfcRelAssignsToGroup</a> relationship where <i>RelatingGroup</i> refers to the <b>IfcInventory</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifcsharedfacilitieselements/lexical/ifcasset.htm"">IfcAsset</a>: Assets included in the inventory.
</li> 
<li><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a>: Elements such as furniture included in the inventory.
</li> 
<li><a href=""../../ifcproductextension/lexical/ifcspace.htm"">IfcSpace</a>: Spaces included in the inventory.
</li> 
</ul> 
 
</EPM-HTML>"
1644;IfcOccupant;"<EPM-HTML> 
 
<p>An occupant is a type of actor that defines the form of occupancy of a property.</p> 
 
<p>The principal purpose of <b>IfcOccupant</b> is to determine the nature of occupancy of a property for a particular actor. All characteristics relating to the actor (name and organization details) are inherited from the <a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a> class.</p

><blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x<br></font></blockquote> 
 
<p><b><u>Assignment Use Definition</u></b></p> 
<p> The <b>IfcOccupant</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a> relationship where <i>RelatingActor</i> refers to the <b>IfcOccupant</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifcproductextension/lexical/ifcspatialstructureelement.htm"">IfcSpatialStructureElement</a>: Indicates the property to be occupied. Particular details of the agreement relating to the occupancy of a property are dealt within the <i>Pset_PropertyAgreement</i> that is defined for the instance of <i>IfcSpatialStructureElement</i>. This means that an occupant may be related to a site, building, building storey or space through the <i>IfcSpatialStructureElement.ElementComposition</i> attribute. For instance, if the property concerned is several office spaces on a building storey, it might be appropriate to reference <i>IfcBuildingStorey.ElementComposition=PARTIAL</i>.  Occupants of a property may be considered to be the parties to an agreement. The roles that the occupant may play in respect to an agreement are defined in the <i>IfcOccupantTypeEnum</i> enumeration. If the role is not specified by the predefined contents of this enumeration, the value <i>USERDEFINED</i> may be set and the <i>ObjectType</i> attribute asserted.
</li> 
</ul> 
 
</EPM-HTML>"
1657;IfcSystemFurnitureElement;"<EPM-HTML> 
 
<p>A system furniture element defines components of modular furniture which are not directly placed in a building structure but aggregated inside furniture.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Type Use Definition</u></b></p> 
<p><b>IfcSystemFurnitureElement</b> defines the occurrence of any furniture element; common information about furniture element types is handled by <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a>.  The <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, composition, assignments, and representations.  The <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a> is attached using the <a href=""../../ifckernel/lexical/ifcreldefinesbytype.htm"">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute.  If the <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a> has aggregated elements, such objects are reflected at the <b>IfcSystemFurnitureElement</b> occurrence using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.</p> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Property sets may also be specified at the <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a>, defining the common property data for all occurrences of the same type.  They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcSystemFurnitureElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcSystemFurnitureElement</b> override the properties defined at <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a>.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcfurnishingelement.htm"">IfcFurnishingElement</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_SystemFurnitureElementTypeCommon.xml"" target=""SOURCE"">Pset_SystemFurnitureElementTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_SystemFurnitureElementTypePanel.xml"" target=""SOURCE"">Pset_SystemFurnitureElementTypePanel</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtypeenum.htm"">PANEL</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_SystemFurnitureElementTypeWorkSurface.xml"" target=""SOURCE"">Pset_SystemFurnitureElementTypeWorkSurface</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtypeenum.htm"">WORKSURFACE</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSystemFurnitureElement</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  Material information can also be given at the <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtype.htm"">IfcSystemFurnitureElementType</a>, defining the common attribute data for all occurrences of the same type.  The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Finish'</b>: The finish, typically at visible aspects of the furniture.</li> 
<li><b>'Frame'</b>: The frame from which the object is constructed.</li> 
<li><b>'Hardware'</b>: Finish hardware such as knobs or handles.</li> 
<li><b>'Padding'</b>: Padding such as cushions.</li> 
<li><b>'Panel'</b>: Panels such as glass.</li> 
</ul> 
 
</EPM-HTML>"
1666;IfcFurniture;"<EPM-HTML> 
 
<p>Furniture defines complete furnishings such as a table, desk, chair, or cabinet, which may or may not be permanently attached to a building structure.</p> 
 
<p>Occurrences of furniture that are built in (where the property <i>Pset_FurnitureTypeCommon.IsBuiltIn</i> is asserted to be TRUE) should have their connection relationship with a building element occurrence defined through the <a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a> relationship.</p

><blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Type Use Definition</u></b></p> 
<p><b>IfcFurniture</b> defines the occurrence of any furniture; common information about furniture types is handled by <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a>.  The <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, composition, assignments, and representations.  The <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a> is attached using the <a href=""../../ifckernel/lexical/ifcreldefinesbytype.htm"">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute.  If the <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a> has aggregated elements, such objects are reflected at the <b>IfcFurniture</b> occurrence using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.</p> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Property sets may also be specified at the <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a>, defining the common property data for all occurrences of the same type.  They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcFurnitureType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcFurniture</b> override the properties defined at <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a>.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcfurnishingelement.htm"">IfcFurnishingElement</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeCommon.xml"" target=""SOURCE"">Pset_FurnitureTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeChair.xml"" target=""SOURCE"">Pset_FurnitureTypeChair</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">CHAIR</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeDesk.xml"" target=""SOURCE"">Pset_FurnitureTypeDesk</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">DESK</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeFileCabinet.xml"" target=""SOURCE"">Pset_FurnitureTypeFileCabinet</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">FILECABINET</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeTable.xml"" target=""SOURCE"">Pset_FurnitureTypeTable</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">TABLE</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFurniture</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  Material information can also be given at the <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretype.htm"">IfcFurnitureType</a>, defining the common attribute data for all occurrences of the same type.  The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Finish'</b>: The finish, typically at visible aspects of the furniture.</li> 
<li><b>'Frame'</b>: The frame from which the object is constructed.</li> 
<li><b>'Hardware'</b>: Finish hardware such as knobs or handles.</li> 
<li><b>'Padding'</b>: Padding such as cushions.</li> 
<li><b>'Panel'</b>: Panels such as glass.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcFurniture</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcFurniture</b> and <i>RelatedObjects</i> contains one or more components.  Composition use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelement.htm"">IfcSystemFurnitureElement</a> components.  Modular furniture may be aggregated into components.</ul> 
 
</EPM-HTML>"
1680;IfcSystemFurnitureElementType;"<EPM-HTML> 
 
<p>The furnishing element type <b>IfcSystemFurnitureElementType</b> defines commonly shared information for occurrences of furniture elements.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a furniture element specification (i.e. the specific product information, that is common to all occurrences of that product type).  Furniture Element types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcSystemFurnitureElementType</b> are represented by instances of <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelement.htm"">IfcSystemFurnitureElement</a>.</p> 
</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcfurnishingelementtype.htm"">IfcFurnishingElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_SystemFurnitureElementTypeCommon.xml"" target=""SOURCE"">Pset_SystemFurnitureElementTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_SystemFurnitureElementTypePanel.xml"" target=""SOURCE"">Pset_SystemFurnitureElementTypePanel</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtypeenum.htm"">PANEL</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_SystemFurnitureElementTypeWorkSurface.xml"" target=""SOURCE"">Pset_SystemFurnitureElementTypeWorkSurface</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelementtypeenum.htm"">WORKSURFACE</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSystemFurnitureElementType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Finish'</b>: The finish, typically at visible aspects of the furniture.</li> 
<li><b>'Frame'</b>: The frame from which the object is constructed.</li> 
<li><b>'Hardware'</b>: Finish hardware such as knobs or handles.</li> 
<li><b>'Padding'</b>: Padding such as cushions.</li> 
<li><b>'Panel'</b>: Panels such as glass.</li> 
</ul> 
 
</EPM-HTML>"
1683;IfcFurnitureType;"<EPM-HTML> 
 
<p>The furnishing element type <b>IfcFurnitureType</b> defines commonly shared information for occurrences of furnitures.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a furniture specification (i.e. the specific product information, that is common to all occurrences of that product type).  Furniture types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcFurnitureType</b> are represented by instances of <a href=""../../ifcsharedfacilitieselements/lexical/ifcfurniture.htm"">IfcFurniture</a>.</p> 
</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcproductextension/lexical/ifcfurnishingelementtype.htm"">IfcFurnishingElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeCommon.xml"" target=""SOURCE"">Pset_FurnitureTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeChair.xml"" target=""SOURCE"">Pset_FurnitureTypeChair</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">CHAIR</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeDesk.xml"" target=""SOURCE"">Pset_FurnitureTypeDesk</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">DESK</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeFileCabinet.xml"" target=""SOURCE"">Pset_FurnitureTypeFileCabinet</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">FILECABINET</a>)</li> 
<li><a href=""../../psd/IfcSharedFacilitiesElements/Pset_FurnitureTypeTable.xml"" target=""SOURCE"">Pset_FurnitureTypeTable</a> (<a href=""../../ifcsharedfacilitieselements/lexical/ifcfurnituretypeenum.htm"">TABLE</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFurnitureType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Finish'</b>: The finish, typically at visible aspects of the furniture.</li> 
<li><b>'Frame'</b>: The frame from which the object is constructed.</li> 
<li><b>'Hardware'</b>: Finish hardware such as knobs or handles.</li> 
<li><b>'Padding'</b>: Padding such as cushions.</li> 
<li><b>'Panel'</b>: Panels such as glass.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcFurnitureType</b> may be decomposed into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcFurnitureType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Composition use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelement.htm"">IfcSystemFurnitureElement</a> components.  Modular furniture may be aggregated into components.</ul> 
 
</EPM-HTML>"
1688;IfcDoorStyle;"<EPM-HTML>

<p>Definition: The door style, <i>IfcDoorStyle</i>, defines a particular style of doors, which may be included into the spatial context of the building model through instances of <i>IfcDoor</i>. A door style defines the overall parameter of the door style and refers to the particular parameter of the lining and one (or several) panels through the <i>IfcDoorLiningProperties</i> and the <i>IfcDoorPanelProperties</i>.</p>

<p>The door entity, <i>IfcDoor</i>, defines a particular occurrence of a door inserted in the spatial context of a
project. The actual parameter of the door and/or its shape is defined at the <i>IfcDoorStyle</i>, to which the <i>IfcDoor</i>
is related by the inverse relationship <i>IsDefinedBy</i> pointing to <i>IfcRelDefinedByType</i>. The <i>IfcDoorStyle</i>
also defines the particular attributes for the lining<i>, IfcDoorLiningProperties</i>, and panels, <i>IfcDoorPanelProperties</i>.</p>

<blockquote class=""history"">
HISTORY˙New entity in IFC Release 2x.
</blockquote>
<blockquote class=""deprecate"">
IFC2x4 CHANGE The entity is deprecated and shall not be used. The new entity
<i>IfcDoorType</i> shall be used instead.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>

<p>The <i>IfcDoorStyle</i> defines the baseline geometry, or the representation map, for all occurrences of the door style, given
by the <i>IfcDoor</i>, pointing to this style. The representation of the door style may be given by the agreed set of minimal
parameters, defined for the door lining and the door panel(s), or it may be given by a geometric representation used by the
<i>IfcRepresentationMap</i>. The attribute <i>ParameterTakesPrecedence</i> decides, whether the set of parameters can be used to exactly represent the shape of the door style (TRUE), or whether the attached <i>IfcRepresentationMap</i>
holds the exact representation (FALSE).</p>

<p>The <i>IfcDoorStyleOperationTypeEnum</i> defines the general layout of the door style. Depending on the enumerator, the
appropriate instances of <i>IfcDoorLiningProperties</i> and <i>IfcDoorPanelProperties</i> are attached in the list of
<i>HasPropertySets</i>. The <i>IfcDoorStyleOperationTypeEnum</i> mainly determines the hinge side (left hung, or right hung), the
operation (swinging, sliding, folding, etc.)˙and the number of panels.</p>

<p>See geometry use definitions at <i>IfcDoorStyleOperationTypeEnum</i> for the correct usage of opening symbols for different operation types.</p>

</EPM-HTML>"
1722;IfcWindowStyle;"<EPM-HTML>

<p>Definition: The window style defines a particular style of windows, which may be included into the spatial context of the building model through instances of <i>IfcWindow</i>. A window style defines the overall parameter of the window style and refers to the particular parameter of the lining and one (or several) panels through <i>IfcWindowLiningProperties</i> and <i>IfcWindowPanelProperties</i>.</p>

<p>The window entity (<i>IfcWindow</i>) defines a particular occurrence of a window inserted in the spatial context of a project. The actual parameter of the window and/or its shape is defined at the <i>IfcWindowStyle</i>, to which the <i>IfcWindow</i> related by the inverse relationship <i>IsDefinedBy</i> pointing to <i>IfcRelDefinesByType</i>. The <i>IfcWindowStyle</i> also defines the particular attributes for the lining (<i>IfcWindowLiningProperties</i>) and panels (<i>IfcWindowPanelProperties</i>).</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>
<blockquote class=""deprecated"">
IFC2x4 CHANGE The entity has been deprecated and shall not be used. The new entity <i>IfcWindowType</i> shall be used instead.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The <i>IfcWindowStyle</i> defines the baseline geometry, or the representation map, for all occurrences of the window style,
given by the IfcWindow, pointing to this style. The representation of the window style may be given by the agreed set
of minimal parameters, defined for the window lining and the window panel(s), or it may be given by a geometric representation
used by the <i>IfcRepresentationMap</i>. The attribute <i>ParameterTakesPrecedence</i> decides, whether the set of
parameters can be used to exactly represent the shape of the window style (TRUE), or whether the attached <i>IfcRepresentationMap</i> holds the exact representation (FALSE).</p>

<p>The <i>IfcWindowStyleOperationTypeEnum</i> defines the general layout of the window style. Depending on the enumerator, the
appropriate instances of <i>IfcWindowLiningProperties</i> and <i>IfcWindowPanelProperties</i> are attached in the list of
<i>HasPropertySets</i>. See geometry use definitions there.</p>

</EPM-HTML>"
1748;IfcDoorLiningProperties;"<EPM-HTML> 
<p>The door lining is the frame which
enables the door leaf to be fixed in position. The door lining is
used to hang the door leaf. The parameters of the door lining
(<i>IfcDoorLiningProperties</i>) define the geometrically
relevant parameter of the lining.</p>

<blockquote class=""note"">
NOTE˙ The <i>IfcDoorLiningProperties</i>
shall only be applied to construct the 3D shape of a door, if the
attribute <i>IfcDoorStyle.ParameterTakesPrecedence</i> is set
TRUE.</small>
</blockquote>

<p>The <i>IfcDoorLiningProperties</i> are included in the list of
properties of <i>IfcDoorStyle.HasPropertySets</i>. More
information about the door lining can be included in the same
list of the <i>IfcDoorStyle</i> using another
<i>IfcPropertySet</i> for dynamic extensions.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2.0. Has been renamed from <i>IfcDoorLining</i> in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE˙ The following attributes have been added <i>LiningToPanelOffsetX</i>, <i>LiningToPanelOffsetY</i>. The attribute <i>ShapeAspectStyle</i> is deprecated and shall no longer be used. Supertype changed to new <i>IfcPreDefinedPropertySet</i>.
</blockquote>

<p class=""use-head"">Geometry use definitions</p>
<p>The <i>IfcDoorLiningProperties</i> does not hold its own
geometric representation. However it defines parameters which can
be used to create the shape of the door style (which is inserted
by the <i>IfcDoor</i> into the spatial context of the
project) as shown in Figure 172.</p>
<p>The parameters of the <i>IfcDoorLiningProperties</i> define a
standard door lining, including (if given) a threshold and a
transom. The outer boundary of the lining is determined by the
occurrence parameter assigned to the <i>IfcDoor</i>, which
inserts the <i>IfcDoorStyle</i>.</p>


<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorLiningProperties-Fig01.png"" alt=""lining 1""
border=""0"" height=""250"" width=""280""></td>
<td align=""left"" valign=""top"">The lining is applied to the left,
right and upper side of the opening reveal. The parameters are:
<ul>
<li><i>LiningDepth</i>, <span class=""change"">if omited, equal to
wall thickness - this only takes effect if a value for
<i>LiningThickness</i> is given. If both parameters are not
given, then there is no lining.</span></li>
<li><i>LiningThickness</i></li>
<li><font color=""#0000FF""><i>LiningToPanelOffsetX</i></font></li>
<li><font color=""#0000FF""><i>LiningToPanelOffsetY</i></font></li>
<li style=""list-style-type:none"">
<blockquote class=""history"">NOTE Parameters added in
IFC2x4.</blockquote>
</li>
</ul>
</td>
</tr>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorLiningProperties-Fig02.png"" alt=""lining 2""
border=""0"" height=""250"" width=""280""></td>
<td align=""left"" valign=""top"">The lining can only cover part of
the opening reveal.
<ul>
<li><i>LiningOffset</i> : given if lining edge has an offset to
the x axis of the local placement.</li>
</ul>
<blockquote><small>NOTE ˙In addition to the˙<i>LiningOffset</i>,
the local placement of the <i>IfcDoor</i> can already have an
offset to the wall edge and thereby shift the lining along the y
axis. The actual position of the lining is calculated from the
origin of the local placement along the positive y axis with the
distance given by <i>LiningOffset</i>.</small></blockquote>
</td>
</tr>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorLiningProperties-Fig03.png"" alt=""lining 3""
border=""0"" height=""250"" width=""280""></td>
<td align=""left"" valign=""top"">The lining may include a casing,
which covers part of the wall faces around the opening. The
casing covers the left, right and upper side of the lining on
both sides of the wall. The parameters are:
<ul>
<li><i>CasingDepth</i></li>
<li><i>CasingThickness</i></li>
</ul>
</td>
</tr>
<tr>
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorLiningProperties-Fig04.png"" alt=""lining 4""
border=""0"" height=""250"" width=""250""></td>
<td align=""left"" valign=""top"">The lining may include a threshold,
which covers the bottom side of the opening. The parameters are:
<ul>
<li><i>ThresholdDepth</i>
<span class=""change"">if omited, equal to wall thickness - this
only takes effect if a value for <i>ThresholdThickness</i> is
given. If both parameters are not given, then there is no
threshold.</span></li>
<li><i>ThresholdThickness</i></li>
<li><i>ThresholdOffset</i> (not shown in figure): given, if the
threshold edge has an offset to the x axis of the local
placement.</li>
</ul>
</td>
</tr>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorLiningProperties-Fig05.png"" alt=""lining 5""
border=""0"" height=""300"" width=""250""></td>
<td align=""left"" valign=""top"">The lining may have a transom which
separates the door panel from a window panel. The transom, if
given, is defined by:
<ul>
<li><i>TransomOffset</i> : a parallel edge to the x axis of the
local placement</li>
<li><i>TransomThickness</i></li>
</ul>
<p>The depth of the transom is identical to the depth of the
lining and not given as separate parameter.</p>
</td>
</tr>
</tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 172 &mdash; Door lining properties</p></td></tr>
</table>

<blockquote class=""note"">NOTE <i>LiningDepth</i> describes the length of the lining along the reveal of the door opening. It can be given by an absolute value if the door lining has a specific depth depending on the door style. However often it is equal to the wall thickness. If the same door style is used (like the same type of single swing door), but inserted into different walls with different thicknesses, it would be necessary to create a special door style for each wall thickness. Therefore several CAD systems allow to set the value to ""automatically aligned"" to wall thickness. This should be exchanged by leaving the optional attribute LiningDepth unassigned. The same agreement applies to <i>ThresholdDepth</i>.
</blockquote>

</EPM-HTML>"
1767;IfcDoorPanelProperties;"<EPM-HTML> 
<p>A door panel is normally a door leaf that opens to allow people or
goods to pass. The parameters of the door panel define the
geometrically relevant parameter of the panel,</p>

<p>The <i>IfcDoorPanelProperties</i> are used to parametrically
describe the shape and operation of door panels. The parametric
definition can be added solely or additionally to the explicit
shape representation of the door.</p>

<p>The <i>IfcDoorStyle</i> can define doors consisting of more
then one panel. In this case, one instance of
<i>IfcDoorPanelProperties</i> has to be included for each door
panel. The <i>PanelPosition</i> attribute, in conjunction with
the <i>IfcDoorStyle.OperationType</i> attribute, determines to
which panel the <i>IfcDoorPanelProperties</i> apply.</p>
<p>The <i>IfcDoorPanelProperties</i> are included in the list of
properties , given by attribute <i>HasPropertySets</i> of the
<i>IfcDoorStyle</i>. More information about the door panel can be
included in the same list of the <i>IfcDoorStyle</i> using the
<i>IfcPropertySet</i> for dynamic extensions.</p>

<blockquote class=""history"">
HISTORY˙ New Entity in IFC Release 2.0.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Supertype changed to new <i>IfcPreDefinedPropertySet</i>.
</blockquote>

<p class=""use-head"">Geometry use definitions</p>

<p>The <i>IfcDoorPanelProperties</i> does not hold a geometric representation. However it defines parameters which can be used to create the shape of the door style (which is inserted by the <i>IfcDoor</i> into the spatial context of the project) as shown in Figure 173.</p>
<p>The parameters of the <i>IfcDoorPanelProperties</i> define a standard door panel, including (if given) a proportional width to define non-uniform double swing (or sliding, or folding) doors. The outer boundary of the panel is determined by the occurrence parameter assigned to the <i>IfcDoor</i>, which inserts the <i>IfcDoorStyle</i>. It has to take the lining parameter into account as well.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorPanelProperties-Fig01.gif"" alt=""panel 1"" border=
""0"" height=""187"" width=""266""></td>
<td align=""left"" valign=""top"">The depth of the panel (swinging,
double-acting, and sliding panels) is defined by the
<i>PanelDepth</i> parameter.
<ul>
<li><i>PanelDepth</i></li>
</ul>
</td>
</tr>
<tr valign=""top"">
<td align=""left"" valign=""top""><img src=
""figures/IfcDoorPanelProperties-Fig02.gif"" alt=""panel 2"" border=
""0"" height=""259"" width=""304""></td>
<td align=""left"" valign=""top"">For door operation types that
include more than one panel, the width of (at least) one panel is
given by a normalised ratio measure. It determines the width of
that panel, which is defined as a ratio of the overall width of
the door opening.
<ul>
<li><i>PanelWidth</i></li>
</ul>
</td>
</tr>
</tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 173 &mdash; Door panel properties</p></td></tr>
</table>

</EPM-HTML>"
1789;IfcWindowPanelProperties;"<EPM-HTML> 
<p>A window panel is a casement, that is, a component, fixed or opening,
consisting essentially of a frame and the infilling. The
infilling of a window panel is normally glazing. The way of
operation is defined in the operation type.</p>
<p>The <i>IfcWindowPanelProperties</i> are used to parametrically
describe the shape and operation of window panels. The parametric
definition can be added solely or additionally to the explicit
shape representation of the window.</p>
<p>The <i>IfcWindowStyle</i> can define windows consisting of
more then one panel. In this case, one instance of
<i>IfcWindowPanelProperties</i> has to be included for each
window panel. The <i>PanelPosition</i> attribute, in conjunction
with the <i>IfcWindowStyle.OperationType</i> attribute,
determines to which panel the <i>IfcWindowPanelProperties</i>
apply.</p>
<p>The <i>IfcWindowPanelProperties</i> are included in the list
of properties (<i>HasPropertySets</i>) of the
<i>IfcWindowStyle</i>. More information about the window panel
can be included in the same list of the <i>IfcWindowStyle</i>
using the <i>IfcPropertySet</i> for dynamic extensions.</p>
<blockquote class=""history"">
HISTORY New entity in
IFC Release 2.0, it had been renamed from IfcWindowPanel in IFC
Release 2x.</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Supertype changed to
new <i>IfcPreDefinedPropertySet</i>.
</blockquote>

<p class=""head=use"">Geometry use definitions</p>
<p>The <i>IfcWindowPanelProperties</i> does not hold an own
geometric representation. However it defines parameter, which can
be used to create the shape of the <i>IfcWindowStyle</i> (which
is inserted by the <i>IfcWindow</i> into the spatial context of
the project).</p>
<p>The parameters at the <i>IfcWindowPanelProperties</i> define a
standard window panel. The outer boundary of the panel is
determined by the occurrence parameter assigned to the IfcWindow,
which inserts the IfcWindowStyle. It has to take the lining
parameter into account as well. The position of the window panel
within the overall window is determined by the
<i>PanelPosition</i> attribute.</p>

<p>As shown in Figure 176, the panel is applied to the position within the lining as defined by the panel position attribute. The following parameter apply to that panel: <i>FrameDepth</i>, <i>FrameThickness</i>.</p>

<table>
<tr><td><img src=""figures/IfcWindowPanelProperties-Fig01.gif"" alt=""panel 1"" width=""239"" height=""129"" border=""0""></td>
<td valign=""top"" align=""left""></td></tr>
<tr><td><p class=""figure"">Figure 176 &mdash; Window panel properties</p></td></tr>
</table>

</EPM-HTML>"
1817;IfcWindowLiningProperties;"<EPM-HTML> 
<p>The window lining is the outer
frame which enables the window to be fixed in position. The
window lining is used to hold the window panels or other
casements. The parameter of the <i>IfcWindowLiningProperties</i>
define the geometrically relevant parameter of the lining.</p>

<blockquote class=""note"">
NOTE˙ The <i>IfcWindowLiningProperties</i>
shall only be applied to construct the 3D shape of a window, if
the attribute <i>IfcWindowStyle.ParameterTakesPrecedence</i> is
set TRUE.
</blockquote>

<p>The <i>IfcWindowLiningProperties</i> are included in the set
of properties of <i>IfcWindowStyle.HasPropertySets</i>. More
information about the window lining can be included in the same
set of the <i>IfcWindowStyle</i> using another
<i>IfcPropertySet</i> for dynamic extensions.</p>

<blockquote class=""history"">
HISTORY New Entity in IFC Release 2.0. Has been renamed from <i>IfcWindowLining</i> in
IFC Release 2x.</font></small>
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE˙ The following attributes have been added <i>LiningOffset</i>,
<i>LiningToPanelOffsetX</i>, <i>LiningToPanelOffsetY</i>. The
attribute <i>ShapeAspectStyle</i> is deprecated and shall no
longer be used. Supertype changed to new
<i>IfcPreDefinedPropertySet</i>.</font></small></blockquote>

<p class=""use-head"">Geometry use definitions</p>
<p>The <i>IfcWindowLiningProperties</i> does not hold a geometric representation. However it defines parameters which can be used to create the shape of the window style (which is inserted by the <i>IfcWindow</i> into the spatial context of the project) as shown in Figure 175.</p>
<p>The parameters at the <i>IfcWindowLiningProperties</i> define a standard window lining, including (if given) a mullion and a transom (for horizontal and vertical splits). The outer boundary of the lining is determined by the occurrence parameter assigned to the <i>IfcWindow</i>, which inserts the <i>IfcWindowStyle</i>.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"">
<tr>
<td><img src=""figures/IfcWindowLiningProperties-Fig05.png"" alt=
""lining 5"" width=""280"" height=""250"" border=""0""></td>
<td valign=""top"" align=""left"">The lining is applied to all faces
of the opening reveal. The parameter are:
<ul>
<li><i>LiningDepth</i></li>
<li><i>LiningThickness</i></li>
<li><font color=""#0000FF""><i>LiningOffset</i></font></li>
<li><font color=""#0000FF""><i>LiningToPanelOffsetX</i></font></li>
<li><font color=""#0000FF""><i>LiningToPanelOffsetY</i></font></li>
<li style=""list-style-type:none"">
<blockquote class=""change-ifc2x4>NOTE Parameters added in
IFC2x4.</blockquote>
</li>
</ul>
Inner side is defined as the direction of the window panel
opening operation.</td>
</tr>
<tr>
<td><img src=""figures/IfcWindowLiningProperties-Fig01.png"" alt=
""lining 1"" width=""250"" height=""200"" border=""0""></td>
<td valign=""top"" align=""left"">If the <i>OperationType</i> of the
window style is
<ul>
<li>DoublePanelVertical (shown)</li>
<li>TriplePanelBottom</li>
<li>TriplePanelTop</li>
<li>TriplePanelLeft</li>
<li>TriplePanelRight</li>
</ul>
the following additional parameter apply:
<ul>
<li><i>MullionThickness</i></li>
<li><i>FirstMullionOffset</i> - measured as offset to the Z axis
(in XZ plane)</li>
</ul>
</td>
</tr>
<tr>
<td><img src=""figures/IfcWindowLiningProperties-Fig02.png"" alt=
""lining 2"" width=""250"" height=""200"" border=""0""></td>
<td valign=""top"" align=""left"">If the <i>OperationType</i> of the
window style is
<ul>
<li>DoublePanelHorizontal</li>
<li>TriplePanelBottom</li>
<li>TriplePanelTop</li>
<li>TriplePanelLeft</li>
<li>TriplePanelRight</li>
</ul>
the following additional parameter apply
<ul>
<li><i>TransomThickness</i></li>
<li><i>FirstTransomOffset</i> measured as offset to the X axis
(in XZ plane)</li>
</ul>
</td>
</tr>
<tr>
<td><img src=""figures/IfcWindowLiningProperties-Fig03.png"" alt=
""lining 3"" width=""280"" height=""200"" border=""0""></td>
<td valign=""top"" align=""left"">If the <i>OperationType</i> of the
window style is
<ul>
<li><i>TriplePanelVertical</i></li>
</ul>
the following additional parameter apply
<ul>
<li><i>SecondMullionOffset</i></li>
</ul>
</td>
</tr>
<tr>
<td><img src=""figures/IfcWindowLiningProperties-Fig04.png"" alt=
""lining 4"" width=""250"" height=""250"" border=""0""></td>
<td valign=""top"" align=""left"">If the <i>OperationType</i> of the
window style is
<ul>
<li><i>TriplePanelHorizontal</i></li>
</ul>
the following additional parameter apply
<ul>
<li><i>SecondTransomOffset</i></li>
</ul>
</td>
</tr>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 175 &mdash; Window lining properties</p></td></tr>
</table>

<p>NOTE</p>
<ol>
<li>All offsets are given as a normalized ratio measure.</li>
</ol>

</EPM-HTML>"
1834;IfcPermeableCoveringProperties;"<EPM-HTML>

<p>This entity is a description of a panel within a
door or window (as fillers for opening) which allows for air
flow. It is given by its properties
(<i>IfcPermeableCoveringProperties</i>). A permeable covering is
a casement, such as a component, fixed or opening, consisting
essentially of a frame and the infilling. The infilling is
normally a grill, a louver or a screen. The way of operation is
defined in the operation type.</p>
<p>The <i>IfcPermeableCoveringProperties</i> are included in the
list of properties (<i>HasPropertySets</i>) of the
<i>IfcWindowStyle</i> or the <i>IfcDoorStyle</i>. More
information about the permeable covering can be included in the
same list of the window or door style using the
<i>IfcPropertySet</i> for dynamic extensions. This particularly
applies for additional properties for the various operation
types</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2.0, it had been renamed from
<i>IfcPermeableCovering</i> in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Supertype changed to new <i>IfcPreDefinedPropertySet</i>.
</blockquote>

<p class=""use-head"">Geometry use definitions</p>
<p>The <i>IfcPermeableCoveringProperties</i> does not hold a geometric representation. However it defines parameters which can be used to create the shape of the <i>IfcWindowStyle</i> (which is inserted by the <i>IfcWindow</i> into the spatial context of the project), or of the <i>IfcDoorStyle</i> (which is inserted by the <i>IfcDoor</i>).</p>
<p>The parameters at the <i>IfcPermeableCoveringProperties</i> define a standard permeable covering. The outer boundary of the panel is determined by the occurrence parameter assigned to the
<i>IfcWindow</i> or <i>IfcDoor</i>. It has to take the lining parameter into account as well. The position of the permeable covering within the overall window or door is determined by the
<i>PanelPosition</i> attribute.</p>


<p>As shown in Figure 174, the panel is applied to the position within the lining, as defined by the panel position attribute. The following parameters apply to that panel: <i>FrameDepth</i>, <i>FrameThickness</i>.</p>

<table>
<tr><td><img src=""figures/IfcPermeableCoveringProperties.gif"" alt=
""covering"" width=""400"" height=""215"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 174 &mdash; Permeable covering properties</p></td></tr>
</table>

</EPM-HTML>"
1847;IfcFlowInstrument;"<p>A flow instrument reads and displays the value of a particular property of a system at a point, or displays the difference in the value of a property between two points.</p>
              <p>Instrumentation is typically for the purpose of determining the value of the property at a point in time. It is not the purpose of an instrument to record or integrate the values over time (although they may be connected to recording devices that do perform such a function). This entity provides for all forms of mechanical flow instrument (thermometers, pressure gauges etc.) and electrical flow instruments (ammeters, voltmeters etc.)</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcFlowInstrument</b> defines the occurrence of any flow instrument; common information about flow instrument types is handled by <i>IfcFlowInstrumentType</i>. 
The <i>IfcFlowInstrumentType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcFlowInstrumentType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcFlowInstrumentType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcFlowInstrument</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcFlowInstrumentType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcFlowInstrumentType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcFlowInstrument</b> override the properties defined at <i>IfcFlowInstrumentType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_FlowInstrumentPHistory.xml"">Pset_FlowInstrumentPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_FlowInstrumentTypeCommon.xml"">Pset_FlowInstrumentTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcflowinstrumenttypeenum.htm"">PRESSUREGAUGE</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_FlowInstrumentTypePressureGauge.xml"">Pset_FlowInstrumentTypePressureGauge</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcflowinstrumenttypeenum.htm"">THERMOMETER</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_FlowInstrumentTypeThermometer.xml"">Pset_FlowInstrumentTypeThermometer</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcbuildingcontrolsdomain/Qto_FlowInstrumentBaseQuantities.xml"">Qto_FlowInstrumentBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFlowInstrument</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcFlowInstrumentType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcFlowInstrument</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the flow instrument occurrence is defined by <i>IfcFlowInstrumentType</i>, then the port occurrences must reflect those defined at the <i>IfcFlowInstrumentType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcFlowInstrument</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives signal.</li>
</ul>

"
1862;IfcActuator;"<p>An actuator is a mechanical device for moving or controlling a mechanism or system. An actuator takes energy, usually created by air, electricity, or liquid, and converts that into some kind of motion.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcActuator</b> defines the occurrence of any actuator; common information about actuator types is handled by <i>IfcActuatorType</i>. 
The <i>IfcActuatorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcActuatorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcActuatorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcActuator</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcActuatorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcActuatorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcActuator</b> override the properties defined at <i>IfcActuatorType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorPHistory.xml"">Pset_ActuatorPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorTypeCommon.xml"">Pset_ActuatorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorTypeLinearActuation.xml"">Pset_ActuatorTypeLinearActuation</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorTypeRotationalActuation.xml"">Pset_ActuatorTypeRotationalActuation</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcactuatortypeenum.htm"">ELECTRICACTUATOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorTypeElectricActuator.xml"">Pset_ActuatorTypeElectricActuator</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcactuatortypeenum.htm"">HYDRAULICACTUATOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorTypeHydraulicActuator.xml"">Pset_ActuatorTypeHydraulicActuator</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcactuatortypeenum.htm"">PNEUMATICACTUATOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ActuatorTypePneumaticActuator.xml"">Pset_ActuatorTypePneumaticActuator</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcbuildingcontrolsdomain/Qto_ActuatorBaseQuantities.xml"">Qto_ActuatorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcActuator</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcActuatorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcActuator</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontroller.htm"">IfcFlowController</a></b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>): Indicates a connected valve, damper, or switch controlled by the actuator.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcActuator</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the actuator occurrence is defined by <i>IfcActuatorType</i>, then the port occurrences must reflect those defined at the <i>IfcActuatorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcActuator</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives signal.</li>
</ul>

"
1874;IfcController;"<p>A controller is a device that monitors inputs and controls outputs within a building automation system.</p>
              <p>A controller may be physical (having placement within a spatial structure) or logical (a software interface or aggregated within a programmable physical controller).</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcController</b> defines the occurrence of any controller; common information about controller types is handled by <i>IfcControllerType</i>. 
The <i>IfcControllerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcControllerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcControllerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcController</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 177 illustrates controller type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifccontroller-Type.png""></td></tr><tr><td><p class=""figure"">Figure 177 &mdash; Controller type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcControllerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcControllerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcController</b> override the properties defined at <i>IfcControllerType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerPHistory.xml"">Pset_ControllerPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerTypeCommon.xml"">Pset_ControllerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">FLOATING</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerTypeFloating.xml"">Pset_ControllerTypeFloating</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">MULTIPOSITION</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerTypeMultiPosition.xml"">Pset_ControllerTypeMultiPosition</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">PROGRAMMABLE</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerTypeProgrammable.xml"">Pset_ControllerTypeProgrammable</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">PROPORTIONAL</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerTypeProportional.xml"">Pset_ControllerTypeProportional</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">TWOPOSITION</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_ControllerTypeTwoPosition.xml"">Pset_ControllerTypeTwoPosition</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcbuildingcontrolsdomain/Qto_ControllerBaseQuantities.xml"">Qto_ControllerBaseQuantities</a></li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcController</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcController</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li><a href=""./ifccontrollertypeenum.htm"">PROGRAMMABLE</a>
<ul>
<li>May contain IfcController components. Programmable Logic Controllers may be decomposed into logical elements for values and operations.</li>
</ul>
</li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcController</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcControllerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcController</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the controller occurrence is defined by <i>IfcControllerType</i>, then the port occurrences must reflect those defined at the <i>IfcControllerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcController</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccontrollertypeenum.htm"">FLOATING</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the first parameter.</li>
<li><b>Modifier</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the second parameter (if applicable).</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Sets the output value.</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">MULTIPOSITION</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the first parameter.</li>
<li><b>Modifier</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the second parameter (if applicable).</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Sets the output value.</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">PROGRAMMABLE</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Direct communication to the device (e.g. serial port).</li>
<li><b>Data</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Network communication to the device (e.g. TCP/IP network).</li>
<li><b>Input#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Analog or digital inputs.</li>
<li><b>Output#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Analog or digital outputs.</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">PROPORTIONAL</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the first parameter.</li>
<li><b>Modifier</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the second parameter (if applicable).</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Sets the output value.</li>
</ul>
</li>
<li><a href=""./ifccontrollertypeenum.htm"">TWOPOSITION</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the first parameter.</li>
<li><b>Modifier</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives the second parameter (if applicable).</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Sets the output value.</li>
</ul>
</li>
</ul>
<p>Figure 178 illustrates controller port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifccontroller-Port.png""></td></tr><tr><td><p class=""figure"">Figure 178 &mdash; Controller port use</p></td></tr></table>


"
1886;IfcSensor;"<p>A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcSensor</b> defines the occurrence of any sensor; common information about sensor types is handled by <i>IfcSensorType</i>. 
The <i>IfcSensorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcSensorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcSensorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcSensor</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 179 illustrates sensor type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcsensor-Type.png""></td></tr><tr><td><p class=""figure"">Figure 179 &mdash; Sensor type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcSensorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcSensorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcSensor</b> override the properties defined at <i>IfcSensorType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorPHistory.xml"">Pset_SensorPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeCommon.xml"">Pset_SensorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">CONDUCTANCESENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeConductanceSensor.xml"">Pset_SensorTypeConductanceSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">CONTACTSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeContactSensor.xml"">Pset_SensorTypeContactSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">FIRESENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeFireSensor.xml"">Pset_SensorTypeFireSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">FLOWSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeFlowSensor.xml"">Pset_SensorTypeFlowSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">GASSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeGasSensor.xml"">Pset_SensorTypeGasSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">HEATSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeHeatSensor.xml"">Pset_SensorTypeHeatSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">HUMIDITYSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeHumiditySensor.xml"">Pset_SensorTypeHumiditySensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">IONCONCENTRATIONSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeIonConcentrationSensor.xml"">Pset_SensorTypeIonConcentrationSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">LEVEL</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeLevelSensor.xml"">Pset_SensorTypeLevelSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">LIGHTSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeLightSensor.xml"">Pset_SensorTypeLightSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">MOISTURESENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeMoistureSensor.xml"">Pset_SensorTypeMoistureSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">MOVEMENTSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeMovementSensor.xml"">Pset_SensorTypeMovementSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">PHSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypePHSensor.xml"">Pset_SensorTypePHSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">PRESSURESENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypePressureSensor.xml"">Pset_SensorTypePressureSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">RADIATIONSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeRadiationSensor.xml"">Pset_SensorTypeRadiationSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">RADIOACTIVITYSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeRadioactivitySensor.xml"">Pset_SensorTypeRadioactivitySensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">SMOKESENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeSmokeSensor.xml"">Pset_SensorTypeSmokeSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">SOUNDSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeSoundSensor.xml"">Pset_SensorTypeSoundSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">TEMPERATURESENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeTemperatureSensor.xml"">Pset_SensorTypeTemperatureSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsensortypeenum.htm"">WINDSENSOR</a>
<ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_SensorTypeWindSensor.xml"">Pset_SensorTypeWindSensor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcbuildingcontrolsdomain/Qto_SensorBaseQuantities.xml"">Qto_SensorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcSensor</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcSensorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcSensor</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm"">IfcDistributionFlowElement</a></b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>): Sensors may be connected to a flow element for which an aspect of the fluid or flow is measured.</li>
<li><b><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Sensors may be attached to the exterior of an element.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcSensor</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the sensor occurrence is defined by <i>IfcSensorType</i>, then the port occurrences must reflect those defined at the <i>IfcSensorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcSensor</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Transmits signal.</li>
</ul>
<p>Figure 180 illustrates sensor port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcsensor-Port.png""></td></tr><tr><td><p class=""figure"">Figure 180 &mdash; Sensor port use</p></td></tr></table>


"
1913;IfcAlarm;"<p>An alarm is a device that signals the existence of a condition or situation that is outside the boundaries of normal expectation or that activates such a device.</p>
              <p>Alarms include the provision of break glass buttons and manual pull boxes that are used to activate alarms.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcAlarm</b> defines the occurrence of any alarm; common information about alarm types is handled by <i>IfcAlarmType</i>. 
The <i>IfcAlarmType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcAlarmType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcAlarmType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcAlarm</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcAlarmType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcAlarmType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcAlarm</b> override the properties defined at <i>IfcAlarmType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_AlarmPHistory.xml"">Pset_AlarmPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_AlarmTypeCommon.xml"">Pset_AlarmTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcbuildingcontrolsdomain/Qto_AlarmBaseQuantities.xml"">Qto_AlarmBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcAlarm</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcAlarmType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcAlarm</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the alarm occurrence is defined by <i>IfcAlarmType</i>, then the port occurrences must reflect those defined at the <i>IfcAlarmType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcAlarm</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives signal.</li>
</ul>

"
1926;IfcUnitaryControlElement;"<p>A unitary control element combines a number of control components into a single product, such as a thermostat or humidistat.</p>
<p>A unitary control element provides a housing for an aggregation of control or electrical distribution elements that, in combination, perform a singular (unitary) purpose. Each item in the aggregation may have its own geometric representation and location.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcUnitaryControlElement</b> defines the occurrence of any unitary control element; common information about unitary control element types is handled by <i>IfcUnitaryControlElementType</i>. 
The <i>IfcUnitaryControlElementType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcUnitaryControlElementType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcUnitaryControlElementType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcUnitaryControlElement</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 181 illustrates unitary control element type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcunitarycontrolelement-Type.png""></td></tr><tr><td><p class=""figure"">Figure 181 &mdash; Unitary control element type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcUnitaryControlElementType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcUnitaryControlElementType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcUnitaryControlElement</b> override the properties defined at <i>IfcUnitaryControlElementType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_UnitaryControlElementPHistory.xml"">Pset_UnitaryControlElementPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcbuildingcontrolsdomain/Pset_UnitaryControlElementTypeCommon.xml"">Pset_UnitaryControlElementTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcbuildingcontrolsdomain/Qto_UnitaryControlElementBaseQuantities.xml"">Qto_UnitaryControlElementBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcUnitaryControlElement</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcUnitaryControlElementType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcUnitaryControlElement</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm"">IfcDistributionFlowElement</a></b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>): Sensors may be connected to a flow element for which an aspect of the fluid or flow is measured.</li>
<li><b><a href=""../../ifcproductextension/lexical/ifcelement.htm"">IfcElement</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Sensors may be attached to the exterior of an element.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcUnitaryControlElement</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the unitary control element occurrence is defined by <i>IfcUnitaryControlElementType</i>, then the port occurrences must reflect those defined at the <i>IfcUnitaryControlElementType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcUnitaryControlElement</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcunitarycontrolelementtypeenum.htm"">THERMOSTAT</a>
<ul>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Receives power (typically 24V), and closes the circuit for Fan, Heat, and Cool. Port may be aggregated into sub-ports: 'Fan'(SIGNAL,SOURCE), 'Heat'(SIGNAL,SOURCE), and 'Cool'(SIGNAL,SOURCE)</li>
</ul>
</li>
</ul>
<p>Figure 182 illustrates unitary control element port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcunitarycontrolelement-Port.png""></td></tr><tr><td><p class=""figure"">Figure 182 &mdash; Unitary control element port use</p></td></tr></table>


"
1941;IfcSensorType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcSensorType</b> defines commonly shared information for occurrences of sensors.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a sensor specification (i.e. the specific product information, that is common to all occurrences of that product type).  Sensor types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcSensorType</b> are represented by instances of <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensor.htm"">IfcSensor</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeCommon.xml"" target=""SOURCE"">Pset_SensorTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeConductanceSensor.xml"" target=""SOURCE"">Pset_SensorTypeConductanceSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">CONDUCTANCESENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeContactSensor.xml"" target=""SOURCE"">Pset_SensorTypeContactSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">CONTACTSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeFireSensor.xml"" target=""SOURCE"">Pset_SensorTypeFireSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">FIRESENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeFlowSensor.xml"" target=""SOURCE"">Pset_SensorTypeFlowSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">FLOWSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeGasSensor.xml"" target=""SOURCE"">Pset_SensorTypeGasSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">GASSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeHeatSensor.xml"" target=""SOURCE"">Pset_SensorTypeHeatSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">HEATSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeHumiditySensor.xml"" target=""SOURCE"">Pset_SensorTypeHumiditySensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">HUMIDITYSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeIonConcentrationSensor.xml"" target=""SOURCE"">Pset_SensorTypeIonConcentrationSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">IONCONCENTRATIONSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeLevelSensor.xml"" target=""SOURCE"">Pset_SensorTypeLevelSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">LEVELSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeLightSensor.xml"" target=""SOURCE"">Pset_SensorTypeLightSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">LIGHTSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeMoistureSensor.xml"" target=""SOURCE"">Pset_SensorTypeMoistureSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">MOISTURESENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeMovementSensor.xml"" target=""SOURCE"">Pset_SensorTypeMovementSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">MOVEMENTSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypePHSensor.xml"" target=""SOURCE"">Pset_SensorTypePHSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">PHSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypePressureSensor.xml"" target=""SOURCE"">Pset_SensorTypePressureSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">PRESSURESENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeRadiationSensor.xml"" target=""SOURCE"">Pset_SensorTypeRadiationSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">RADIATIONSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeRadioactivitySensor.xml"" target=""SOURCE"">Pset_SensorTypeRadioactivitySensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">RADIOACTIVITYSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeSmokeSensor.xml"" target=""SOURCE"">Pset_SensorTypeSmokeSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">SMOKESENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeSoundSensor.xml"" target=""SOURCE"">Pset_SensorTypeSoundSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">SOUNDSENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeTemperatureSensor.xml"" target=""SOURCE"">Pset_SensorTypeTemperatureSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">TEMPERATURESENSOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_SensorTypeWindSensor.xml"" target=""SOURCE"">Pset_SensorTypeWindSensor</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensortypeenum.htm"">WINDSENSOR</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSensorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcSensorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcsensor.htm"">IfcSensor</a> for standard port definitions.</p> 
 
</EPM-HTML>"
1944;IfcControllerType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcControllerType</b> defines commonly shared information for occurrences of controllers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a controller specification (i.e. the specific product information, that is common to all occurrences of that product type).  Controller types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcControllerType</b> are represented by instances of <a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontroller.htm"">IfcController</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ControllerTypeCommon.xml"" target=""SOURCE"">Pset_ControllerTypeCommon</a></li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ControllerTypeFloating.xml"" target=""SOURCE"">Pset_ControllerTypeFloating</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontrollertypeenum.htm"">FLOATING</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ControllerTypeMultiPosition.xml"" target=""SOURCE"">Pset_ControllerTypeMultiPosition</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontrollertypeenum.htm"">MULTIPOSITION</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ControllerTypeProgrammable.xml"" target=""SOURCE"">Pset_ControllerTypeProgrammable</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontrollertypeenum.htm"">PROGRAMMABLE</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ControllerTypeProportional.xml"" target=""SOURCE"">Pset_ControllerTypeProportional</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontrollertypeenum.htm"">PROPORTIONAL</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ControllerTypeTwoPosition.xml"" target=""SOURCE"">Pset_ControllerTypeTwoPosition</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontrollertypeenum.htm"">TWOPOSITION</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcControllerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcControllerType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcControllerType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontrollertypeenum.htm"">PROGRAMMABLE</a>: May contain <a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontroller.htm"">IfcController</a> components.  Programmable Logic Controllers may be decomposed into logical elements for values and operations.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcControllerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcbuildingcontrolsdomain/lexical/ifccontroller.htm"">IfcController</a> for standard port definitions.</p> 
 
</EPM-HTML>"
1947;IfcActuatorType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcActuatorType</b> defines commonly shared information for occurrences of actuators.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a actuator specification (i.e. the specific product information, that is common to all occurrences of that product type).  Actuator types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcActuatorType</b> are represented by instances of <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuator.htm"">IfcActuator</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ActuatorTypeCommon.xml"" target=""SOURCE"">Pset_ActuatorTypeCommon</a></li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ActuatorTypeElectricActuator.xml"" target=""SOURCE"">Pset_ActuatorTypeElectricActuator</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuatortypeenum.htm"">ELECTRICACTUATOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ActuatorTypeHydraulicActuator.xml"" target=""SOURCE"">Pset_ActuatorTypeHydraulicActuator</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuatortypeenum.htm"">HYDRAULICACTUATOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ActuatorTypeLinearActuation.xml"" target=""SOURCE"">Pset_ActuatorTypeLinearActuation</a></li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ActuatorTypePneumaticActuator.xml"" target=""SOURCE"">Pset_ActuatorTypePneumaticActuator</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuatortypeenum.htm"">PNEUMATICACTUATOR</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_ActuatorTypeRotationalActuation.xml"" target=""SOURCE"">Pset_ActuatorTypeRotationalActuation</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcActuatorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcActuatorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuator.htm"">IfcActuator</a> for standard port definitions.</p> 
 
</EPM-HTML>"
1950;IfcFlowInstrumentType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcFlowInstrumentType</b> defines commonly shared information for occurrences of flow instruments.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a flow instrument specification (i.e. the specific product information, that is common to all occurrences of that product type).  Flow Instrument types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcFlowInstrumentType</b> are represented by instances of <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcflowinstrument.htm"">IfcFlowInstrument</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_FlowInstrumentTypeCommon.xml"" target=""SOURCE"">Pset_FlowInstrumentTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_FlowInstrumentTypePressureGauge.xml"" target=""SOURCE"">Pset_FlowInstrumentTypePressureGauge</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcflowinstrumenttypeenum.htm"">PRESSUREGAUGE</a>)</li> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_FlowInstrumentTypeThermometer.xml"" target=""SOURCE"">Pset_FlowInstrumentTypeThermometer</a> (<a href=""../../ifcbuildingcontrolsdomain/lexical/ifcflowinstrumenttypeenum.htm"">THERMOMETER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFlowInstrumentType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcFlowInstrumentType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcflowinstrument.htm"">IfcFlowInstrument</a> for standard port definitions.</p> 
 
</EPM-HTML>"
1953;IfcAlarmType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcAlarmType</b> defines commonly shared information for occurrences of alarms.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a alarm specification (i.e. the specific product information, that is common to all occurrences of that product type).  Alarm types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcAlarmType</b> are represented by instances of <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcalarm.htm"">IfcAlarm</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_AlarmTypeCommon.xml"" target=""SOURCE"">Pset_AlarmTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcAlarmType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcAlarmType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcalarm.htm"">IfcAlarm</a> for standard port definitions.</p> 
 
</EPM-HTML>"
1956;IfcUnitaryControlElementType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcUnitaryControlElementType</b> defines commonly shared information for occurrences of unitary control elements.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a unitary control element specification (i.e. the specific product information, that is common to all occurrences of that product type).  Unitary Control Element types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcUnitaryControlElementType</b> are represented by instances of <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcunitarycontrolelement.htm"">IfcUnitaryControlElement</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcBuildingControlsDomain/Pset_UnitaryControlElementTypeCommon.xml"" target=""SOURCE"">Pset_UnitaryControlElementTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcUnitaryControlElementType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcUnitaryControlElementType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcbuildingcontrolsdomain/lexical/ifcunitarycontrolelement.htm"">IfcUnitaryControlElement</a> for standard port definitions.</p> 
 
</EPM-HTML>"
1960;IfcStructuralItem;"<EPM-HTML>

<p><u>Definition from IAI:</u> The abstract entity <i>IfcStructuralItem</i> is the generalization of structural members and structural connections, i.e. analysis idealizations of elements in the building model.  It defines the relation between structural members and connections with structural activities (actions and reactions).</p>

<p>Relationships between elements in the building model and structural items as their idealizations can be expressed by instances of <i>IfcRelAssignsToProduct</i>.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change:  Use definitions and informal proposition added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>The following coordinate systems are distinguished:</p>

<ul>
  <li>The so-called global coordinate system is the coordinate system shared by all items and activities which are grouped in a common <i>IfcStructuralAnalysisModel</i>.  This coordinate system is established by <i>SELF\IfcProduct.ObjectPlacement</i>.  (This coordinate system is not necessarily the same as the <i>IfcProject</i>'s world coordinate system.)</li>
  <li>The so-called local coordinate system is a coordinate system local to a structural item (connection or member).  This coordinate system is established by a <i>Representation</i> (attribute inherited from <i>IfcProduct</i>) in conjunction with further use definitions and attributes of subtypes of <i>IfcStructuralItem</i>.</li>
</ul>

<p>Representation items in topology representations are always given within the <i>ObjectPlacement</i>, i.e. in so-called global coordinates (global with respect to the <i>IfcStructuralAnalysisModel</i> to which this item belongs).</i>

<p>The usage of local coordinate systems is further defined in subtypes.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Instances of <i>IfcStructuralItem</i> shall have a topology representation.  It includes a placement and a product representation. The <i>IfcProductRepresentation</i> shall be given by an item in a <i>Representation</i> of type <i>IfcTopologyRepresentation</i>.</p>

<p><b>Local Placement</b></p>

<p>The local placement for <i>IfcStructuralActivity</i> is defined in its supertype <I>IfcProduct</I>.  It is defined by the <i>IfcLocalPlacement</i>, which establishes a global coordinate system which shall be common to all items and activities in an <i>IfcStructuralAnalysisModel</i>.</p>

<p><b>Topology Representation</b></p>

<p>Instances of <i>IfcStructuralItem</i> shall have a topology representation given by an instance of a subtype of <i>IfcTopologicalRepresentationItem</i>, which should be the single item of <i>IfcTopologyRepresentation.Items</i>.  Depending on the dimensionality of the structural item, one of the following types of toplogical representation items shall be used:</p>

<ul>
  <li>Point connections shall be represented by an <i>IfcVertexPoint</i> with an underlying <i>IfcCartesianPoint</i>.
      The Cartesian point is the reference point of the connection in the so-called global coordinate system.
      The following labels are used in the <i>IfcTopologyRepresentation</i>:
      <ul>
        <li><i>RepresentationIdentifier</i>: 'Reference'</li>
        <li><i>RepresentationType</i>: 'Vertex'</li>
      </ul>
      <br>
      </li>

  <li>Curve members and curve connections shall either be represented by an <i>IfcOrientedEdge</i>,
      <i>IfcEdgeCurve</i>, or <i>IfcEdge</i>.  The curve to which the <i>IfcEdgeCurve</i> (or an
      <i>IfcOrientedEdge</i>'s underlying <i>IfcEdgeCurve</i>) refers to is the reference curve of the structural
      item in the global coordinate system.  Start and end vertex of the edge shall be <i>IfcVertexPoint</i>s
      with underlying <i>IfcCartesianPoint</i>s.
      The following labels are used in the <i>IfcTopologyRepresentation</i>:
      <ul>
        <li><i>RepresentationIdentifier</i>: 'Reference'</li>
        <li><i>RepresentationType</i>: 'Edge'</li>
      </ul>
      <blockquote><font size=""-1"">NOTE&nbsp; While an <i>IfcEdge</i> (or <i>IfcOrientedEdge</i> with underlying
      <i>IfcEdge</i>) does not provide an explicit underlying curve geometry, it may be used to imply an
      underlying straight line as reference curve with the origin of the curve parameter at the start vertex
      point.</font></blockquote>
      </li>

  <li>Surface members and surface connections shall be represented by an <i>IfcFaceSurface</i>.
      The underlying surface defeines the reference surface of the structural surface item in the global
      coordiante system.  All edges in the bounds of the face shall conform to the rules for edge
      representations of structural curve item.
      The following labels are used in the <i>IfcTopologyRepresentation</i>:
      <ul>
        <li><i>RepresentationIdentifier</i>: 'Reference'</li>
        <li><i>RepresentationType</i>: 'Face'</li>
      </ul>
      </li>
</ul>

<p>The reference point, reference curve, or reference surface partially or completely defines the local coordinate system of the represented structural item according to the following rules.  In all cases, The local x,y,z directions form a right-handed Cartesian coordinate system.</p>

<p><i>Structural point items</i></p>

<ul>
  <li>The reference point in the representation is the origin of the local coordinate system of the structural item.</li>
  <li>The axes of the local coordiante system are either parallel with and directed like the so-called global coordinate axes, or are oriented according to definitions at the respective subtype of <i>IfcStructuralItem</i>.</li>
</ul>

<p><i>Structural curve items</i></p>

<ul>
  <li>The u parameter origin of the reference curve in the representation is the origin of the local coordinate system of the structural item.</li>
  <li>The local x axis is parallel with the tangent on the curve and directed like the u parameter direction.</li>
  <li>The local y and z axes are oriented according to definitions at the respective subtypes of <i>IfcStructuralItem</i>.</li>
</ul>

<p><i>Structural surface items</i></p>

<ul>
  <li>The u,v parameter origin of the reference surface in the representation is the origin of the local coordinate system of the structural item.</li>
  <li>The local x and y directions follow the tangents on the surface and are in parallel with and directed like u and v respectively.</li>
  <li>The local z direction is in parallel with and directed like the surface normal.</li>
</ul>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>The <i>ObjectPlacement</i>s of all structural items which are grouped into the same instance of <i>IfcStructuralAnalysisModel</i> shall refer to the same instance of <i>IfcObjectPlacement</i>.</li>
</ol>

<blockquote><font size=""-1"">NOTE&nbsp; This rule is necessary to achieve consistent topology representations.  The topology representations of structural items in an analysis model are meant to share vertices and edges und must therefore have the same object placement.</font></blockquote>

<blockquote><font size=""-1"">NOTE&nbsp; A structural item may be grouped into more than one analysis model.  In this case, all these models must use the same instance of <i>IfcObjectPlacement</i>.</font></blockquote>

</EPM-HTML>"
1964;IfcStructuralMember;"<EPM-HTML>

<p><u>Definition from IAI:</u> The abstract entity <i>IfcStructuralMember</i> is the superclass of all structural items which represent the idealized structural behavior of building elements.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change:  Use definitions moved to supertype and subtypes.</font></blockquote>

</EPM-HTML>"
1968;IfcStructuralCurveMember;"<EPM-HTML>

<p><u>Definition from IAI:</u> Instances of <i>IfcStructuralCurveMember</i> describe edge members, i.e. structural analysis idealizations of beams, columns, rods etc..  Curve members may be straight or curved.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attribute <i>Axis</i> and WHERE rule added.  Use definitions changed.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i>.  The local coordinate system is established by the reference curve given by topology representation and by the attribute <i>Axis</i>.  The local x axis is parallel with the tangent on the reference curve.  The local z axis is located in the surface which is created by sweeping <i>Axis</i> along the reference curve and is directed according to <i>Axis</i>.  The local y axis is directed such that x,y,z form a right-handed Cartesian coordinate system.</p>

<p><b><u>Material Use Definition</u></b></p>

<p>The material of direct instances <i>IfcStructuralCurveMember</i> (in contrast to instances of the subtype <i>IfcStructuralCurveMemberVarying</i>) is defined by <i>IfcMaterialProfileSetUsage</i> and attached by the <i>IfcRelAssociatesMaterial.RelatingMaterial</i>.  It is accessible by the inverse <i>HasAssociations</i> relationship.  Composite profile beams can be represented by refering to several <i>IfcMaterialProfile</i>s within the <i>IfcMaterialProfileSet</i> that is referenced from the <i>IfcMaterialProfileSetUsage</i>.  In case of tapered members, the material profile usage subtype <i>IfcMaterialProfileSetUsageDual</i> is used which specifies <i>IfcMaterialProfileSet</i>s separately at the start and the end of the tapered member.</p>

<p>The material (<i>IfcMaterial</i>) in each <i>IfcMaterialProfile</i>(<i>Set</i>) is specified minimally by a name which corresponds with an agreed upon standardized structural material designation.  An external reference to the source which specifies the material designation should be provided.  Alternatively, structural material properties may be provided by means of <i>IfcMechanicalMaterialProperties</i> and <i>IfcExtendedMaterialProperties</i>.</p>

<p>The profile (<i>IfcProfileDef</i>) in each <i>IfcMaterialProfile</i>(<i>Set</i>) is specified minimally by a name which corresponds with an agreed upon standardized structural profile designation.  An external reference to the source which specifies the profile designation should be provided.  Alternatively or additionally, explicit profile geometry should be provided by using respective subtypes of <i>IfcProfileDef</i>.  Alternatively or additionally, structural profile properties may be provided by means of subtypes of <i>IfcProfileProperties</i>.</p>

<p>An <i>IfcProfileDef</i> is a two-dimensional geometric object with a x<sub>p</sub>,y<sub>p</sub> coordinate system.  The profile is inserted into the curve member model thus that the origin of x<sub>p</sub>,y<sub>p</sub> is located at the member's reference curve and that x<sub>p</sub>,y<sub>p</sub> are parallel with and directed like the local y,z.</p>

<blockquote><font size=""-1"">NOTE&nbsp;  Due to convention in structural mechanics, axis names of <i>IfcStructuralCurveMember</i> differ from axis names of building elements like <i>IfcBeamStandardCase</i>:  The extrusion axis of <i>IfcStructuralCurveMember</i> is called x while the extrusion axis of <i>IfcBeamStandardCase</i> is called z.  Hence x,y,z of <i>IfcStructuralCurveMember</i> correspond with z,x,y of <i>IfcBeamStandardCase</i>.</font></blockquote>

<p>If the profile is meant to be inserted centrically in terms of structural section properties, it is necessary that the origin of x<sub>p</sub>,y<sub>p</sub> is identical with the geometric centroid of the profile (commonly also called centre of gravity).  If subtypes of <i>IfcParameterizedProfileDef</i> are used which are only singly symmetric or are asymmetric, an explicit translation by <i>IfcParameterizedProfileDef.Position.Location</i> is required then.</p>

<p>If the profile is inserted at its geometric centroid, <i>IfcMaterialProfileSetUsage.CardinalPoint</i> shall be set to 10.</p>

<p>Otherwise, the profile is inserted eccentrically and a different cardinal point should be set accordingly.</p>

<blockquote><font size=""-1"">NOTE&nbsp;  Another eccentricity model is available independently of eccentric profile specification:  The reference curve of the member may be located eccentrically relative to the reference points of the connected <i>IfcStructuralPointConnection</i>s.  The connection relationship is then established by <i>IfcRelConnectsWithEccentricity</i>.  Whether one or the other or both eccentricity models may be used is subject to information requirements and local agreements.</font></blockquote>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Direct instances of <i>IfcStructuralCurveMember</i> shall have a topology representation which consists of one instance of <i>IfcEdge</i> or a subtype, representing the reference curve of the curve member.  See definitions at <i>IfcStructuralItem</i> for further specifications.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>The reference curve must not be parallel with <i>Axis</i> at any point within the curve member's domain.</li>
</ol>

</EPM-HTML>"
1973;IfcStructuralCurveMemberVarying;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes edge members with varying profile properties.  Each instance of <i>IfcStructuralCurveMemberVarying</i> is composed of two or more instances of <i>IfcStructuralCurveMember</i> with differing profile properties.  These subordinate members relate to the instance of <i>IfcStructuralCurveMemberVarying</i> by <i>IfcRelAggregates</i>.</p>

<blockquote><font size=""-1"">NOTE&nbsp;  A curve member whose variation of profile properties can be sufficiently described by a start profile and an end profile (e.g. tapers) shall be modeled as a single direct instance of the supertype <i>IfcStructuralCurveMember</i>.</font></blockquote>

<blockquote><font size=""-1"">NOTE&nbsp;  It is recommended that structural activities (actions or reactions) are not connected with aggregated <i>IfcStructuralCurveMemberVarying</i> but only with the <i>IfcStructuralCurveMember</i>s in the aggregation.  That way, difficulties in interpretation of local coordinates are avoided.</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
Use definition changed in IFC 2x4.</font></blockquote>


<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i> and <i>IfcStructuralCurveMember</i>.  The local coordinates of the aggregate are derived from those of its parts.  Length measures in local x direction of the aggregate depend on continuity and lengths of the parts.  The <i>Axis</i> of the aggregate shal be the same as the <i>Axis</i> of the part at the start of the aggregate.</p>

<p><b><u>Material Use Definition</u></b></p>

<p>Only the individual parts (direct instances of <i>IfcStructuralCurveMember</i>) carry material and profile information.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Instances of <i>IfcStructuralCurveMemberVarying</i> may have a topology representation which contains a single <i>IfcEdgeLoop</i>, based upon the edges of the parts.</p>

</EPM-HTML>"
1982;IfcStructuralSurfaceMember;"<EPM-HTML>

<p><u>Definition from IAI:</u> Instances of <i>IfcStructuralSurfaceMember</i> describe face members, i.e. structural analysis idealizations of slabs, walls, shells, etc..  Surface members may be planar or curved.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change:  Use definitions changed, WHERE rule added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i>.  The local coordinate system is established by the reference surface given by topology representation.</p>

<p><b><u>Material Use Definition</u></b></p>

<p>The material of direct instances <i>IfcStructuralSurfaceMember</i> (in contrast to instances of the subtype <i>IfcStructuralSurfaceMemberVarying</i>) is defined by <i>IfcMaterial</i> and attached by the <i>IfcRelAssociatesMaterial.RelatingMaterial</i>.  It is accessible by the inverse <i>HasAssociations</i> relationship.</p>

<p>The material is specified minimally by a name which corresponds with an agreed upon standardized structural material designation.  An external reference to the source which specifies the material designation should be provided.  Alternatively, structural material properties may be provided by means of <i>IfcMechanicalMaterialProperties</i> and <i>IfcExtendedMaterialProperties</i>.</p>

<p>Direct instances of <i>IfcStructuralSurfaceMember</i> are assumed to be located centrically relative to their reference surface.  Their depth is provided in the attribute <i>Thickness</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Direct instances of <i>IfcStructuralSurfaceMember</i> shall have a topology representation which consists of one <i>IfcFaceSurface</i>, representing the reference surface of the surface member.  See definitions at <i>IfcStructuralItem</i> for further specifications.</p>

</EPM-HTML>"
1987;IfcStructuralSurfaceMemberVarying;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes surface members with varying section properties.  The properties are provided by means of a property set and <i>IfcRelDefinesByProperties</i> or by means of aggregation:  An instance of <i>IfcStructuralSurfaceMemberVarying</i> may be composed of two or more instances of <i>IfcStructuralSurfaceMember</i> with differing section properties.  These subordinate members relate to the instance of <i>IfcStructuralSurfaceMemberVarying</i> by <i>IfcRelAggregates</i>.</p>

<blockquote><font size=""-1"">NOTE&nbsp;  It is recommended that structural activities (actions or reactions) are not connected with aggregated <i>IfcStructuralSurfaceMemberVarying</i> but only with the <i>IfcStructuralSurfaceMember</i>s in the aggregation.  That way, difficulties in interpretation of local coordinates are avoided.</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
Use definition changed and attributes deleted in IFC 2x4.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i> and <i>IfcStructuralSurfaceMember</i>.  The local coordinates of an aggregate are generally undefined since continuity of local coordinates of the parts is not ensured.</p>

<p><b><u>Material Use Definition</u></b></p>

<p>In case of aggregation, only the individual parts (direct instances of <i>IfcStructuralSurfaceMember</i>) carry material and thickness information.  Otherwise, definitions at <i>IfcStructuralSurfaceMember</i> apply.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>In case of aggregation, instances of <i>IfcStructuralSurfaceMemberVarying</i> may have a topology representation which contains a single <i>IfcConnectedFaceSet</i>, based upon the faces of the parts.  Otherwise, definitions at <i>IfcStructuralSurfaceMember</i> apply.</p>

</EPM-HTML>"
1994;IfcRelConnectsStructuralMember;"<EPM-HTML>

<p>The entity <i>IfcRelConnectsStructuralMember</i> defines all needed properties describing the connection between structural members and structural connection objects (nodes or supports).</p>

<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x2.</blockquote>

<p><b>Use Definition</b></p>

<p><i>Point Connection</i><br>
Instances of the entity <i>IfcRelConnectsStructuralMember</i> shall be used to describe a connection between an instance of <i>IfcStructuralPointConnection</i> and either an instance of <i>IfcStructuralCurveMember</i> or <i>IfcStructuralSurfaceMember</i>.  The <i>RelatedStructuralConnection</i> for point connections has to be of type <i>IfcStructuralPointConnection</i>.</p>

<p><i>Curve Connection</i><br>
Instances of the entity <i>IfcRelConnectsStructuralMember</i> shall be used to describe a connection between an instance of <i>IfcStructuralCurveConnection</i> and an instance of either <i>IfcStructuralCurveMember</i> or <i>IfcStructuralSurfaceMember</i>.  The <i>RelatedStructuralConnection</i> for curve connections has to be of type <i>IfcStructuralCurveConnection</i>.</p>

<p><i>Surface Connection</i><br>
Instances of the entity <i>IfcRelConnectsStructuralMember</i> shall be used to describe a connection between an instance of <i>IfcStructuralSurfaceConnection</i> and an instance of <i>IfcStructuralSurfaceMember</i>.  The <i>RelatedStructuralConnection</i> for curve connections has to be of type <i>IfcStructuralSurfaceConnection</i>.</p>

<p><i>Coordinate System for Applied Conditions</i><br>
All values defined by <i>AppliedCondition</i> or <i>AdditionalConditions</i> are given within the coordinate system provided by <i>ConditionCoordinateSystem</i>, which is defined relative to the local coordinate system of the structural member.  If the <i>ConditionCoordinateSystem</i> is not defined, the local coordinate system of the structural member is used instead.</p>

<p><i>Supported Length</i><br>
Optionally a supported length can be given, which specifies the length (or width) of the physical connection along a curve connection.</p>

<p>Figure 235 illustrates the appropriate definition of support lengths.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""0"">
  <tr>
    <td>
      <p><img src=""figures/IfcRelConnectsStructuralMember-Fig1.gif"" alt=""supported length"" style=""border: 0px solid ; width: 600px; height: 368px;"" align=""left""></p>
    </td>
  </tr>
  <tr>
    <td>
      <p class=""figure"">Figure 235 &mdash; Structural member support lengths</p>
    </td>
  </tr>
</table>

</EPM-HTML>"
2002;IfcRelConnectsStructuralActivity;"<EPM-HTML>

<p><u>Definition from IAI:</u> The <i>IfcRelConnectsStructuralActivity</i> relationship connects a structural activity (either an action or reaction) to a structural member, structural connection, or element.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2008;IfcStructuralAnalysisModel;"<EPM-HTML>

<p><u>Definition from IAI:</u> The <i>IfcStructuralAnalysisModel</i> is used to assemble all information needed to represent a structural analysis model.  It encompasses certain general properties (such as analysis type), references to all contained structural members, structural supports or connections, as well as loads and the respective load results.</p>

<p>Important functionalities for the description of an analysis model are derived from existing IFC entities:</p>

<ul>
  <li>From <i>IfcSystem</i> it inherits the ability to couple the analysis model via <i>IfcRelServicesBuildings</i> to one or more <i>IfcBuilding</i>s as necessary.</li>
  <li>From <i>IfcGroup</i> it inherits the inverse attribute <i>IsGroupedBy</i>, pointing to the relationship class <i>IfcRelAssignsToGroup</i>.  This allows to group structural members (instances of <i>IfcStructuralMember</i>), and supports (instances of <i>IfcStructuralConnection</i>) which belong to a specific analysis model.
      <blockquote><font size=""-1"">NOTE:  Loads (as instances of <i>IfcStructuralAction</i>) are not included through <i>IsGroupedBy</i>.  Loads are assigned through the <i>LoadedBy</i> attribute relationship, using load groups as a grouping mechanism.  Only top-level load groups should be referenced via <i>LoadedBy</i>, i.e. load combinations if any load combinations exist, or load cases if no load combinations exist in this analysis model.</font></blockquote>
      <blockquote><font size=""-1"">NOTE:  Results (as instances of <i>IfcStructuralReaction</i>) are not included through <i>IsGroupedBy</i>.  Results are assigned through the <i>HasResults</i> attribute relationship, using result groups as a grouping mechanism.</font></blockquote>
  </li>
  <li>From <i>IfcObject</i> it inherits the inverse attribute <i>IsDecomposedBy</i> pointing to the relationship class <i>IfcRelNests</i>. It provides the hierarchy between the separate (partial) analysis models.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attribute <i>SharedPlacement</i> and informal propositions added, allowing for easy retrieval of the common object placement and for specification of the analysis model's coordiante system before any structural item is instantiated.  WHERE rule added.</font></blockquote>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>If one or more structural item (instance of a subtype of <i>IfcStructuralItem</i>) is grouped into an <i>IfcStructuralAnalysisModel</i>, the attribute <i>SharedPlacement</i> shall be provided with a value.</li>
  <li>The <i>ObjectPlacement</i>s of all structural items which are grouped into the same instance of <i>IfcStructuralAnalysisModel</i> shall refer to the same instance of <i>IfcObjectPlacement</i> as <i>IfcStructuralAnalysisModel.SharedPlacement</i>.</li>
</ol>

<blockquote><font size=""-1"">NOTE&nbsp; This rule is necessary to achieve consistent topology representations.  The topology representations of structural items in an analysis model are meant to share vertices and edges und must therefore have the same object placement.</font></blockquote>

<blockquote><font size=""-1"">NOTE&nbsp; A structural item may be grouped into more than one analysis model.  In this case, all these models must use the same instance of <i>IfcObjectPlacement</i>.</font></blockquote>


</EPM-HTML>"
2021;IfcStructuralLoadGroup;"<EPM-HTML>

<p><u>Definition from IAI:</u> The entity <i>IfcStructuralLoadGroup</i> is used to structure the
physical impacts.  By using the grouping features inherited from <i>IfcGroup</i>, instances of
<i>IfcStructuralAction</i> (or its subclasses) and of <i>IfcStructuralLoadGroup</i> can be used to
define load groups, load cases and load combinations.  (See also <i>IfcLoadGroupTypeEnum</i>.)</p>

<blockquote><font size=""-1"">NOTE: Important functionality for the description of a load-bearing system
is derived from the existing IFC entity <i>IfcGroup</i>.  This class provides, via the relationship
class <i>IfcRelAssignsToGroup</i>, the needed grouping mechanism.  In this way, instances of
<i>IfcStructuralAction</i> belonging to a specific load group can be unambiguously determined.
</font></blockquote>

<blockquote><font size=""-1"">NOTE: The relationship class <i>IfcRelAssignsToGroupByFactor</i> is
used to group load cases into load combinations.  The factor provided in this assignment relationship
is to applied together with the optional <i>IfcStructuralLoadGroup.Coefficient</i>.  Unlike this
coefficient which always affects the load group, the <i>IfcRelAssignsToGroupByFactor.Factor</i> is
specific for a load case&mdash;load combination pair.  As many instances of
<i>IfcRelAssignsToGroupByFactor</i> are used within one load combination as there are different
<i>Factor</i>s to be applied to load cases in the load combination.
</font></blockquote>

<blockquote><font size=""-1"">On the other hand, a load case may appear in more than one load combination
and can have a different <i>Factor</i> in each assignment by <i>IfcRelAssignsToGroupByFactor</i>.
</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change: Subtype <i>IfcStructuralLoadCase</i> added.  Informal propositions and WHERE rule added.
Predefined type LOAD_COMBINATION_GROUP made obsolete and removed.</font></blockquote>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>Load groups of type LOAD_GROUP shall only contain instances of <i>IfcStructuralAction</i>.</li>
  <li>Load groups of type LOAD_CASE shall always be instantiated from the subtype <i>IfcStructuralLoadCase</i>,
      not directly from the generic type <i>IfcStructuralLoadGroup</i> itself.</li>
  <li>Instances of <i>IfcStructuralLoadCase</i> shall only contain instances of <i>IfcStructuralAction</i>
      or/ and instances of <i>IfcStructuralLoadGroup</i> of type LOAD_GROUP.</li>
  <li>Load groups of type LOAD_COMBINATION shall only contain instances of <i>IfcStructuralLoadCase</i>.</li>
</ol>

</EPM-HTML>"
2031;IfcStructuralResultGroup;"<EPM-HTML>

<p><u>Definition from IAI:</u> Instances of the entity <i>IfcStructuralResultGroup</i> are used to group results of structural analysis calculations and to capture the connection to the underlying basic load group.  The basic functionality for grouping inherited from <i>IfcGroup</i> is used to collect instances from <i>IfcStructuralReaction</I> or its respective subclasses.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change: WHERE rule added.</font></blockquote>

</EPM-HTML>"
2044;IfcStructuralLoadCase;"<EPM-HTML>

<p><u>Definition from IAI:</u> A load case is a load group, commonly used to group loads from the same action source.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

</EPM-HTML>"
2087;IfcStructuralActivity;"<EPM-HTML>

<p><u>Definition from IAI:</u> The abstract entity <i>IfcStructuralActivity</i> combines the definition of actions (such as forces, displacements, etc.) and reactions (support reactions, internal forces, deflections, etc.) which are specified by using the basic load definitions from the <i>IfcStructuralLoadResource</i>.</p>

<p>The differentiation between actions and reactions is realized by instantiating objects either from subclasses of <i>IfcStructuralAction</i> or <i>IfcStructuralReaction</i> respectively.  They inherit commonly needed attributes from the abstract superclass <i>IfcStructuralActivity</i>, notably the relationship which connects actions or reactions with connections, analysis members, or elements (subtypes of <i>IfcStructuralItem</i> or <i>IfcElement</i>).</p>

<blockquote><font size=""-1"">NOTE&nbsp; Instances of <i>IfcStructuralActivity</i> which are connected with an <i>IfcElement</i> are subject to agreements outside the scope of this specification.</font></blockquote>

<blockquote><font size=""-1"">NOTE&nbsp; The semantics of <i>IfcStructuralActivity</i> are only fully defined
if an activity instance is connected with exactly one structural item.  The inverse attribute
<i>AssignedToStructuralItem</i> can only be empty in incomplete models or in conceptual models
which are not yet ready for analysis.</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">IFC 2x4 change:  Cardinality of attribute
<i>AssignedToStructuralItem</i> relaxed from 1 to 0..1 in order to allow for schema-compliant
incomplete models as well as conceptual models without load&mdash;item relationships.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>The following coordinate systems are distinguished:</p>

<ul>
  <li>The so-called global coordinate system is the coordinate system shared by all items and activities which are grouped in a common <i>IfcStructuralAnalysisModel</i>.  This coordinate system is established by an <i>ObjectPlacement</i>.  (This coordinate system is not necessarily the same as the <i>IfcProject</i>'s world coordinate system.)</li>
  <li>The so-called local coordinate system is a coordinate system local to a structural item (connection or member).  This coordinate system is established by a <i>Representation</i> in conjunction with further use definitions and attributes of subtypes of <i>IfcStructuralItem</i>.</li>
</ul>

<p>Representation items in topology representations are always given within the <i>ObjectPlacement</i>, i.e. in so-called global coordinates (global with respect to the <i>IfcStructuralAnalysisModel</i> to which this activity belongs).</i>

<p>Locations of the load objects in the <i>AppliedLoad</i> attribute (if of type <i>IfcStructuralLoadConfiguration</i>) are always given in local coordinates.</p>

<p>Directions of the load objects in the <i>AppliedLoad</i> attribute refer to global or local coordinates according to the <i>GlobalOrLocal</i> attribute.</p>

<p>The <i>ObjectPlacement</i> and <i>Representation</i> are sometimes not explicitly instantiated; instead they may be implied as described below.  Global and local coordinate systems are then determined in the same way as with explicit placement and representation.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Instances of <i>IfcStructuralActivity</i> which are connected with a structural item of same dimensionality, i.e.</p>
<ul>
  <li>a point action or reaction connected with a point item (<i>IfcStructuralPointConnection</i>),</li>
  <li>a curve action or reaction connected with a curve item (<i>IfcStructuralCurveConnection</i>, <i>IfcStructuralCurveMember</i>), or</li>
  <li>a surface action or reaction connected with a surface item (<i>IfcStructuralSurfaceConnection</i>, <i>IfcStructuralSurfaceMember</i>) and which acts on the entire surface of the item and is not specified by isocontours</li>
</ul>
<p>shall not have an <i>ObjectPlacement</i> nor a <i>Representation</i>.  It is implied that the placement and representation of the <i>IfcStructuralActivity</i> is the same as the ones of the <i>IfcStructuralItem</i>.</p>

<p>Instances of <i>IfcStructuralActivity</i> which are connected with</p>
<ul>
  <li>a curve item (<i>IfcStructuralCurveConnection</i>, <i>IfcStructuralCurveMember</i>) and act on a point of the item</li>, or
  <li>a surface item (<i>IfcStructuralSurfaceConnection</i>, <i>IfcStructuralSurfaceMember</i>) and act on a point or on a curve or on a part of the surface of the item</li>
</ul>
<p>shall have a topology representation as specified below.  It includes a placement and a product representation. The <i>IfcProductRepresentation</i> shall be given by an item in a <i>Representation</i> of type <i>IfcTopologyRepresentation</i>.</p>

<p>Instances of <i>IfcStructuralActivity</i> which are connected with</p>
<ul>
  <li>a surface item (<i>IfcStructuralSurfaceConnection</i>, <i>IfcStructuralSurfaceMember</i>) and are specified by isocontours</li>
</ul>
<p>shall have a shape representation as specified below.  It includes a placement and a product representation. The <i>IfcProductRepresentation</i> shall be given by items in a <i>Representation</i> of type <i>IfcShapeRepresentation</i>.  Shape representation and topology representation may be combined.</p>

<p><b>Local Placement</b></p>

<p>The local placement for <i>IfcStructuralActivity</i> is defined in its supertype <I>IfcProduct</I>.  It is defined by the <i>IfcLocalPlacement</i>, which establishes a global coordinate system which shall be common to all items and activities in an <i>IfcStructuralAnalysisModel</i>.</p>

<p><b>Topology Representation</b></p>

<p>Instances of <i>IfcStructuralActivity</i> which act on parts of a surface item shall have a topology representation given by a face with underlying surface geometry, <i>IfcFaceSurface</i>, which should be the single item of <i>IfcTopologyRepresentation.Items</i>.  The surface establishes a local coordinate system of the activity:</p>
<ul>
  <li>The origin of surface parameters u,v is the origin of the local coordinate system.</li>
  <li>The local x and y directions follow the tangents on the surface and are in parallel with and directed like u and v respectively.</li>
  <li>The local z direction is in parallel with and directed like the surface normal.</li>
</ul>
<blockquote>
  <ul>
    <li><i>RepresentationIdentifier</i>: 'Reference'</li>
    <li><i>RepresentationType</i>: 'Face'</li>
  </ul>
</blockquote>

<p>Instances of <i>IfcStructuralActivity</i> which act on a curve on a surface item shall have a topology representation given by an edge (<i>IfcEdge</i> or subtype), which should be the single item of <i>IfcTopologyRepresentation.Items</i>.  The curve geometry shall be compatible with the surface geometry of the connected item.  In conjunction with this surface, the curve establishes a local coordinate system of the activity:</p>
<ul>
  <li>The origin of the curve parameter u is the origin of the local coordinate system.</li>
  <li>The local x direction follows the tangent on the curve and is directed like u.</li>
  <li>The local z direction is in parallel with and directed like the surface normal of the connected surface item.</li>
  <li>The local x,y,z directions form a right-handed Cartesian coordinate system.</li>
</ul>
<blockquote>
  <ul>
    <li><i>RepresentationIdentifier</i>: 'Reference'</li>
    <li><i>RepresentationType</i>: 'Edge'</li>
  </ul>
</blockquote>
<blockquote><font size=""-1"">NOTE&nbsp; While an <i>IfcEdge</i> (or <i>IfcOrientedEdge</i> with underlying <i>IfcEdge</i>) does not provide an explicit underlying curve geometry, it may be used to imply an underlying straight line as reference curve with the origin of the curve parameter at the start vertex point.</font></blockquote>

<p>Instances of <i>IfcStructuralActivity</i> which act on a single point on a curve or surface item shall have a topology representation given by an <i>IfcVertexPoint</i>, which should be the single item of <i>IfcTopologyRepresentation.Items</i>.  The point geometry shall be compatible with the curve or surface geometry of the connected item.  The local coordinate system of the activity is oriented by the curve or surface geometry of the connected item as described above for activities with edge or face topology.</p>
<blockquote>
  <ul>
    <li><i>RepresentationIdentifier</i>: 'Reference'</li>
    <li><i>RepresentationType</i>: 'Vertex'</li>
  </ul>
</blockquote>

<p><b>Shape Representation</b></p>

<p>Instances of <i>IfcStructuralActivity</i> which act on a surface item and are specified by isocontours (level sets) shall have a shape representation given by a set of curves on a surface, <i>IfcPCurve</i>.  The basis surface shall comply with or preferably be identical with the surface of the structural item to which the activity is connected.  The representation identifier and type of this geometric representation is:</p>
<blockquote>
  <ul>
    <li><i>RepresentationIdentifier</i>: 'Level set'</li>
    <li><i>RepresentationType</i>: 'GeometricCurveSet'</li>
  </ul>
</blockquote>

</EPM-HTML>"
2093;IfcStructuralAction;"<EPM-HTML>

<p><u>Definition from IAI:</u> A structural action is a structural activity that acts upon
a structural item or building element.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY&nbsp; New entity in IFC 2x2.</font></blockquote>
<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attribute <i>DestabilizingLoad</i> made optional.  Attribute <i>CausedBy</i> deleted; use <i>IfcRelAssignsToProduct</i> via <i>ReferencedBy</i> instead.</font></blockquote>

<p>Structural actions are grouped into either an <i>IfcStructuralLoadGroup</i> of predefined
type LOAD_GROUP or, more often, an <i>IfcStructuralLoadCase</i>.  This is accomplished via the
inverse relationship <i>HasAssignments</i> and an <i>IfcRelAssignsToGroup</i> relationship object.
<i>IfcStructuralLoadGroup.LoadGroupFor</i> or <i>IfcStructuralLoadCase.LoadGroupFor</i> respectively
refers to the structural analysis model(s) in which the loads are used.</p>

<p>It is furthermore possible to establish relationships between actions in one analysis model
and reactions in another analysis model which cause the actions.  For example, a support reaction
from one structural system may be taken over as a load onto another supporting structural system.
This is expressed by means of the inverse relationship <i>ReferencedBy</i> of the action and an
<i>IfcRelAssignsToProduct</i> relationship object.  <i>IfcRelAssignsToProduct.Name</i> is set to
'Causes' and <i>IfcRelAssignsToProduct.RelatedObjects</i> refers to an instance of a subtype of
<i>IfcStructuralReaction</i>.</p>

</EPM-HTML>"
2098;IfcStructuralPointAction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines an action which acts on a point.
A point action is typically connected with a point connection.
It may also be connected with a curve member or curve connection,
or surface member or surface connection.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attributes in the supertypes
<i>IfcStructuralActivity</i> and <i>IfcStructuralAction</i> changed.  Use definitions changed,
informal propositions added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Standard Case:<br>
If connected with a point item, instances of <i>IfcStructuralPointAction</i>
shall not have an <i>ObjectPlacement</i> nor a <i>Representation</i>.
It is implied that the placement and representation of the action is the same
as the structural item.</p>

<p>Special Case 1:<br>
If connected with a curve item or surface item, instances of <i>IfcStructuralPointAction</i>
shall have an <i>ObjectPlacement</i> and <i>Representation</i>, containing an <i>IfcVertexPoint</i>.
See <i>IfcStructuralActivity</i> for further definitions.</p>

<blockquote><small>NOTE In order to model concentrated actions on a curve or surface item,
<i>IfcStructuralCurveAction</i> or <i>IfcStructuralSurfaceAction</i> of type DISCRETE is
preferable since they do not require an extra topology representation in this case.
An <i>IfcStructuralPointAction</i> should be used for a concentrated action on a curve or surface
item only when an explicit vertex point representation is actually desired.</small></blockquote>

<p>Special Case 2:<br>
If not connected with a structural item (which may happen in an incomplete or
conceptual model), a point action should have an <i>ObjectPlacement</i> and
<i>Representation</i>, containing an <i>IfcVertexPoint</i>.
See <i>IfcStructuralActivity</i> for further definitions.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li><i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadSingleForce</i> or
      <i>IfcStructuralLoadSingleDisplacement</i>.</li>
</ol>

</EPM-HTML>"
2099;IfcStructuralCurveAction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines an action which is distributed over a curve.
A curve action may be connected with a curve member or curve connection, or
surface member or surface connection.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Former entitiy
<i>IfcStructuralLinearActionVarying</i> from IFC 2x2 has been removed and are replaced
by this entity.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Standard Case:<br>
If connected with a curve item, instances of <i>IfcStructuralCurveAction</i> shall not have an
<i>ObjectPlacement</i> nor a <i>Representation</i>.  It is implied that the placement and
representation of the <i>IfcStructuralActivity</i> is the same as the ones of the member or
connection.</p>

<p>Special Case 1:<br>
If connected with a surface item, instances of <i>IfcStructuralCurveAction</i> shall have an
<i>ObjectPlacement</i> and <i>Representation</i>, containing an <i>IfcEdgeCurve</i>.  See
<i>IfcStructuralActivity</i> for further definitions.</p>

<p>Special Case 2:<br>
If not connected with a structural item (which may happen in an incomplete or conceptual model),
a curve action should have an <i>ObjectPlacement</i> and <i>Representation</i>, containing an
<i>IfcEdgeCurve</i>.  See <i>IfcStructuralActivity</i> for further definitions.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>If the curve action is of the predefined type CONST, SINUS, or PARABOLA,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> must not be of type
      <i>IfcStructuralLoadConfiguration</i>.  In case of SINUS and PARABOLA, the load item
      defines the maximum of the load at the centre of the load distribution.</li>
  <li>If the curve action is of the predefined type LINEAR,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain two items.</li>
  <li>If the curve action is of the predefined type POLYGONAL,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain three or more items.</li>
  <li>If the curve action is of the predefined type DISCRETE,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain two or more items.</li>
  <li>In case of types LINEAR, POLYGONAL, and DISCRETE, the load items shall have
      one-dimensional <i>IfcStructuralLoadConfiguration.Locations</i>, defining the
      location of the load samples in local coordinates of the curve action.
      The load items shall be provided in ascending order according to their locations.
      The first and the last load item define the extent of the load distribution.</i>
  <li>Point actions must be of type DISCRETE, thus contain two or more load points.
      (Single point loads are modeled by <i>IfcStructuralPointAction</i>.)</li>
  <li>All items in <i>SELF\IfcStructuralActivity.AppliedLoad\IfcStructuralLoadConfiguration.Values</i>
      shall be of the same entity type.</li>
</ol>


</EPM-HTML>"
2106;IfcStructuralLinearAction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines an action with constant value which is distributed over a curve.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Intermediate supertype <i>IfcStructuralCurveAction</i> inserted.  Derived attribute <i>PredefinedType</i> added.</font></blockquote>

<blockquote><font size=""-1"">NOTE&nbsp; Like its supertype <i>IfcStructuralCurveAction</i>, this action type may also act on curved edges.</font></blockquote>

</EPM-HTML>"
2121;IfcStructuralSurfaceAction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines an action which is distributed over a surface.
A surface action may be connected with a surface member or surface connection.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Former entity
<i>IfcStructuralPlanarActionVarying</i> from IFC 2x2 has been removed and are replaced
by this entity.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Standard Case:<br>
If connected with a surface item and acting on its entirety, instances of
<i>IfcStructuralCurveAction</i> shall not have an <i>ObjectPlacement</i> nor a
<i>Representation</i>.  It is implied that the placement and representation of the
<i>IfcStructuralActivity</i> is the same as the ones of the member or connection.</p>

<p>Special Case 1:<br>
If connected with a surface item but acting only on a part of it, instances of
<i>IfcStructuralSurfaceAction</i> shall have an <i>ObjectPlacement</i> and
<i>Representation</i>, containing an <i>IfcFaceSurface</i> which topologically
defines the loaded part of the surface.  See <i>IfcStructuralActivity</i> for further
definitions.</p>

<p>Special Case 2:<br>
If not connected with a structural item (which may happen in an incomplete or conceptual model),
a surface action should have an <i>ObjectPlacement</i> and <i>Representation</i>, containing an
<i>IfcFaceSurface</i>.  See <i>IfcStructuralActivity</i> for further definitions.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>If the surface action is of the predefined type CONST,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> must not be of type
      <i>IfcStructuralLoadConfiguration</i>.</li>
  <li>If the surface action is of the predefined type BILINEAR,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain three items
      with two-dimensional <i>IfcStructuralLoadConfiguration.Locations</i>,
      defining the location of the load samples in local coordinates of the
      surface action.</i>
  <li>If the surface action is of the predefined type DISCRETE,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain two or more
      items with two-dimensional locations.</i>
  <li>Point loads must be of type DISCRETE, thus contain two or more load points.
      (Single point loads are modeled by <i>IfcStructuralPointLoad</i>.)</li>
  <li>All items in <i>SELF\IfcStructuralActivity.AppliedLoad\IfcStructuralLoadConfiguration.Values</i>
      shall be of the same entity type.</li>
</ol>

</EPM-HTML>"
2127;IfcStructuralPlanarAction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines an action with constant value which is distributed over a surface.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Intermediate supertype <i>IfcStructuralSurfaceAction</i> inserted.  Derived attribute <i>PredefinedType</i> added.</font></blockquote>

<blockquote><font size=""-1"">NOTE&nbsp; Like its supertype <i>IfcStructuralSurfaceAction</i>, this action type may also act on curved faces.</font></blockquote>

</EPM-HTML>"
2136;IfcStructuralReaction;"<EPM-HTML>

<p><u>Definition from IAI:</u> A structural reaction is a structural activity that results from a
structural action imposed to a structural item or building element.  Examples are support reactions,
internal forces, and deflections.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY&nbsp; New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Inverse attribute <i>Causes</i> deleted; use <i>IfcRelAssignsToProduct</i> via <i>HasAssignments</i> instead.</font></blockquote>

<p>Structural reactions are grouped into <i>IfcStructuralResultGroup</i>s via the inverse
relationship <i>HasAssignments</i> and an <i>IfcRelAssignsToGroup</i> relationship object.
<i>IfcStructuralResultGroup.ResultGroupFor</i> finally refers to the structural analysis model
in which the results occur.</p>

<p>It is furthermore possible to establish relationships between reactions in one analysis model
and actions which they cause in another analysis model.  For example, a support reaction from one
structural system may be taken over as a load onto another supporting structural system.  This is
expressed by means of the inverse relationship <i>HasAssignments</i> of the reaction and an
<i>IfcRelAssignsToProduct</i> relationship object.  <i>IfcRelAssignsToProduct.Name</i> is set to
'Causes' and <i>IfcRelAssignsToProduct.RelatingProduct</i> refers to an instance of a subtype of
<i>IfcStructuralAction</i>.</p>


</EPM-HTML>"
2140;IfcStructuralPointReaction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines a reaction which occurs at a point.
A point reaction is typically connected with a point connection.
It may also be connected with a curve member or curve connection,
or surface member or surface connection.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attributes in the supertypes <i>IfcStructuralActivity</i> and <i>IfcStructuralReaction</i> changed.  Use definitions changed, informal propositions added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Standard Case:<br>
If connected with a point item, instances of <i>IfcStructuralPointReaction</i>
shall not have an <i>ObjectPlacement</i> nor a <i>Representation</i>.
It is implied that the placement and representation of the reaction is the same
as the structural item.</p>

<p>Special Case 1:<br>
If connected with a curve item or surface item, instances of <i>IfcStructuralPointReaction</i>
shall have an <i>ObjectPlacement</i> and <i>Representation</i>, containing an <i>IfcVertexPoint</i>.
See <i>IfcStructuralActivity</i> for further definitions.</p>

<blockquote><small>NOTE In order to model concentrated reactions on a curve or surface item,
<i>IfcStructuralCurveReaction</i> or <i>IfcStructuralSurfaceAction</i> of type DISCRETE is
preferable since they do not require an extra topology representation in this case.
An <i>IfcStructuralPointReaction</i> should be used for a concentrated reaction on a curve or surface
item only when an explicit vertex point representation is actually desired.</small></blockquote>

<p>Special Case 2:<br>
If not connected with a structural item (which may happen in an incomplete or
conceptual model), a point action should have an <i>ObjectPlacement</i> and
<i>Representation</i>, containing an <i>IfcVertexPoint</i>.
See <i>IfcStructuralActivity</i> for further definitions.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li><i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadSingleForce</i> or
      <i>IfcStructuralLoadSingleDisplacement</i>.</li>
</ol>

</EPM-HTML>"
2141;IfcStructuralCurveReaction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines a reaction which occurs distributed over a curve.
A curve reaction may be connected with a curve member or curve connection,
or surface member or surface connection.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Standard Case:<br>
If connected with a curve item, instances of <i>IfcStructuralCurveRection</i> shall not
have an <i>ObjectPlacement</i> nor a <i>Representation</i>.  It is implied that the
placement and representation of the <i>IfcStructuralActivity</i> is the same as the ones
of the member or connection.</p>

<p>Special Case:<br>
If connected with a surface item, instances of <i>IfcStructuralCurveReaction</i> shall
have an <i>ObjectPlacement</i> and <i>Representation</i>, containing an <i>IfcEdgeCurve</i>.
See <i>IfcStructuralActivity</i> for further definitions.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>If the curve reaction is of the predefined type CONST,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> must not be of type
      <i>IfcStructuralLoadConfiguration</i>.</li>
  <li>If the curve reaction is of the predefined type LINEAR,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain two items.</li>
  <li>If the curve reaction is of the predefined type POLYGONAL,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain three or more items.</li>
  <li>If the curve action is of the predefined type DISCRETE,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain two or more items.</li>
  <li>In case of types LINEAR, POLYGONAL, and DISCRETE, the load items shall have
      one-dimensional <i>IfcStructuralLoadConfiguration.Locations</i>, defining the
      location of the result samples in local coordinates of the curve reaction.
      The load items shall be provided in ascending order according to their locations.
      The first and the last load item define the extent of the result distribution.</i>
  <li>If the curve reaction is of the predefined type EQUIDISTANT,
      <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type
      <i>IfcStructuralLoadConfiguration</i> and shall contain two or more items.
      <i>IfcStructuralLoadConfiguration.Locations</i> shall be omitted as it is implicit.
      The load items shall be provided in ascending order.  The first and the last load
      item are located at the beginning and end of the result distribution, respectively.</li>
  <li>All items in <i>SELF\IfcStructuralActivity.AppliedLoad\IfcStructuralLoadConfiguration.Values</i>
      shall be of the same entity type.</li>
</ol>

</EPM-HTML>"
2145;IfcStructuralSurfaceReaction;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines a reaction which occurs distributed over a surface.  A surface reaction may be connected with a surface member or surface connection.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>See definitions at <i>IfcStructuralActivity</i>.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>If the surface reaction is of the predefined type CONST, <i>SELF\IfcStructuralActivity.AppliedLoad</i> must not be of type <i>IfcStructuralLoadConfiguration</i>.</li>
  <li>If the surface reaction is of the predefined type BILINEAR, <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type <i>IfcStructuralLoadConfiguration</i> and shall contain three items with two-dimensional <i>IfcStructuralLoadConfiguration.Locations</i>, defining the location of the result samples in local coordinates of the surface reaction.</i>
  <li>If the surface reaction is of the predefined type DISCRETE, <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type <i>IfcStructuralLoadConfiguration</i> and shall contain two or more items with two-dimensional locations.</i>
  <li>If the surface reaction is of the predefined type ISOCONTOUR, <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be of type <i>IfcStructuralLoadConfiguration</i> and shall contain the same number of items as the set <i>SELF.IfcProduct.Representation.Representations[?].Items</i>.  Each item in the load configuration shall have a two-dimensional location, defining the location of the result samples in local coordinates of the surface reaction.  Each item in <i>SELF\IfcStructuralActivity.AppliedLoad</i> shall be located at exactly one of the isocontours.
  <blockquote><font size=""-1"">NOTE&nbsp;  The set of representation items is unordered, hence result locations are required to correlate result values and isocontours.</font></blockquote>
  <blockquote><font size=""-1"">NOTE&nbsp;  Isocontours are represented as <i>IfcPCurve</i>s which are defined in terms of surface parameters u,v, while result locations are given in local surface item coordinates x,y.  It is strongly recommended that the surface parameterization u,v is scaled 1:1 in order to avoid different scales of u,v versus x,y.  If u,v are scaled 1:1 and the <i>IfcPCurve</i>'s base surface is identical with the surface item's base surface, u,v and local x,y are identical.</font></blockquote>
  </li>
  <li>All items in <i>SELF\IfcStructuralActivity.AppliedLoad\IfcStructuralLoadConfiguration.Values</i> shall be of the same entity type.</li>
</ol>

</EPM-HTML>"
2148;IfcRelConnectsWithEccentricity;"<EPM-HTML>

<p><u>Definition from IAI:</u> The entity <i>IfcRelConnectsWithEccentricity</i> adds the definition of eccentricity to the connection between a structural member and a structural connection (representing either a node or support).</p>

<blockquote><font size=""-1"">NOTE&nbsp;  Another eccentricity model is available independently of eccentric connection specification:  The section profile of a curve member may be inserted eccentrically with respect to the member's reference curve, see definitions at <i>IfcStructuralCurveMember</i>.  Whether one or the other or both eccentricity models may be used is subject to information requirements and local agreements.</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY&nbsp; New entity in IFC 2x3.<br>
Use definitions changed in IFC 2x4 to always require two topology items.</font></blockquote>

<p><b>Use Definition</b></p>

<p><i>Point Connection</i><br>
<i>ConnectionConstraint</i> shall be of type <i>IfcConnectionPointGeometry</i> and shall refer to two instances of <i>IfcVertexPoint</i>.</p>

<p><i>Curve Connection</i><br>
<i>ConnectionConstraint</i> shall be of type <i>IfcConnectionCurveGeometry</i> and shall refer to two instances of <i>IfcEdge</i> or subtypes.</p>

<p><i>Surface Connection</i><br>
<i>ConnectionConstraint</i> shall be of type <i>IfcConnectionSurfaceGeometry</i> and shall refer to two instances of <i>IfcFaceSurface</i>.</p>

</EPM-HTML>"
2150;IfcStructuralConnection;"<EPM-HTML>

<p><u>Definition from IAI:</u> An <i>IfcStructuralConnection</i> represents a structural connection object (node i.e. vertex connection, or edge connection, or surface connection) or supports.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2156;IfcStructuralCurveConnection;"<EPM-HTML>

<p><u>Definition from IAI:</u> Instances of <i>IfcStructuralCurveConnection</i> describe edge 'nodes', i.e. edges where two or more surface members are joined, or edge supports.  Edge curves may be straight or curved.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attribute <i>Axis</i> added, allowing for skewed supports.  Use definitions added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i>.  The local coordinate system is established by the reference curve given by topology representation and by the attribute <i>Axis</i>.  The local x axis is parallel with the tangent on the reference curve.  The local z axis is located in the surface which is created by sweeping <i>Axis</i> along the reference curve and is directed according to <i>Axis</i>.  The local y axis is directed such that x,y,z form a right-handed Cartesian coordinate system.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Instances of <i>IfcStructuralCurveConnection</i> shall have a topology representation which consists of one instance of <i>IfcEdge</i> or a subtype, representing the reference curve of the curve connection.  See definitions at <i>IfcStructuralItem</i> for further specifications.</p>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>The reference curve must not be parallel with <i>Axis</i> at any point within the curve connections's domain.</li>
</ol>

</EPM-HTML>"
2158;IfcStructuralPointConnection;"<EPM-HTML>

<p><u>Definition from IAI:</u> Instances of <i>IfcStructuralPointConnection</i> describe structural nodes or point supports.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change:  Attribute <i>ConditionCoordinateSystem</i> added, allowing for skewed supports.  Use definitions added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i>.  The local coordinate system is established by the reference point given by topology representation and by the attribute <i>ConditionCoordinateSystem</i>.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Instances of <i>IfcStructuralPointConnection</i> shall have a topology representation which consists of one <i>IfcVertexPoint</i>, representing the reference point of the point connection.  See definitions at <i>IfcStructuralItem</i> for further specifications.</p>

</EPM-HTML>"
2160;IfcStructuralSurfaceConnection;"<EPM-HTML>

<p><u>Definition from IAI:</u> Instances of <i>IfcStructuralSurfaceConnection</i> describe face 'nodes', i.e. faces where two or more surface members are joined, or face supports.  Face surfaces may be planar or curved.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change:  Use definitions added.</font></blockquote>

<p><b><u>Coordinate Systems</u></b>:</p>

<p>See definitions at <i>IfcStructuralItem</i>.  The local coordinate system is established by the reference surface given by topology representation.</p>

<p><b><u>Topology Use Definitions</u></b>:</p>

<p>Instances of <i>IfcStructuralSurfaceConnection</i> shall have a topology representation which consists of one <i>IfcFaceSurface</i>, representing the reference surface of the surface connection.  See definitions at <i>IfcStructuralItem</i> for further specifications.</p>

</EPM-HTML>"
2166;IfcGeometricRepresentationContext;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A geometric
representation context is a representation context in which the
geometric representation items are geometrically founded. A
geometric representation context is a distinct coordinate space,
spatially unrelated to other coordinate spaces.</p>

<p><i>IfcGeometricRepresentationContext</i> defines the context that
applies to several shape representations of products within a
project. It defines the type of the context in which the shape
representation is defined, and the numeric precision applicable
to the geometric representation items defined in this context. In
addition it can be used to offset the project coordinate system
from a global point of origin, using the
<i>WorldCoordinateSystem</i> attribute.</p>

<p>As shown in Figure 329, the <i>TrueNorth</i> attribute should be provided if the y axis of the <i>WorldCoordinateSystem</i> does not point to the global northing. Direction of the true north, or geographic northing direction, relative to the underlying project coordinate
system as established by the attribute <i>WorldCoordinateSystem</i>. It is given by a 2 dimensional direction within the xy-plane of the project coordinate system. If not resent, it defaults to [0.,1.] - i.e. the positive Y axis of the project coordinate system equals the geographic northing direction. The direction is provided within project coordinate system and identifies the true north direction (see
figure).</p>

<table summary=""true north"">
<tr><td width=""505"" valign=""top""><img src=""figures/IfcGeometricRepresentationContext_TrueNorth.png"" alt=""TrueNorth"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 329 &mdash; Geometric representation context true north</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp;˙The inherited attribute
<i>ContextType</i> shall have one of the following recognized
values: <strike>'Sketch', 'Outline', 'Design', 'Detail',</strike>
<font color=""#FF0000"">'Model', 'Plan'</font>,
'NotDefined'.
</blockquote>
<p>The use of one instance of
<i>IfcGeometricRepresentationContext</i> to represent the model
(3D) view is mandatory, the use of a second instance of
<i>IfcGeometricRepresentationContext</i> to represent the plan
(2D) view is optional (but needs to be given, if there are scale
dependent plan views), the additional scale or view dependent
contexts need to be handled by using the subtype
<i>IfcGeometricRepresentationSubContext</i> pointing to the model
view (or the plan view) as the <i>ParentContext</i>.</p>

<p>Figure 330 illustrates use of representation contexts defined at <i>IfcProject</i> for 3D model and 2D plan context, including sub
context definitions for different target scales.</p>

<table summary=""figure"" border=""0"">
<tr><td valign=""top""><img src=""figures/IfcGeometricRepresentationContext.png"" alt=""representation context"" border></td></tr>
<tr><td><p class=""figure"">Figure 330 &mdash; Geometric representation context use</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; The definition of this class relates to the ISO 10303 entity geometric_representation_context. Please refer to ISO/IS 10303-42:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp;˙New Entity in IFC Release 2.0
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp;˙Applicable values for <i>ContextType</i> are only 'Model',˙ 'Plan', and˙'NotDefined'. All other sub contexts are now handled by the new subtype in IFC2x Edition 2 <i>IfcGeometricRepresentationSubContext</i>. Upward compatibility for file based exchange is guaranteed.
</blockquote>

</EPM-HTML>"
2174;IfcRepresentationContext;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A representation context is a context in which a set of representation items are related.</p>

<p>The <i>IfcRepresentationContext</i> defines the context to which the <i>IfcRepresentation</i> of a product is related.</p>

<blockquote class=""note"">
NOTE&nbsp; The definition of this class relates to the ISO 10303 entity representation_context. Please refer to ISO/IS 10303-43:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Entity made abstract, had been deprecated from instantiation since
IFC2x2.
</blockquote>

</EPM-HTML>"
2179;IfcRepresentation;"<EPM-HTML> 
    <p>
      <u>Definition from ISO/CD 10303-43:1992</u>: A
      representation is one or more representation items that are
      related in a specified representation context as the
      representation of some concept.
    </p>
    <p>
      <i>IfcRepresentation</i>
      defines the general concept of representing product
      properties.
    </p>
    <p class=""use-head"">Representation Use Definition</p>
    <p>
      Each representation, either <i>IfcShapeRepresentation</i>, or
      <i>IfcTopologyRepresentation</i> shall have a well defined:
    </p>
    <ul>
      <li>
        <i>ContextOfItems</i>: Reference to an
        <i>IfcGeometricRepresentationContext</i> as agreed for 
				this representation.
      </li>
      <li>
        <i>RepresentationIdentifier</i>: Name of the
        representation, for example, 'Body' for 3D shape, 'FootPrint' for
        2D ground view, 'Axis' for reference axis.
      </li>
      <li>
        <i>RepresentationType</i>: Name for the geometric, or
        topological representation type, for example, 'SweptSolid' for 3D
        swept solids, 'Brep' for boundary representation.
      </li>
    </ul>
    <p>
      Values and guidelines for these three items are provided in
      the geometry use definition section at each subtype of
      <i>IfcElement</i>, or in view definitions / implementer
      agreements.
    </p>
    <blockquote class=""note"">
      NOTE&nbsp;˙The definition of this
      entity relates to the ISO 10303 entity representation. Please
      refer to ISO/IS 10303-43:1994 for the final definition of
      the formal standard.
    </blockquote>
    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC Release 2.0
    </blockquote>
    <blockquote class=""change-ifc2x3"">
      IFC2x3 CHANGE&nbsp; The
      inverse attributes <i>LayerAssignments</i>
      and<i>RepresentationMap</i> have been added with upward
      compatibility.
    </blockquote>
    <blockquote class=""change-ifc2x4"">
      IFC2x4 CHANGE&nbsp; Entity
      <i>IfcRepresentation</i> has been changed into an ABSTRACT
      supertype.
    </blockquote>

</EPM-HTML>"
2189;IfcStyleModel;"<EPM-HTML>

<p><i>IfcStyleModel</i> represents the concept of a particular presentation style defined for a material (or other characteristic) of a product or a product component within a representation context. This representation context may (but has not to be) a geometric representation context.</p>

<p><i>IfcStyleModel</i> can be a style representation (presentation style) of a material (via <i>IfcMaterialDefinitionRepresentation</i>), potentially differentiated for different representation contexts (for example, different material hatching depending on the scale of the target representation context).</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

</EPM-HTML>"
2191;IfcStyledRepresentation;"<EPM-HTML>

<p>The <i>IfcStyledRepresentation</i> represents the concept of a styled presentation being a representation of a product or a product component, like material. within a representation context. This representation context does not need to be (but may be) a geometric representation context.</p>

<blockquote class=""note"">
NOTE&nbsp; Current usage of <i>IfcStyledRepresentation</i> is restricted to the assignment of presentation information to an material. The <i>IfcStyledRepresentation</i> includes only presentation styles (<i>IfcCurveStyle</i>, <i>FillAreaStyle</i>, <i>IfcSurfaceStyle</i>) that define how a material should be presented within a particular (eventually view and scale dependent) representation context. All instances of <i>IfcStyledRepresentation</i> are referenced by <i>IfcMaterialDefinitionRepresentation</i>, and assigned to <i>IfcMaterial</i> by <i>IfcMaterialDefinitionRepresentation.RepresentedMaterial</i>.
</blockquote>

<p>A styled representation has to include one or several styled items with the associated style information (curve, symbol, text, fill area, or surface styles). It shall not contain the geometric representation items that are styled.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
2193;IfcShapeModel;"<EPM-HTML>

<p><i>IfcShapeModel</i> represents
the concept of a particular geometric and/or topological
representation of a product's shape or a product component's shape
within a representation context. This representation context has to
be a geometric representation context (with the exception of
topology representations without associated geometry). The two
subtypes are <i>IfcShapeRepresentation</i> to cover geometric
models that represent a shape, and <i>IfcTopologyRepresentation</i>
to cover the conectivity of a product or product component. The
topology may or may not have geometry associated.</p>

<p>The <i>IfcShapeModel</i> can be a shape representation
(geometric and/or topologogical) of a product (via
<i>IfcProductDefinitionShape</i>), or a shape representation
(geometric and/or topologogical) &nbsp;of a component of a product
shape (via <i>IfcShapeAspect</i>).</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

</EPM-HTML>"
2198;IfcShapeRepresentation;"<EPM-HTML> 

<p>The <em>IfcShapeRepresentation</em> represents the concept of a
particular geometric representation of a product or a product
component within a specific geometric representation context. The
inherited attribute <em>RepresentationType</em> is used to define
the geometric model used for the shape representation (for example, 
'SweptSolid', or 'Brep'), the inherited attribute
<em>RepresentationIdentifier</em> is used to denote the part of the
representation captured by the <em>IfcShapeRepresentation</em>
(for example, 'Axis', 'Body').</p>

<p>Several representation identifiers for shape representation are
included as predefined values for <em>RepresentationIdentifier</em>:</p>
<table cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>Box</b></td>
<td align=""left"" valign=""top"">Bounding box as simplified 3D box
geometry of an element</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>Annotation</b></td>
<td align=""left"" valign=""top"">2D annotations not representing
elements</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>Axis</b></td>
<td align=""left"" valign=""top"">2D or 3D Axis, or single line,
representation of an element</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>FootPrint</b></td>
<td align=""left"" valign=""top"">2D Foot print, or double line,
representation of an element, projected to ground view</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>Surface</b></td>
<td align=""left"" valign=""top"">3D Surface representation, e.g. of an
analytical surface, of an elementplane)</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>Body</b></td>
<td align=""left"" valign=""top"">3D Body representation, e.g. as
wireframe, surface, or solid model, of an element</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""210""><b>Lighting</b></td>
<td align=""left"" valign=""top"">Representation of emitting light as a
light source within a shape representation</td>
</tr>
</tbody>
</table>
<p>Several representation types for shape representation are
included as predefined values for <em>RepresentationType</em>:</p>
<table cellpadding=""2"" cellspacing=""2"">
<tbody>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>Curve2D</b></td>
<td align=""left"" valign=""top"">2 dimensional curve</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>Curve3D</b></td>
<td align=""left"" valign=""top"">3 dimensional curve</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>Surface2D</b></td>
<td align=""left"" valign=""top"">2 dimensional surface (a region on
ground view)</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>Surface3D</b></td>
<td align=""left"" valign=""top"">3 dimensional surface</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>GeometricSet</b></td>
<td align=""left"" valign=""top"">points, curves, surfaces (2 or 3
dimensional)</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180"">
<b>GeometricCurveSet</b></td>
<td align=""left"" valign=""top"">points, curves (2 or 3
dimensional)</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>Annotation2D</b></td>
<td>points, curves (2 or 3 dimensional), hatches and text (2
dimensional)</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>SurfaceModel</b></td>
<td align=""left"" valign=""top"">face based and shell based surface
model</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20"">
<b>SolidModel</b></td>
<td align=""left"" valign=""top"">including swept solid, Boolean
results and Brep bodies<br>
more specific types are:</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>SweptSolid</b></td>
<td align=""left"" valign=""top"">swept area solids, by extrusion and
revolution, excluding tapered sweeps</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180"">
<b>AdvancedSweptSolid</b></td>
<td align=""left"" valign=""top"">swept area solids created by sweeping
a profile along a directrix, and tapered sweeps</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>Brep</b></td>
<td align=""left"" valign=""top"">faceted Brep's with and without
voids</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>AdvancedBrep</b></td>
<td align=""left"" valign=""top"">Brep's based on advanced faces, with
b-spline surface geometry, with and without voids</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>CSG</b></td>
<td align=""left"" valign=""top"">Boolean results of operations between
solid models, half spaces and Boolean results</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>Clipping</b></td>
<td align=""left"" valign=""top"">Boolean differences between swept
area solids, half spaces and Boolean results</td>
</tr>
<tr>
<td colspan=""2"" align=""left"" valign=""top"" width=""20""><em><br>
additional types</em></td>
<td align=""left"" valign=""top""><br>
some additional representation types are provided:</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>BoundingBox</b></td>
<td align=""left"" valign=""top"">simplistic 3D representation by a
bounding box</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180"">
<b>SectionedSpine</b></td>
<td align=""left"" valign=""top"">cross section based representation of
a spine curve and planar cross sections. It can represent a surface
or a solid and the interpolations of the between the cross sections
is not defined</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180""><b>LightSource</b></td>
<td align=""left"" valign=""top"">light source with (depending on type)
position, orientation, light colour, intensity and attenuation</td>
</tr>
<tr>
<td align=""left"" valign=""top"" width=""20""></td>
<td align=""left"" valign=""top"" width=""180"">
<b>MappedRepresentation</b></td>
<td align=""left"" valign=""top"">representation based on mapped
item(s), referring to a representation map. Note: it can be seen as
an inserted block reference. The shape representation of the mapped
item has a representation type declaring the type of its
representation items.</td>
</tr>
</tbody>
</table>
<p>Table 1: string values for the inherited attribute
'<em>RepresentationType</em>'.</p>

<blockquote class=""note"">
NOTE&nbsp; The definition of this entity relates to the ISO 10303 entity shape_representation. Please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.
</blockquote>

<blockquote>
HISTORY&nbsp; New entity in IFC Release 1.5.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The <em>RepresentationType</em>'s 'Curve3D', 'Surface2D', 'Surface3D', 'AdvancedBrep', 'LightSource', and the <em>RepresentationIdentifier</em> 'Lighting' have been added.
</blockquote>

</EPM-HTML>"
2203;IfcTopologyRepresentation;"<EPM-HTML> 
<p><i>IfcTopologyRepresentation</i>
represents the concept of a particular topological representation of a
product or a product component within a representation context. This
representation context does not need to be (but may be) a geometric
representation context. Several representation types for shape
representation are included as predefined types: </p>
<table>
  <tbody>
    <tr>
      <td><b>Vertex</b></td>
      <td>topological vertex
representation (with or without assigned geometry)</td>
    </tr>
    <tr>
      <td><b>Edge</b></td>
      <td>topological edge
representation (with or without assigned geometry)</td>
    </tr>
    <tr>
      <td><b>Path</b></td>
      <td>topological path
representation (with or without assigned geometry)</td>
    </tr>
    <tr>
      <td><b>Face</b></td>
      <td>topological face
representation (with or without assigned geometry)</td>
    </tr>
    <tr>
      <td><b>Shell</b></td>
      <td>topological shell
representation (with or without assigned geometry)</td>
    </tr>
    <tr>
      <td><b>Undefined</b></td>
      <td>no constraints imposed</td>
    </tr>
  </tbody>
</table>
<p>The representation type is
given as a string value at the inherited attribute '<i>RepresentationType</i>'.<br>
</p>

<blockquote class=""history"">
HISTORY: New entity in IFC 2x2.
</blockquote>

</EPM-HTML>"
2207;IfcShapeAspect;"<EPM-HTML>
    <p>
      <u>Definition from ISO/CD 10303-41:1992</u>: The shape
      aspect is an identifiable element of the shape of a
      product.
    </p>
    <p>
      <i>IfcShapeAspect</i>
      allows for grouping of shape representation items that
      represent aspects (or components) of the shape of a
      product. Thereby shape representations of components of the
      product shape represent a distinctive part to a product
      that can be explicitly addressed.<br>
    </p>
    <blockquote class=""note"">
      NOTE&nbsp;˙The definition of
      this class relates to the ISO 10303 entity shape_aspect. Please
      refer to ISO/IS 10303-41:1994 for the final definition of
      the formal standard.
    </blockquote>
    <blockquote class=""history"">
      HISTORY&nbsp; New Entity in IFC Release 2.0
    </blockquote>
    <blockquote class=""change-ifc2x4"">
      IFC 2x4 CHANGE&nbsp; Attribute
      <i>PartOfProductDefinitionShape</i> declared OPTIONAL with 
      upward compatibility for file based exchange.
    </blockquote>
    <p>
      <u>Informal propositions:</u><br>
    </p>
    <ol>
      <li>If <i>ShapeRepresentations</i> points to shape
      representations that are part of an
      <i>IfcProductDefinitionShape</i>,
      <i>PartOfProductDefinitionShape</i> must refer to this
      instance of <i>IfcProductDefinitionShape</i>.
        <blockquote>
          <small>NOTE˙ <i>PartOfProductDefinitionShape</i> is
          only to be omitted if the shape representations are
          attached to an <i>IfcRepresentationMap</i>. ˙This
          enables the use of <i>IfcShapeAspect</i> with
          <i>IfcRepresentationMap</i>'s that are used by an
          <i>IfcTypeProduct</i> through the
          <i>RepresentationMaps</i> attribute.</small><br>
        </blockquote>
      </li>
    </ol>
</EPM-HTML>"
2213;IfcProductDefinitionShape;"<EPM-HTML>

<p>The <i>IfcProductDefinitionShape</i> defines all shape relevant information about an <i>IfcProduct</i>. It allows for multiple geometric shape representations of the same product. The shape relevant information includes:</p>
<ul>
<li>the shape representation including geometric representation items (for 3D solids, 2D annotations, etc.) and:
<ul>
<li>associated presentation information (line color, line type, surface rendering properties)</li>
<li>assignment to presentation layers (CAD layers for visibility control)</li>
</ul>
</li>
<li>or the topological representation items for connectivity systems (vertex, edge, face representations) that may include geometric representation items (vertex points, edge curves, face surfaces)</li>
</ul>

<blockquote class=""note"">
NOTE&nbsp; The definition of this entity relates to the ISO 10303 entity product_definition_shape. Please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.
</blockquote>

<blockquote>
HISTORY&nbsp; New Entity in IFC Release 1.5
</blockquote>

</EPM-HTML>"
2217;IfcProductRepresentation;"<EPM-HTML>

<p><i>IfcProductRepresentation</i> defines a representation of a
product, including its (geometric or topological) representation.
A product can have zero, one or many geometric representations,
and a single geometric representation can be shared among various
products using mapped representations.</p>

<blockquote class=""note"">
NOTE: The definition
of this entity relates to the ISO 10303 entity property_definition.
The use of the term &lsquo;property&rsquo; was avoided since it
conflicts with the property, property type, and property set
definitions elsewhere in the IFC model.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2.0
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 NOTE&nbsp;˙Users should not instantiate the entity from IFC2x Edition 3 onwards.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Entity made abstract.
</blockquote>

</EPM-HTML>"
2223;IfcMaterialDefinitionRepresentation;"<EPM-HTML>

<p><i>IfcMaterialDefinitionRepresentation</i> defines presentation information relating to <i>IfcMaterial</i>. It allows for multiple presentations of the same material for different geometric representation contexts.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcMaterialDefinitionRepresentation</i> is currently only used
to define presentation information to material used at element
occurrences, defined as subtypes of <i>IfcElement</i>, or at
element types, defined as subtypes of <i>IfcElementType</i>. The
<i>IfcMaterial</i> is assigned to the subtype of
<i>IfcElement</i>, or <i>IfcElementType</i> using the
<i>IfcRelAssociatesMaterial</i> relationship (eventually via
other material related entities <i>IfcMaterialLayerSetUsage</i>,
<i>IfcMaterialLayerSet</i>, <i>IfcMaterialLayer</i>, or
<i>IfcMaterialProfileSetUsage</i>, <i>IfcMaterialProfileSet</i>,
<i>IfcMaterialProfile</i>).
</blockquote>

<p>The <i>IfcMaterialDefinitionRepresentation</i> can apply</p>
<ul>
<li>different presentation styles for different representation contexts, for example, a different style for sketch view, model view or plan view, or for different target scales,</li>
<li>for each representation context is can apply curve style, fill area style (hatching), symbol, text and surface style.</li>
</ul>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The entity <i>IfcMaterialDefinitionRepresentation</i> has been added. Upward compatibility for file based exchange is guaranteed.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The assignment of curve, surface and other styles to an <i>IfcStyledItem</i> has been simplified by <i>IfcStyleAssignmentSelect</i>. The use of intermediate <i>IfcPresentationStyleAssignment</i> is deprecated.
</blockquote>

<p class=""use-head"">Use definition</p>

<p>As shown in Figure 331, the presentation assignment can be specific to a representation context by adding one and more <i>IfcStyledRepresentation</i>'s. Each of them includes a single <i>IfcStyledItem</i> with exactly zero or one style for either curve, fill area, surface, text or symbol style that is applicable.</p>

<table border=""0"" cellpadding=""0"" cellspacing=""0"" summary=""use diagram"">
<tr><td valign=""top""><img src=""figures/IfcMaterialDefinitionRepresentation_01.png"" alt=""use diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 331 &mdash; Material definition representation</p></td></tr>
</table>

</EPM-HTML>"
2226;IfcGeometricRepresentationSubContext;"<EPM-HTML>

<p><i>IfcGeometricRepresentationSubContext</i> defines the context that applies to several shape representations of a product being a sub context, sharing the <i>WorldCoordinateSystem</i>, <i>CoordinateSpaceDimension</i>, <i>Precision</i> and <i>TrueNorth</i> attributes with the parent <i>IfcGeometricRepresentationContext</i>.</p>

<p>The <i>IfcGeometricRepresentationSubContext</i> is used to define semantically distinguished representation types for different information content, dependent on the representation view and the target scale. It can be used to control the level of detail of the shape representation that is most applicable to this geometric representation context. addition the sub context is used to control the later appearance of the <i>IfcShapeRepresentation</i> within a plot view.</p>

<blockquote class=""note"">
NOTE&nbsp; If the <i>IfcShapeRepresentation</i> using this sub context has<i> IfcStyledItem</i>'s assigned to the <i>Items</i>, the presentation style information (e.g. <i>IfcCurveStyle</i>, <i>IfcTextStyle</i>) associated with the <i>IfcStyledItem</i> is given in target plot dimensions. For example, a line thickness (<i>IfcCurveStyle.CurveWidth</i>) is given by a thickness measure relating to the thickness for a plot within the (range of) target scale.
</blockquote>

<p>Each <i>IfcProduct</i> can then have several instances of subtypes of <i>IfcRepresentation</i>, each being assigned to a different geometric representation context (<i>IfcGeometricRepresentationContext</i> or <i>IfcGeometricRepresentationSubContext</i>). The application can then choose the most appropriate representation for showing the geometric shape of the product, depending on the target view and scale.</p>

<blockquote class=""note"">
NOTE&nbsp; The provision of a model view (<i>IfcGeometricRepresentationContext.ContextType</i> = 'Model') is mandatory. Instances of <i>IfcGeometricRepresentationSubContext</i> relate to it as its <i>ParentContext</i>.
</blockquote>

<blockquote class=""example"">
EXAMPLE&nbsp; Instances of <i>IfcGeometricRepresentationSubContext</i> can be used to handle the multi-view blocks or macros, which are used in CAD programs to store several scale and/or view dependent geometric representations of the same object.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC 2x2.
</blockquote>

</EPM-HTML>"
2258;IfcCoordinateReferenceSystem;"<EPM-HTML>

<p><u>Definition from OpenGIS&reg; Abstract Specification, Topic
2</u>: A coordinate reference system is a coordinate system which
is related to the real world by a datum. The coordinate system is
composed of a set of coordinate axes with specified units of
measure. The datum specifies the relationship of a coordinate
system to the earth. The resulting combination of coordinate
system and datum is a coordinate reference system.</p>

<p><i>IfcCoordinateReferenceSystem</i> is a definition of a coordinate
reference system by means of qualified identifiers only. The
interpretation of the identifier is expected to be well-known to
the receiving software.</p>

<blockquote class=""note"">
NOTE&nbsp; One widely-used, publicly-available
authority is the European Petroleum Survey Group (EPSG), and use
of this authority is currently specified in several OGC
Implementation Specifications. Software used to transport IFC
engineering models into GIS applications (and vice versa) is
expected to have knowledge about the OGC Implementation
Specifications.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
2264;IfcProjectedCRS;"<EPM-HTML>

    <p><u>Definition from OpenGIS&reg; Abstract Specification,
      Topic 2:</u> A 2D (or with vertical coordinate axis 3D)
      coordinate reference system used to approximate the shape
      of the earth on a planar surface, but in such a way that
      the distortion that is inherent to the approximation is
      carefully controlled and known. Distortion correction is
      commonly applied to calculated bearings and distances to
      produce values that are a close match to actual field
      values.</p>
    <p><i>IfcProjectedCRS</i> is a coordinate reference system of
      the map to which the map translation of the local
      engineering coordinate system of the construction or
      facility engineering project relates. The
      <i>MapProjection</i> and <i>MapZone</i> attributes uniquely
      identify the projection to the underlying geographic
      coordinate reference system, provided that they are
      well-known in the receiving application.</p>
    <p>The projected coordinate reference system is assumed to be
      a 2D or 3D right-handed Cartesian coordinate system, the
      optional <i>MapUnit</i> attribute can be used determine the
      length unit used by the map.</p>

    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC2x4.
    </blockquote>

</EPM-HTML>"
2269;IfcCoordinateOperation;"<EPM-HTML>
    <p>
      <u>Definition from OpenGIS&reg; Abstract Specification,
      Topic 2:</u> If the relationship between any two coordinate
      reference systems is known, coordinates can be transformed
      or converted to another coordinate reference system.
      Coordinate operations are divided into two subtypes:
    </p>
    <ul>
      <li>
        <i>Coordinate conversion</i> &ndash; mathematical
        operation on coordinates that does not include any change
        of datum. The best-known example of a coordinate
        conversion is a map projection. The parameters describing
        coordinate conversions are defined rather than
        empirically derived. Note that some conversions have no
        parameters.
      </li>
      <li>
        <i>Coordinate transformation</i> &ndash; mathematical
        operation on coordinates that usually includes a change
        of datum. The parameters of a coordinate transformation
        are empirically derived from data containing the
        coordinates of a series of points in both coordinate
        reference systems. This computational process is usually
        &lsquo;over-determined&rsquo;, allowing derivation of
        error (or accuracy) estimates for the transformation.
        Also, the stochastic nature of the parameters may result
        in multiple (different) versions of the same coordinate
        transformation. Because of this several transformations
        may exist for a given pair of coordinate reference
        systems, differing in their transformation method,
        parameter values and accuracy characteristics.
      </li>
    </ul>
    <p>
      The coordinate operation is an
      abstract supertype to handle any operation (transformation
      or conversion) between two coordinate reference systems. It
      is meant to provide expandability for future versions,
      since currently only the conversion of a local engineering
      coordinate system into a map coordinate reference system is
      dealt with by the subtype <i>IfcMapConversion</i>.
    </p>
    <p>
      By convention, a coordinate operation is given between the
      <i>SourceCRS</i> being the more local, or child coordinate
      reference system, and the <i>TargetCRS</i> being the more
      remote or parent coordinate reference system, in
      the˙special case the coordinate operation between the local
      engineering coordinate system of the construction project
      and any map or other coordinate reference system.
    </p>
    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC2x4.
    </blockquote>
</EPM-HTML>"
2273;IfcMapConversion;"<EPM-HTML>

<p>The map conversion deals with transforming the local engineering coordinate system, often called world coordinate system, into the coordinate reference system of the underlying map.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcMapConversion</i> does not handle the projection of a map from the geodetic coordinate reference system.
</blockquote>

<p>The map conversion allows to convert the local origin of the local engineering coordinate system to its place within a map (easting, northing, orthogonal height) and to rotate the x-axis of the local engineering coordinate system within the horizontal (easting/westing) plane of the map.</p>

<blockquote class=""note"">
NOTE&nbsp; The z axis of the local engineering coordinate system is always parallel to the z axis of the map coordinate system.
</blockquote>

<p>The scale factor can be used when the length unit for the 3 axes of the map coordinate system are not identical with the length unit established for this project (see˙<i>IfcProject.UnitsInContext</i>), if omitted, the scale factor 1.0 is assumed.</p>

<blockquote>
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
2281;IfcStructuralLoadOrResult;"<EPM-HTML>

<p><u>Definition from IAI:</u> Abstract superclass of simple load or result classes.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New abstract superclass in IFC 2x4, upwards compatibility of all subtypes is preserved.</font></blockquote>

</EPM-HTML>"
2284;IfcStructuralLoad;"<EPM-HTML>

<p><u>Definition from IAI:</u> The abstract entity <i>IfcStructuralLoadOrResult</i> is the supertype of all loads (actions or reactions) or of certain requirements resulting from structural analysis, or certain provisions which influence structural analysis.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2288;IfcStructuralLoadConfiguration;"<EPM-HTML>

<p><u>Definition from IAI:</u> This class combines one or more load or result values in a 1- or 2-dimensional configuration.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

<p><u>Informal propositions</u>:</p>

<ol>
  <li>All items in <i>Values</i> shall be of the same type.</li>
  <li>If the loads or results comprise a curve activity, 1-dimensional locations shall be given, measured locally along the curve.  The location shall not exceed the bounds of the curve actvity.  The load samples and corresponding locations shall be given in ascending order of locations.</li>
  <li>If the loads or results comprise a surface activity, 2-dimensional locations shall be given, measured in the surface activity's local x and y directions.  The location shall not exceed the bounds of the surface activity.</li>
</ol>

<blockquote><font size=""-1"">NOTE&nbsp; There are no ordering requirements in the 2-dimensional case, but the 1-dimensional case shall be spatially ordered for simplicity.</font></blockquote>

</EPM-HTML>"
2293;IfcStructuralLoadStatic;"<EPM-HTML>

<p><u>Definition from IAI:</u> The abstract entity <i>IfcStructuralLoadStatic</i> is the supertype of all static loads (actions or reactions) which can be defined.  Within scope are single i.e. concentrated forces and moments, linear i.e. one-dimensionally distributed forces and moments, planar i.e. two-dimensionally distributed forces, furthermore displacements and temperature loads.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2299;IfcStructuralLoadSingleForce;"<EPM-HTML>

	 <P><U>Definition from IAI:</U> Instances of the entity
		<I>IfcStructuralLoadSingleForce</I> shall be used to define the forces and
		moments of an action operating on a single point. </P>
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1""> HISTORY: New entity in Release IFC2x
		  edition 2. </FONT></P> </BLOCKQUOTE>

</EPM-HTML>"
2307;IfcStructuralLoadSingleForceWarping;"<EPM-HTML>

	 <P><U>Definition from IAI:</U> Instances of the entity
		<I>IfcStructuralLoadSingleForceWarping</I>, as a subtype of
		<I>IfcStructuralLoadSingleForce</I>, shall be used to define an action operation
		on a single point. In addition to forces and moments defined by its supertype a
		warping moment can be defined. </P> 
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1""> HISTORY: New entity in Release IFC2x
		  edition 2. </FONT></P> </BLOCKQUOTE>

</EPM-HTML>"
2309;IfcStructuralLoadLinearForce;"<EPM-HTML>

	 <P><U>Definition from IAI:</U> An instance of the entity
		<I>IfcStructuralLoadLinearForce</I> shall be used to define actions on curves.
		</P>
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1""> HISTORY: New entity in Release IFC2x
		  edition 2. </FONT></P> </BLOCKQUOTE>

</EPM-HTML>"
2316;IfcStructuralLoadPlanarForce;"<EPM-HTML>

	 <P><U>Definition from IAI:</U> An instance of the entity
		<I>IfcStructuralLoadPlanarForce</I> shall be used to define actions on faces.
		</P> 
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1"">HISTORY: New entity in Release IFC2x
		  edition 2. </FONT></P> </BLOCKQUOTE>

</EPM-HTML>"
2320;IfcStructuralLoadSingleDisplacement;"<EPM-HTML>

	 <P><U>Definition from IAI:</U> Instances of the entity
		<I>IfcStructuralLoadSingleDisplacement</I> shall be used to define displacements.</P>
	 <BLOCKQUOTE> 
		<P><FONT COLOR=""#0000FF"" SIZE=""-1""> HISTORY: New entity in Release IFC2x
		  edition 2. </FONT></P> </BLOCKQUOTE>

</EPM-HTML>"
2328;IfcStructuralLoadSingleDisplacementDistortion;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines a displacement with warping.</p>

<blockquote><font color=""#0000ff"" size=""-1""> HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2330;IfcStructuralLoadTemperature;"<EPM-HTML>

<p>An instance of the entity <i>IfcStructuralLoadTemperature</i> shall be used to define actions which are caused by a temperature change. As shown in Figure 332, the change of temperature is given with a constant value which is applied to the complete section and values for temperature differences between outer fibres of the section.</p>

<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x2.</blockquote> 

<table>
<tr><td><img SRC=""figures/StructuralLoadTemperature.gif"" WIDTH=""323"" HEIGHT=""186"" BORDER=""0"" ALIGN=""LEFT""></td></tr>
<tr><td><p class=""figure"">Figure 332 &mdash; Structural load temperature</p></td></tr>
</table>

</EPM-HTML>"
2334;IfcSurfaceReinforcementArea;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes required or provided reinforcement area of surface members.</p>

<blockquote><font size=""-1"">NOTE&nbsp; Member design parameters like concrete cover, effective depth, orientation of meshes or rebars (two, optionally three directions) etc. are not specified in <i>IfcStructuralLoadResource</i> schema.  They shall be specified at the level of structural members.</font></blockquote>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x4.</font></blockquote>

</EPM-HTML>"
2342;IfcBoundaryCondition;"<EPM-HTML>
<p><u>Definition
from IAI:</u> The abstract entity <i>IfcBoundaryCondition</i>
is the supertype of all boundary conditions that can be applied to
structural connection definitions, either directly for the connection
(e.g. the joint) or for the relation between a structural member and
the connection.</p>
<blockquote><font
 size=""-1"">NOTE: The boundary conditions are used
within other parts, mainly by instances of <i>IfcStructuralConnection</i>
(for the definition of supports) and instances of <i>IfcRelConnectsStructuralMember</i>
(for the definition of connections between structural members and
structural connections). </font></blockquote>
<blockquote>
  <p><font
 color=""#0000ff"" size=""-1"">HISTORY: New entity
in Release IFC2x Edition
2. </font></p>
</blockquote>
</EPM-HTML>"
2347;IfcBoundaryNodeCondition;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes linearly elastic support conditions or connection conditions.</p>

<p>Applicability:</p>
<ul>
  <li>Point supports and connections.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change: Attributes <i>LinearStiffnessX/Y/Z</i> renamed to <i>TranslationalStiffnessX/Y/Z</i>.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change: All attribute data types changed from numeric to SELECT between Boolean and numeric.  Stiffnesses may now also be negative, for example to capture destabilizing effects in boundary conditions.  The IFC 2x3 convention of -1. representing infinite stiffness is no longer valid and must not be used.  Infinite stiffness, i.e. fixed supports, are now modeled by the Boolean value TRUE.</font></blockquote>

</EPM-HTML>"
2355;IfcBoundaryNodeConditionWarping;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes linearly elastic support conditions or connection conditions, including linearly elastic warping restraints.</p>

<p>Applicability:</p>
<ul>
  <li>Point supports and connections.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote> 

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change: All attribute data types changed from numeric to SELECT between Boolean and numeric.  Stiffnesses may now also be negative, for example to capture destabilizing effects in boundary conditions.  The IFC 2x3 convention of -1. representing infinite stiffness is no longer valid and must not be used.  Infinite stiffness, i.e. fixed supports, are now modeled by the Boolean value TRUE.</font></blockquote>

</EPM-HTML>"
2366;IfcBoundaryEdgeCondition;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes linearly elastic support conditions or connection conditions.</p>

<p>Applicability:</p>
<ul>
  <li>Curve supports and connections.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change: Attributes <i>LinearStiffnessX/Y/Z</i> renamed to <i>TranslationalStiffnessX/Y/Z</i>.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change: All attribute data types changed from numeric to SELECT between Boolean and numeric.  Stiffnesses may now also be negative, for example to capture destabilizing effects in boundary conditions.  The IFC 2x3 convention of -1. representing infinite stiffness is no longer valid and must not be used.  Infinite stiffness, i.e. fixed supports, are now modeled by the Boolean value TRUE.</font></blockquote>

</EPM-HTML>"
2379;IfcBoundaryFaceCondition;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes linearly elastic support conditions or connection conditions.</p>

<p>Applicability:</p>
<ul>
  <li>Surface supports and connections.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.<br>
IFC 2x4 change: Attributes <i>LinearStiffnessX/Y/Z</i> renamed to <i>TranslationalStiffnessX/Y/Z</i>.</font></blockquote>

<blockquote><font color=""#ff0000"" size=""-1"">IFC 2x4 change: All attribute data types changed from numeric to SELECT between Boolean and numeric.  Stiffnesses may now also be negative, for example to capture destabilizing effects in boundary conditions.  The IFC 2x3 convention of -1. representing infinite stiffness is no longer valid and must not be used.  Infinite stiffness, i.e. fixed supports, are now modeled by the Boolean value TRUE.</font></blockquote>

</EPM-HTML>"
2386;IfcSlippageConnectionCondition;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describes slippage in support conditions or connection conditions.  Slippage means that a relative displacement may occur in a support or connection before support or connection reactions are awoken.</p>

<p>Applicability:</p>
<ul>
  <li>Point supports and connections,</li>
  <li>curve supports and connections,</li>
  <li>surface supports and connections.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2390;IfcStructuralConnectionCondition;"<EPM-HTML>

<p><u>Definition from IAI:</u> Describe more rarely needed connection properties.</p>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2394;IfcFailureConnectionCondition;"<EPM-HTML>

<p><u>Definition from IAI:</u> Defines forces at which a support or connection fails.</p>

<p>Applicability:</p>
<ul>
  <li>Point supports and connections.</li>
</ul>

<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC 2x2.</font></blockquote>

</EPM-HTML>"
2402;IfcClosedShell;"<EPM-HTML> 
	 <p><u>Definition from ISO/CD 10303-42:1992</u>: A closed shell is a shell
		of the dimensionality 2 which typically serves as a bound for a region in R3. A
		closed shell has no boundary, and has non-zero finite extent. If the shell has
		a domain with coordinate space R3, it divides that space into two connected
		regions, one finite and the other infinite. In this case, the topological
		normal of the shell is defined as being directed from the finite to the
		infinite region. </p> 
	 <p>The shell is represented by a collection of faces. The domain of the
		shell, if present, contains all those faces, together with their bounds.
		Associated with each face in the shell is a logical value which indicates
		whether the face normal agrees with (TRUE) or is opposed to (FALSE) the shell
		normal. The logical value can be applied directly as a BOOLEAN attribute of an
		oriented face, or be defaulted to TRUE if the shell boundary attribute member
		is a face without the orientation attribute. </p> 
	 <p>The combinatorial restrictions on closed shells and geometrical
		restrictions on their domains are designed to ensure that any domain associated
		with a closed shell is a closed, orientable manifold. The domain of a closed
		shell, if present, is a connected, closed, oriented 2-manifold. It is always
		topologically equivalent to an <i>H</i>-fold torus for some <i>H</i>
		<FONT FACE=""Symbol"">&sup3;</FONT> 0. The number <i>H</i> is referred to as the
		surface genus of the shell. If a shell of genus <i>H</i> has a domain within
		coordinate space <i>R<sup>3</sup></i>, then the finite region of space inside
		it is topologically equivalent to a solid ball with <i>H</i> tunnels drilled
		through it.</p> 
	 <p>The Euler equation (7) applies with <i>B</i>=0, because in this case
		there are no holes. As in the case of open shells, the surface genus <i>H</i>
		may not be known a priori, but shall be an integer <FONT
		FACE=""Symbol"">&sup3;</FONT> 0. Thus a necessary, but not sufficient, condition
		for a well-formed closed shell is the following:</p> 
	 <blockquote><blockquote><p><img src=""figures/IfcOpenShell-Math1.gif"" width=""240"" height=""18""></p></blockquote></blockquote> 
	 <p>In the current IFC Release only poly loops
		(<i>IfcPolyLoop</i>) are defined for bounds of face bound
		(<i>IfcFaceBound</i>). This will allow for faceted B-rep only.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: closed_shell, please refer to ISO/IS 10303-42:1994, p.149 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history""> 
HISTORY&nbsp; New class in IFC Release 1.0
</blockquote> 

	 <p><u>Informal propositions</u>:</p> 
	 <ol> 
		<li>Every edge shall be referenced exactly twice by the loops of the face. </li> 
		<li>Each oriented edge shall be unique. </li> 
		<li>No edge shall be referenced by more than two faces. </li> 
		<li>Distinct faces of the shell do not intersect, but may share edges or vertices. </li> 
		<li>Distinct edges do not intersect but may share vertices. </li> 
		<li>Each face reference shall be unique. </li> 
		<li>The loops of the shell shall not be a mixture of poly loop and other loop types. Note: this is given, since only poly loop is defined as face bound definition.</li> 
		<li>The closed shell shall be an oriented arcwise connected 2-manifold.</li> 
		<li>The Euler equation shall be satisfied. Note: Please refer to ISO/IS
		  10303-42:1994, p.149 for the equation.</li> 
	 </ol> 
</EPM-HTML>
"
2403;IfcConnectedFaceSet;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A connected_face_set is a set of faces such that the domain of faces together with their bounding edges and vertices is connected. </p> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: connected_face_set, the subtype closed_shell is included as <I>IfcClosedShell</I> and the subtype open_shell is included as <I>IfcOpenShell</I>. Please refer to ISO/IS 10303-42:1994, p. 144 for the final definition of the formal standard.
</blockquote>
		
<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 1.0
</blockquote> 

<p>Informal proposition:</p> 
<ol> 
<li>The union of the domains of the faces and their bounding loops shall be arcwise connected.</li> 
</ol>

</EPM-HTML>"
2407;IfcTopologicalRepresentationItem;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: The topological representation item is the supertype for all the topological representation items in the geometry resource.</p> 

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: topological_representation_item. Please refer to ISO/IS 10303-42:1994, p.129 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.5
</blockquote>

</EPM-HTML>"
2415;IfcEdge;"<EPM-HTML> 
<p><u>Definition from ISO/CD 10303-42:1992</u>: An edge is the
topological construct corresponding to the connection of two
vertices. More abstractly, it may stand for a logical
relationship between two vertices. The domain of an edge, if
present, is a finite, non-self-intersecting open curve in
<i>R<sup>M</sup></i>, that is, a connected 1-dimensional
manifold. The bounds of an edge are two vertices, which need not
be distinct. The edge is oriented by choosing its traversal
direction to run from the first to the second vertex. If the two
vertices are the same, the edge is a self loop. The domain of the
edge does not include its bounds, and 0 &le; &Xi; &le; &infin;.
Associated with an edge may be a geometric curve to locate the
edge in a coordinate space; this is represented by the edge curve
(<i>IfcEdgeCurve</i>) subtype. The curve shall be finite and
non-self-intersecting within the domain of the edge. An edge is a
graph, so its multiplicity M and graph genus <i>G<sup>e</sup></i>
may be determined by the graph traversal algorithm. Since
<i>M</i> = <i>E</i> = 1, the Euler equation (1) reduces in the
case to</p>
<blockquote>
<p><img src=""figures/IfcEdge-Math1.gif"" width=""105"" height=
""24""></p>
</blockquote>
<p>where <i>V</i> = 1 or 2, and <i>G<sup>e</sup></i> = 1 or 0.
Specifically, the topological edge defining data shall
satisfy:</p>
<dl>
<dd>- an edge has two vertices
<dl>
<dd><img src=""figures/IfcEdge-Math2.gif"" width=""64"" height=
""26""></dd>
</dl>
</dd>
<dd>- the vertices need not be distinct
<dl>
<dd><img src=""figures/IfcEdge-Math3.gif"" width=""88"" height=
""26""></dd>
</dl>
</dd>
<dd>- Equation (2) shall hold.
<dl>
<dd><img src=""figures/IfcEdge-Math4.gif"" width=""120"" height=
""26""></dd>
</dl>
</dd>
</dl>
<p>The geometry between the two
vertices defaults to a straight line if no curve geometry is
assigned using the subtype <i>IfcEdgeCurve</i>. The
<i>IfcEdge</i> can therefore be used to exchange straight edges
without an associated geometry provided by <i>IfcLine</i> or
<i>IfcPolyline</i> thought <i>IfcEdgeCurve.EdgeGeometry</i>.</p>

<p>Figure 333 illustrates an example where the bounds of the <i>IfcEdge</i> are given by the <i>EdgeStart</i> and <i>EdgeEnd</i>; this also determines the direction of the edge. The location within a coordinate space is determined by the <i>IfcVertexPoint</i> type for <i>EdgeStart</i> and <i>EdgeEnd</i>. Since no edge geometry is assigned, it defaults to a straight line agreeing to the direction sense.</p>

<table>
<tr><td><img src=""figures/IfcEdge.png"" alt=""edge representation"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 333 &mdash; Edge representation</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: edge. Please refer to ISO/IS 10303-42:1994, p. 130 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2.0
</blockquote>

<p><u>Informal propositions:</u></p>
<ol>
<li>The edge has dimensionality 1.</li>
<li>The extend of an edge shall be finite and nonzero.</li>
</ol>

</EPM-HTML>"
2421;IfcOrientedEdge;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</U>: An oriented edge is an edge constructed from another edge and contains a BOOLEAN direction flag to indicate whether or not the orientation of the constructed edge agrees with the orientation of the original edge. Except for perhaps orientation, the oriented edge is equivalent to the original edge. </p> 

<blockquote class=""note""> 
NOTE&nbsp; A common practice is solid modelling systems is to have an entity that represents the ""use"" or ""traversal"" of an edge. This ""use"" entity explicitly represents the requirement in a manifold solid that each edge must be traversed exactly twice, once in each direction. The ""use"" functionality is provided by the edge subtype oriented edge.
</blockquote> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: oriented_edge. Please refer to ISO/IS 10303-42:1994, p. 133 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2.0.
</blockquote> 

</EPM-HTML>"
2427;IfcVertex;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A vertex is the topological construct corresponding to a point. It has dimensionality 0 and extent 0. The domain of a vertex, if present, is a point in m dimensional real space <i>R<sup>M</sup></i>; this is represented by the vertex point subtype.</p> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: vertex. Please refer to ISO/IS 10303-42:1994, p. 129 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2.0
</blockquote> 

<p><u>Informal proposition</u>:</p>
<ol>
<li>The vertex has dimensionality 0. This is a fundamental property of the vertex.</li>
<li>The extent of a vertex is defined to be zero.</li>
</ol>

</EPM-HTML>"
2429;IfcVertexPoint;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A vertex point is a vertex which has its geometry defined as a point. </p> 

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: vertex_point. Please refer to ISO/IS 10303-42:1994, p. 130 for the final definition of the formal standard. Due to the general IFC model specification rule not to use multiple inheritance, the subtype relationship to geometric_representation_item is not included.
</blockquote> 

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2x.
</blockquote> 

<p><u>Informal proposition</u>:</p> 
<ol> 
	<li>The domain of the vertex is formally defined to be the domain of its vertex point.</li> 
</ol> 

</EDM-HTML>"
2431;IfcEdgeCurve;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: An edge curve is
a special subtype of edge which has its geometry fully defined.
The geometry is defined by associating the edge with a curve
which may be unbounded. As the topological and geometric
directions may be opposed, an indicator (same sense) is used to
identify whether the edge and curve directions agree or are
opposed. The Boolean value indicates whether the curve direction
agrees with (TRUE) or is in the opposite direction (FALSE) to the
edge direction. Any geometry associated with the vertices of the
edge shall be consistent with the edge geometry. Multiple edges
can reference the same curve.</p>

<p>Figure 334 illustrates an example where the edge geometry is given by an unbounded curve, here <i>IfcCircle</i>. The bounds are provided by the <i>EdgeStart</i> and <i>EdgeEnd</i>, the topological direction of the <i>IfcEdgeCurve</i> opposes the direction of the <i>IfcCircle</i> by <i>SameSense</i> = FALSE.</p>

<table>
<tr><td><img alt=""example"" src=""figures/IfcEdgeCurve.png"" width=""600"" height=""220""></td></tr>
<tr><td><p class=""figure"">Figure 334 &mdash; Edge curve</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: edge_curve. Please refer to ISO/IS 10303-42:1994, p. 132
for the final definition of the formal standard. Due to the general IFC model specification rule not to use multiple inheritance, the subtype relationship to geometric_representation_item is not included.
</blockquote>

<blockquote class=""history""
HISTORY&nbsp; New Entity in IFC2x.
</blockquote>

<p><u>Informal propositions</u>:</p>
<ol>
<li>The domain of the edge curve is formally defined to be the
domain of its edge geometry as trimmed by the vertices. This
domain does not include the vertices.</li>
<li>An edge curve has non-zero finite extent.</li>
<li>An edge curve is a manifold.</li>
<li>An edge curve is arcwise connected.</li>
<li>The edge start is not a part of the edge domain.</li>
<li>The edge end is not a part of the edge domain.</li>
<li>Vertex geometry shall be consistent with edge geometry.</li>
</ol>

</EPM-HTML>"
2434;IfcSubedge;"<EPM-HTML>

<p><u>Definition from ISO/DIS 10303-42:1999(E)</U>: A subedge is an edge whose domain is a connected portion of the domain of an existing edge. The topological constraints on a subedge are the same as those on an edge.</p> 

<p>Informal propositions:</p> 
<ol> 
<li>The domain of the subedge is formally defined to be the domain of the parent edge, as trimmed by the subedge start vertex and subedge end vertex.</li> 
<li>The start vertex and end vertex shall be within the union of the domains of the vertices of the parent edge and the domain of the <i>parent edge</i>.</li> 
</ol> 

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: subedge. Please refer to ISO/DIS 10303-42:1999(E), p. 194 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
2436;IfcFace;"<EPM-HTML> 
	 <p><u>Definition from ISO/CD 10303-42:1992</u>: A face is a topological
		entity of dimensionality 2 corresponding to the intuitive notion of a piece of
		surface bounded by loops. Its domain, if present, is an oriented, connected,
		finite 2-manifold in <i>R<sup>m</sup></i>. A face domain shall not have handles
		but it may have holes, each hole bounded by a loop. The domain of the
		underlying geometry of the face, if present, does not contain its bounds, and 0
		&lt; &Xi; &lt; &infin;.</p> 
	 <p>A face is represented by its bounding loops, which are defined as face
		bounds. A face has a topological normal n and the tangent to a loop is t. For a
		loop bounding a face with defined geometry, the cross product n x t points
		toward the interior of the face. That is, each loop runs counter-clockwise
		around the face when viewed from above, if we consider the normal n to point
		up. With each loop is associated a BOOLEAN flag to signify whether the loop
		direction is oriented with respect to the face normal (TRUE) or should be
		reversed (FALSE). </p> 
	 <p>A face shall have at least one bound, and the loops shall not intersect.
		One loop is optionally distinguished as the outer loop of the face. If so, it
		establishes a preferred way of embedding the face domain in the plane, in which
		the other bounding loops of the face are inside the outer bound. Because the
		face domain is arcwise connected, no inner loop will contain any other loop.
		This is true regardless of which embedding in the plane is chosen. </p> 
	 <p>The edges and vertices referenced by the loops of a face form a graph,
		of which the individual loops are the connected components. The Euler equation
		(1) for this graph becomes:</p> 
	 <blockquote> 
		<blockquote> 
		  <p><img src=""figures/IfcFace-Math1.gif"" width=""176"" height=""48""></p></blockquote></blockquote> 
	 <p>where <i>G<sup>l</sup><sub>i</sub></i> is the graph genus of the<i>
		i</i> <sup>th</sup> loop.</p> 
	 <blockquote class=""note""> 
		NOTE&nbsp; Corresponding ISO 10303 entity: face. No subtypes of face have been incorporated
		  into this IFC Release. Please refer to ISO/IS 10303-42:1994, p. 140 for the
		  final definition of the formal standard. The WR1 has not been incorporated,
		  since it is always satisfied, due to the fact that only poly loops exist for
		  face bounds.
         </blockquote>
         <blockquote class=""history"">
		HISTORY&nbsp; New class in IFC Release 1.0
         </blockquote> 
	 <p><u>Informal propositions</u>:</p> 
	 <ol> 
		<li>No edge shall be referenced by the face more than twice. </li> 
		<li>Distinct face bounds of the face shall have no common vertices. </li>
		<li>If geometry is present, distinct loops of the same face shall not
		  intersect. </li> 
		<li>The face shall satisfy the Euler Equation: (number of vertices) -
		  (number of edges) - (number of loops) + (sum of genus for loops) = 0.</li> 
	 </ol> 
</EPM-HTML>"
2440;IfcFaceSurface;"<EPM-HTML>
	 <p><u>Definition from ISO/CD 10303-42:1992</u>: A face surface
		(<i>IfcFaceSurface</i>) is a subtype of face in which the geometry is defined by an
		associated surface. The portion of the surface used by the face shall be
		embeddable in the plane as an open disk, possibly with holes. However, the
		union of the face with the edges and vertices of its bounding loops need not be
		embeddable in the plane. It may, for example, cover an entire sphere or torus.
		As both a face and a geometric surface have defined normal directions, a
		BOOLEAN flag (the orientation attribute) is used to indicate whether the
		surface normal agrees with (TRUE) or is opposed to (FALSE) the face normal
		direction. The geometry associated with any component of the loops of the face
		shall be consistent with the surface geometry, in the sense that the domains of
		all the vertex points and edge curves are contained in the face geometry
		surface. A surface may be referenced by more than one face surface.</p> 
	 <blockquote class=""note""> 
		NOTE&nbsp; Corresponding ISO 10303 entity:
		  face_surface. Please refer to ISO/IS 10303-42:1994, p. 204 for the final
		  definition of the formal standard. Due to the general IFC model specification
		  rule not to use multiple inheritance, the subtype relationship to
		  geometric_representation_item is not included.
         </blockquote>
         <blockquote class=""history"">
		HISTORY&nbsp; New class in IFC2x
         </blockquote> 
	 <p><u>Informal propositions</u>:</p> 
	 <ol> 
		<li>The domain of the face surface is formally defined to be the domain
		  of its face geometry as trimmed by the loops, this domain does not include the
		  bounding loops.</li> 
		<li>A face surface has non zero finite extent.</li> 
		<li>A face surface is a manifold.</li> 
		<li>A face surface is arcwise connected.</li> 
		<li>A face surface has surface genus 0.</li>
		<li>The loops are not part of the face domain.</li>
		<li>Loop geometry shall be consistent with face geometry. This implies
		  that any edge - curves or vertex points used in defining the loops bounding the
		  face surface shall lie on the face geometry.</li>
		<li>The loops of the face shall not intersect.</li>
	 </ol> 
</EPM-HTML>"
2444;IfcAdvancedFace;"<EPM-HTML>

<p>An advanced face is a specialization of a face surface that has to meet requirements on using particular topological and geometric representation items for the definition of the faces, edges and vertices.</p>

<p>An <i>IfcAdvancedFace</i> is restricted to:</p>
<ul>
<li>have a face surface geometry of type <i>IfcElementarySurface</i>, <i>IfcSweptSurface</i> or <i>IfcBSplineSurface</i></li>
<li>have at least on <i>IfcFaceOuterBound</i> as the bound of the face</li>
<li>have all faces to be bound by <i>IfcEdgeLoop</i> or <i>IfcVertexLoop</i></li>
<li>have all edges to have an edge curve geometry</li> <li>have the edge curve geometry restricted to <i>IfcLine</i>, <i>IfcConic</i>, <i>IfcPolyline</i>, or <i>IfcBSplineCurve</i></li>
</ul>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: advanced_face. Please refer to ISO/IS 10303-511:1999 for
the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4
</blockquote>

</EPM-HTML>"
2448;IfcFaceBound;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A face bound is a loop which is intended to be used for bounding a face. </p> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: face_bound. Please refer to ISO/IS 10303-42:1994, p. 139 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 1.0
</blockquote> 

</EPM-HTML>"
2452;IfcFaceOuterBound;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992:</u> A face outer bound is a special subtype of face bound which carries the additional semantics of defining an outer boundary on the face. No more than one boundary of a face shall be of this type. </p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 entity: face_outer_bound. Please refer to ISO/IS 10303-42:1994, p. 139 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.0
</blockquote> 

</EPM-HTML>"
2453;IfcLoop;"<EPM-HTML>
	 <p><u>Definition from ISO/CD 10303-42:1992:</u> A loop is a topological
		entity constructed from a single vertex, or by stringing together connected
		(oriented) edges, or linear segments beginning and ending at the same vertex.
		It is typically used to bound a face lying on a surface. A loop has
		dimensionality of 0 or 1. The domain of a 0-dimensional loop is a single point.
		The domain of a 1-dimensional loop is a connected, oriented curve, but need not
		to be manifold. As the loop is a circle, the location of its beginning/ending
		point is arbitrary. The domain of the loop includes its bounds, an 0 &le; &Xi;
		&lt; &infin;. </p> 
	 <p>A loop is represented by a single vertex, or by an ordered collection of
		oriented edges, or by an ordered collection of points. A loop is a graph, so
		<i>M</i> and the graph genus <i>G<sup>l</sup></i> may be determined by the
		graph traversal algorithm. Since <i>M</i> = 1, the Euler equation (1) reduces
		in this case to </p> 
	 <blockquote><img src=""figures/IfcLoop-Math1.gif"" height=""31"" width=""180"">
		</blockquote> 
	 <p>where <i>V</i> and <i>E<sub>l</sub></i> are the number of unique
		vertices and oriented edges in the loop and <i>G<sup>l</sup></i> is the genus
		of the loop. </p> 
	 <blockquote class=""note"">NOTE&nbsp; Corresponding ISO 10303 entity: loop, the following subtypes have been incorporated into IFC: poly_loop as <I>IfcPolyLoop</I>, vertex_loop as <I>IfcVertexLoop</I>, edge_loop as <I>IfcEdgeLoop</I>. Please refer to ISO/IS 10303-42:1994, p. 136 for the final definition of the formal standard.</blockquote> 
	 <blockquote class=""history""> 
		HISTORY&nbsp; New Entity in IFC2x.</blockquote> 
	 <p>Informal propositions:</p> 
	 <ol> 
		<li>A loop has a finite extent.</li> 
		<li>A loop describes a closed (topological) curve with coincident start
		  and end vertices.</li> 
	 </ol>
</EPM-HTML>"
2457;IfcPolyLoop;"<EPM-HTML> 
<p><u>Definition from ISO/CD 10303-42:1992</u>: A
poly loop is a loop with straight edges bounding a planar region in
space. A poly loop is a loop of genus 1 where the loop is represented
by an ordered coplanar collection of points forming the vertices of the
loop. The loop is composed of straight line segments joining a point in
the collection to the succeeding point in the collection. The closing
segment is from the last to the first point in the collection.&nbsp;</p>
<p>The direction of the loop is in the direction of the line
segments. </p>

<blockquote class=""note"">
NOTE &nbsp;This entity exists primarily to facilitate the efficient communication of faceted B-rep models.
</blockquote>

<p>A poly loop shall conform to the following topological
constraints:</p>
<dl>
  <dd>- the loop has the genus of one.</dd>
  <dd>- the following equation shall be satisfied
    <dl>
      <dd> <img src=""figures/IfcPolyLoop-Math1.gif""
 height=""26"" width=""138""></dd>
    </dl>
  </dd>
</dl>
<p>The <i>IfcPolyLoop</i>
is always closed and the last segment is from the last <i>IfcCartesianPoint</i>
in the list of <i>Polygon</i>'s to the first <i>IfcCartesianPoint</i>.
Therefore the first point shall not be repeated at the end of the list,
neither by referencing the same instance, nor by using an additional
instance of&nbsp;<i>IfcCartesianPoint</i> having the
coordinates as the first point.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: poly_loop. Please refer to ISO/IS
10303-42:1994, p. 138 for the final definition of the formal standard.
Due to the general IFC model specification rule not to use multiple
inheritance, the subtype relationship to geometric_representation_item
is not included. The derived attribute <i>Dim</i> has been
added at this level.
</blockquote>

<blockquote class=""history"">
HISTORY &nbsp; New class in IFC Release 1.0
</blockquote>

<p>Informal propositions: </p>
<ol>
  <li>All the points in the polygon defining the poly loop shall be coplanar.</li>
  <li>The first and the last <i>Polygon</i> shall be different by value.</li>
</ol>

</EPM-HTML>"
2460;IfcVertexLoop;"<EPM-HTML>
	 <p><u>Definition from ISO/CD 10303-42:1992</u>: A vertex_loop is a loop of
		zero genus consisting of a single vertex. A vertex can exist independently of a
		vertex loop. The topological data shall satisfy the following constraint:</p>  
	 <blockquote>
		<img src=""figures/IfcVertexLoop-Math1.gif"" width=""132"" height=""18""
		 border=""0""></blockquote> 
	 <p>Informal propositions:</p> 
	 <ol> 
		<li>A vertex loop has zero extent and dimensionality.</li> 
		<li>The vertex loop has genus 0.</li> 
	 </ol> 
<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: vertex_loop. Please refer to ISO/IS 10303-42:1994, p. 121 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2x2.
</blockquote>

</EPM-HTML>"
2462;IfcEdgeLoop;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: An edge_loop is a loop with nonzero extent. It is a path in which the start and end vertices are the same. Its domain, if present, is a closed curve. An edge_loop may overlap itself.</p>
	 
<p>Informal propositions:</p> 
<ol> 
<li>The genus of the <i>IfcEdgeLoop</i> shall be 1 or greater.</li> 
<li>The Euler formula shall be satisfied:<br>(number of vertices) + genus - (number of edges) = 1;</li> 
<li>No edge may be referenced more than once by the same <i>IfcEdgeLoop</i> with the same sense. For this purpose, an edge which is not an oriented edge is considered to be referenced with the sense TRUE.</li> 
</ol> 
<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: edge_loop. Please refer to ISO/IS 10303-42:1994, p. 122 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history""> 
HISTORY&nbsp; New Entity in IFC2x2.
</blockquote>

</EPM-HTML>"
2467;IfcPath;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</U>: A path is a topological entity consisting of an ordered collection of oriented edges, such that the edge start vertex of each edge coincides with the edge end of its predecessor. The path is ordered from the edge start of the first oriented edge to the edge end of the last edge. The BOOLEAN value sense in the oriented edge indicates whether the edge direction agrees with the direction of the path (TRUE) or is the opposite direction (FALSE). </p> 

<p>An individual edge can only be referenced once by an individual path. An edge can be referenced by multiple paths. An edge can exist independently of a path. </p> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: path. Please refer to ISO/IS 10303-42:1994, p. 133 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2.0
</blockquote> 

<p><u>Informal proposition</u>:</p>
<ol>
<li>A path has dimensionality 1.</li>
<li>A path is arcwise connected.</li>
<li>The edges of the path do not intersect except at common vertices.</li>
<li>A path has a finite, non-zero extent.</li>
</ol> 

</EPM-HTML>"
2470;IfcOpenShell;"<EPM-HTML>
	 <p><u>Definition from ISO/CD 10303-42:1992</u>: An open shell is a shell of
		the dimensionality 2. Its domain, if present, is a finite, connected, oriented,
		2-manifold with boundary, but is not a closed surface. It can be thought of as
		a closed shell with one or more holes punched in it. The domain of an open
		shell satisfies 0
		&lt; &Xi; &lt; 1. An open shell is
		functionally more general than a face because its domain can have handles.</p> 
	 <p>The shell is defined by a collection of faces, which may be oriented
		faces. The sense of each face, after taking account of the orientation, shall
		agree with the shell normal as defined below. The orientation can be supplied
		directly as a BOOLEAN attribute of an oriented face, or be defaulted to TRUE if
		the shell member is a face without the orientation attribute.</p> 
	 <p>The following combinatorial restrictions on open shells and geometrical
		restrictions on their domains are designed, together with the informal
		propositions, to ensure that any domain associated with an open shell is an
		orientable manifold.</p> 
	 <ul> 
		<li>Each face reference shall be unique. </li> 
		<li>An open shell shall have at least one face. </li> 
		<li>A given face may exist in more than one open shell.</li> 
	 </ul> 
	 <p>The boundary of an open shell consists of the edges that are referenced
		only once by the face - bounds (loops) of its faces, together with all of their
		vertices. The domain of an open shell, if present, contains all edges and
		vertices of its faces.</p> 
	 <blockquote class=""note""> 
		NOTE&nbsp; Note that this is slightly different from the
		  definition of a face domain, which includes none of its bounds. For example, a
		  face domain may exclude an isolated point or line segment. An open shell domain
		  may not. (See the algorithm for computing below.)</blockquote> 
	 <p>In the current IFC Release only poly loops
		(<i>IfcPolyLoop</i>) are defined for bounds of face bound
		(<i>IfcFaceBound.Bound</i>). This will allow for faceted B-rep only. For
		further specification, including the Euler formulas to be satisfied, please
		refer to ISO 10303-42:1994.</p> 
	 <blockquote class=""note""> 
		NOTE&nbsp; Corresponding ISO 10303 entity:
		  open_shell, please refer to ISO/IS 10303-42:1994, p.148 for the final
		  definition of the formal standard.
         </blockquote>
         <blockquote class=""history"">
                HISTORY&nbsp; New class in IFC2x.
	 </blockquote> 
	 <p><u>Informal propositions</u>:</p> 
	 <ol> 
		<li>Every edge shall be referenced exactly twice by the face bounds of
		  the face. </li> 
		<li>Each oriented edge shall be unique. </li> 
		<li>No edge shall be referenced by more than two faces. </li> 
		<li>Distinct faces of the shell do not intersect, but may share edges or
		  vertices. </li> 
		<li>Distinct edges do not intersect but may share vertices. </li> 
		<li>Each face reference shall be unique. </li> 
		<li>The loops of the shell shall not be a mixture of poly loop and other
		  loop types. Note: this is given, since only poly loop is defined as face bound
		  definition. </li> 
		<li>The closed shell shall be an oriented arcwise connected 2-manifold.
		  </li> 
		<li>The Euler equation shall be satisfied. Note: Please refer to ISO/IS
		  10303-42:1994, p.148 for the equation.</li> 
	 </ol>
</EPM-HTML>"
2478;IfcTask;"<EPM-HTML> 
    <p>
      An <i>IfcTask</i> is an identifiable unit of work to be
      carried out in a construction project.
    </p>
    <p>
      A task is typically used to describe an activity for the
      construction or installation of products, but is not
      limited to these types. For example it might be used to
      describe design processes, move operations and other
      design, construction and operation related activities as
      well.
    </p>
    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC 1.0. Renamed from <i>IfcWorkTask</i> in IFC 2x.
    </blockquote>
    <blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Attributes <i>TaskTime</i> and <i>PredefinedType</i> added.  IfcMove and IfcOrderRequest has been removed in IFC2x4 and are now represented by <i>IfcTask</i>. Further information can be found in the description below.
    </blockquote>
    <p class=""use-head"">Type use definition</p>
    <p>
      <i>IfcTask</i> defines the anticipated or actual occurrence
      of any task; common information about task types is handled
      by <i>IfcTaskType</i>. The <i>IfcTaskType</i> (if present)
      may establish the common type name, usage (or predefined)
      type, common set of properties, and common product
      assignment using <i>IfcRelAssignsToProduct</i>. The
      <i>IfcTaskType</i> is attached using the
      <i>IfcRelDefinesByType.RelatingType</i> objectified
      relationship and is accessible by the inverse
      <i>IsTypedBy</i> attribute. Special type information
      relating to a task occurrence is asserted using
      <i>IfcTask.ObjectType</i> (inherited from
      <i>IfcObject</i>). Examples that may be used include fixed
      duration, fixed unit or fixed work. <i>IfcTask</i> can be
      aggregated to a task type in order to specify a task
      sequence or any time related information, e.g. the duration
      of a task. Please see the documentation of
      <i>IfcTaskType</i> for further information.
    </p>
    <p class=""use-head"">Attribute use definition</p>
    <p>
      Each occurrence of <i>IfcTask</i> is given a name that is
      indicative of its content (<i>IfcRoot.Name</i>). A textual
      description of the task may be provided and this may be
      further elaborated by a narrative long description
      (<i>IfcProcess.LongDescription</i>). A work method may be
      declared for the method of work used in carrying out a
      task. A task is identified as being either a milestone task
      or not. A milestone task is defined by the marker
      <i>IsMilestone</i>. and has no duration. A status and
      priority for each task may also be set.
    </p>
    <p class=""use-head"">Property set use definition</p>
    <p>
      The property sets relating to <i>IfcTask</i> are defined by
      <i>IfcPropertySet</i> and attached by the
      <i>IfcRelDefinesByProperties</i> relationship. They are
      accessible by the inverse <i>IsDefinedBy</i> relationship.
      Such property sets may define task parameters. No property
      sets for <i>IfcTask</i> are currently defined by IFC.
    </p>
    <p class=""use-head"">Connectivity Use Definition</p>
    <p>
      The relationship <i>IfcRelSequence</i> is used to indicate
      control flow. An <i>IfcTask</i> as a successor to an
      <i>IfcTask</i> indicates logical sequence how these tasks
      should be performed. <i>IfcTask</i>'s can be triggered or
      can trigger <i>IfcEvent</i>'s, which is also defined
      through the relationship <i>IfcRelSequence</i>.
    </p>
    <p class=""use-head"">Composition use definition</p>
    <p>
      <i>IfcTask</i> may be contained within an <i>IfcTask</i>
      using the <i>IfcRelNests</i> relationship. An
      <i>IfcTask</i> may in turn nest other <i>IfcTask</i>,
      <i>IfcProcedure</i> or <i>IfcEvent</i> entities. Such
      nesting indicates decomposed level of detail. From IFC2x4
      onwards it is required to have a summary task (root of all
      tasks), which is used to define a link to the work plan or
      work schedule. All subtasks of the summary tasks are then
      implicitly linked to this work plan or work schedule.
      Please note that the summary task is used for data
      organization and not meant to store typical task
      information as defined by the user. It is therefore
      recommended that the summary task is hidden from the user
      to avoid confusion. Please also note that
      <i>IfcRelNests</i> is used to show the dependency between
      regular tasks and recurring task definitions (please see
      the section about time and duration use definitions).
    </p>

    <p>
      As shown in Figure 13, the installation of a number of items of equipment within a
      particular space may be the subject of a single task which
      is identified as 'fix equipment in space 123'.
      <i>IfcTask</i> represents the occurrence of a work
      performance of a type of process in a construction plan.
    </p>
<table>
<tr><td><img src=""figures/ifctask_example.png"" alt=""task example"" border=""0"">
<tr><td><p class=""figure"">Figure 13 &mdash; Task visualization</td></tr>
</table>
    <p>
      A task may nest other tasks as sub-items; the nesting
      relationship is modeled by <i>IfcRelNests</i> as shown in Figure 14. For example,
      the construction of a stud wall may be designated as a
      nesting task named 'install wall #1' including other tasks
      such as 'install dry wall', 'install studs', 'wall taping',
      and 'erect wall' as sub-processes. A value that indicates
      the relative tree view position of the task (in comparison
      to the tree view position of other tasks and the task
      hierarchy defined by <i>IfcRelNests</i>).
    <p>The task order information that is used for viewing
      purposes is derived from the order defined by the
      <i>IfcRelNests</i> relationship and thus is independent of
      the logical task order defined through
      <i>IfcRelSequence</i>. The hierarchy and order defined
      through <i>IfcRelNests</i> enables to order the tasks in a
      tree view or list view structure.
    </p>
<table>
<tr><td><img src=""figures/ifctask_instantiation_diagram.png"" alt=""task instantiation diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 14 &mdash; Task nesting relationships</td></tr>
</table>

    </p>
    <p class=""use-head"">Time and duration use definition</p>
    <p>
      Compared to previous IFC releases, basic task time
      information (scheduled start time, scheduled finish
      time, duration) is now directly attached to <i>IfcTask</i>
      through the <i>TaskTime</i> attribute. Regular tasks are
      defined through <i>IfcTaskTime</i>. Recurring tasks are
      defined through <i>IfcTaskTimeRecurring</i>. In case a
      regular task is derived from a recurring task both tasks
      should be linked together through a <i>IfcRelNests</i>
      relationship, where <i>IfcRelNests.IsNestedBy</i> points to
      the recurring task and <i>IfcRelNests.Nests</i> points to
      all regular tasks that have been derived from the recurring
      task.
    </p>
    <p class=""use-head"">Assignment use definition</p>
    <p>
      Occurrences of <i>IfcTask</i> may be assigned to an
      <i>IfcWorkControl</i> (either a work plan or a work
      schedule) through <i>IfcRelAssignsToControl</i>. From
      IFC2x4 onwards it is suggested to use the 'summary task'
      (root element of the task hierarchy that is required for
      task management purposes) to assign all subtask to a work
      plan or work schedule. Resources used by tasks are assigned
      by <i>IfcRelAssignsToProcess</i>. Quantities of resources
      consumed by the task are dealt with by defining the
      <i>IfcElementQuantity</i> for the resource and not at the
      instance of <i>IfcTask</i>. Please note that the
      <i>IfcRelAssignsTasks</i> relationship class has been
      removed in IFC2x4 and is no longer available.
    </p>
    <p>
      An <i>IfcTask</i> may be assigned a Work Breakdown
      Structure (WBS) code. A WBS code is dealt with as a
      classification of task and is associated to a task
      occurrence using the <i>IfcRelAssociatesClassification</i>
      relationship class. As well as being to designate the code,
      the classification structure of the IFC model also enables
      the source of the work breakdown structure classification
      to be identified.
    </p>
    <p class=""use-head"">Constraint use definition</p>
    <p>
      Constraints may be applied to a task to indicate fixed task
      duration, fixed start or fixed finish (see Figure 15). The relationship
      <i>IfcRelAssociatesConstraint</i> is used where
      <i>RelatingConstraint</i> points to an <i>IfcMetric</i> and
      <i>RelatedObjects</i> includes the <i>IfcTask</i>.
      <i>IfcRelAssociatesConstraint.Name</i> identifies the
      attribute to be constrained using a period (""."") to
      dereference; for example, ""TaskTime.ScheduleStart"" refers
      to the <i>ScheduleStart</i> attribute on the
      <i>IfcTaskTime</i> entity referenced on the <i>TaskTime</i>
      attribute. The following attributes may be constrained:
    </p>
    <ul>
      <li>
        <b>'TaskTime.ScheduleDuration'</b>: Indicate fixed
        duration of task with ConstraintGrade=HARD and
        Benchmark=EQUALTO such that changes to an assigned
        <i>IfcConstructionResource.ResourceTime.ScheduleWork</i>
        should impact
        <i>IfcConstructionResource.ResourceTime.ScheduleUsage</i>,
        and vice-versa.
      </li>
      <li>
        <b>'TaskTime.ScheduleStart'</b>: Indicate constrained
        start date with ConstraintGrade=HARD and Benchmark of
        EQUALTO, GREATERTHANOREQUALTO, or LESSTHANOREQUALTO to
        indicate ""must start on"", ""start no earlier than"" or
        ""start no later than"" respectively where
        <i>IfcMetric.DataValue</i> indicates the specific
        <i>IfcDateTime</i>. Use SOFT constraint having LESSTHAN
        benchmark to indicate ""start as soon as possible"".
      </li>
      <li>
        <b>'TaskTime.ScheduleFinish'</b>: Indicate constrained
        finish date with ConstraintGrade=HARD and Benchmark of
        EQUALTO, GREATERTHANOREQUALTO, or LESSTHANOREQUALTO to
        indicate ""must finish on"", ""finish no earlier than"" or
        ""finish no later than"" respectively where
        <i>IfcMetric.DateValue</i> indicates the specific
        <i>IfcDateTime</i>. Use SOFT constraint having
        GREATERTHAN benchmark to indicate ""finish as late as
        possible"".
      </li>
    </ul>
    <p>
      A ""manual scheduled task"" is indicated with
      ConstraintGrade=HARD and Benchmark=EQUALTO for both
      <i>TaskTime.ScheduleStart</i> and
      <i>TaskTime.ScheduleFinish</i>.
    </p>

<table>
<tr><td><img src=""figures/ifctask_timeconstraint_example.png"" alt=""task time constraint example"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 15 &mdash; Task constraints</p></td></tr>
</table>

    <p>
      <b>Use Definition to represent other activities</b>
    </p>
    <p>
      The use definitions for <i>IfcTask</i> have been generalised to
      represent other activities as well, including actitities
      that had been defined by own entities in previous IFC
      releases. This includes
    </p>
    <ul>
      <li>Order actions</li>
      <li>Move operations</li>
    </ul>
    <p>
      <i>IfcTask</i> represents an order that might be carried
      out by a Helpdesk acting the role of interface for the
      organization between the facility user and the functional
      requirement of fulfilling their needs. The actual task
      represented by the <i>IfcTask</i> entity is turning a
      request into an order and initiating the action that will
      enable the order to be completed. The
      <i>IfcProjectOrder</i> or one of its subtypes including
      maintenance work order, is related to the <i>IfcTask</i>
      using <i>IfcRelAssignsToControl</i>.
    </p>
    <p>
      <i>IfcTask</i> can also be used to describe an activity
      that moves people, groups within an organization or
      complete organizations together with their associated
      furniture and equipment from one place to another. It thus
      replaces the previous IFC entity IfcMove. The functionality
      is represented in <i>IfcTask</i> as follows:<br>
    </p>
<ul>
      <li>Move from: The place from which actors and their
      associated equipment are moving.<br>
      Use <i>IfcRelAssignsToProcess</i> where
      <i>RelatingProcess</i> points to the task and
      <i>RelatedObjects</i> holds the location(s) from which to
      move.</li>
      <li>Move to: The place to which actors and their
      associated equipment are moving.<br>
      Use <i>IfcRelAssignsToProduct</i> where
      <i>RelatedObjects</i> points to the task(s) and
      <i>RelatingProduct</i> points to the location to which to
      move.</li>
     <li>Punch list: A list of points concerning a move that
      require attention.<br>
      Use <i>LongDescription</i> or else identify sub-tasks to
      track punch list items individually via <i>IfcRelNests</i>.</li>
</ul>

</EPM-HTML>"
2502;IfcProcedure;"<EPM-HTML> 
   <p>
      An <i>IfcProcedure</i> is a
      logical set of actions to be taken in response to an event
      or to cause an event to occur.
    </p>
    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC2x2
    </blockquote>
    <blockquote class=""change-ifc2x4"">
      IFC2x4 CHANGE&nbsp; <i>ProcedureType</i> renamed to <i>PredefinedType</i> and made optional (upward compatible).  Where rules WR1 and WR2 have been removed.
    </blockquote>
    <p class=""use-head"">Use definitions</p>
    <p>
      <i>IfcProcedure</i> is used to capture information about
      stepped processes such as calibration, start/stop
      procedures for equipment items, designated actions to take
      in the event of an emergency etc. A procedure is not a
      task, but may describe a set of tasks and their order of
      occurrence in response to or to cause an event.
    </p>
    <p class=""use-head"">Type use definition</p>
    <p>
      <i>IfcProcedure</i> defines the anticipated or actual
      occurrence of any procedure; common information about
      procedure types is handled by <i>IfcProcedureType</i>. The
      <i>IfcProcedureType</i> (if present) may establish the
      common type name, usage (or predefined) type, common nested
      procedures (using <i>IfcRelNests</i>), common set of
      properties, and common product assignment using
      <i>IfcRelAssignsToProduct</i>. The <i>IfcProcedureType</i>
      is attached using the
      <i>IfcRelDefinesByType.RelatingType</i> objectified
      relationship and is accessible by the inverse
      <i>IsTypedBy</i> attribute.
    </p>
    <p class=""use-head"">Property set use definition</p>
    <p>
      The property sets relating to <i>IfcProcedure</i> are
      defined by <i>IfcPropertySet</i> and attached by the
      <i>IfcRelDefinesByProperties</i> relationship. They are
      accessible by the inverse <i>IsDefinedBy</i> relationship.
      Such property sets may define procedure parameters. No
      property sets for <i>IfcProcedure</i> are currently defined
      by IFC.
    </p>
    <p class=""use-head"">Connectivity use definition</p>
    <p>
      The relationship <i>IfcRelSequence</i> is used to indicate
      control flow. An <i>IfcProcedure</i> as a successor to an
      <i>IfcEvent</i> indicates that the procedure should be
      performed in response to the event. An <i>IfcProcedure</i>
      as a predecessor to an <i>IfcEvent</i> indicates that the
      event should be trigerred following the procedure. As
      procedures have arbitrary duration, the
      <i>IfcRelSequence.SequenceType</i> attribute has no effect
      on an <i>IfcProcedure</i> but still applies to the opposite
      end of the relationship if <i>IfcTask</i> is used.
    </p>
    <p class=""use-head"">Composition use definition</p>
    <p>
      <i>IfcProcedure</i> may be contained within an
      <i>IfcTask</i> or <i>IfcProcedure</i> using the
      <i>IfcRelNests</i> relationship. An <i>IfcProcedure</i> may
      in turn nest other <i>IfcProcedure</i> or <i>IfcEvent</i>
      entities. Such nesting indicates decomposed level of
      detail.
    </p>
    <p>
      Note that a particular type of <i>IfcProcedure</i> is a
      caution, warning or other form of advisory note. Typically,
      it is anticipated that such a procedure would be assigned
      to the specific <i>IfcProcess</i> for which it gives advice
      using <i>IfcRelAssignsToProcess</i>.
    </p>
    <p class=""use-head"">Assignment use definition</p>
    <p>
      An <i>IfcProcedure</i> may be assigned to an
      <i>IfcWorkCalendar</i> to indicate times when such
      procedure may be performed using
      <i>IfcRelAssignsToControl</i>; otherwise the effective
      calendar is determined by the nearest <i>IfcProcess</i>
      ancestor with a calendar assigned. Advisory notes should be
      assigned to the specific <i>IfcProcess</i> for which it
      gives advice using <i>IfcRelAssignsToProcess</i>.
    </p>
    <p>
      For building operation scenarios, <i>IfcProcedure</i> may
      be assigned to a product (<i>IfcElement</i> subtype) using
      <i>IfcRelAssignsToProduct</i> to indicate a specific
      product occurrence that performs the procedure. For
      example, an <i>IfcActuator</i> may have a ""Close""
      procedure. If the <i>IfcProcedure</i> is defined by an
      <i>IfcProcedureType</i> and the <i>IfcProcedureType</i> is
      assigned to a product type (using
      <i>IfcRelAssignsToProduct</i>), then the
      <i>IfcProcedure</i> must be assigned to one or more
      occurrences of the specified product type using
      <i>IfcRelAssignsToProduct</i>.
    </p>
     
    <p>As shown in Figure 12, <i>IfcProcedure</i> does not restrict anything but
    describes specific steps of how something should happen.
    While a procedure does control/restrict in the sense of
    indicating ""this is how the task should be performed"" by
    nature of describing inner detail, this is not different than
    parts of a product indicating ""this is how the parts should
    be assembled"". Consequently, it doesn't restrict the outer
    item as a whole but provides inner detail of the item.</p>
<table>
<tr><td><img src=""figures/ifcprocedure_example.png"" alt=""procedure example"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 12 &mdash; Procedure relationships</p></td></tr>
</table>
    </p>
</EPM-HTML>"
2516;IfcEvent;"<EPM-HTML> 
   <p>
      An <i>IfcEvent</i> is something
      that happens that triggers an action or response.
    </p>
    <blockquote class=""history"">
      HISTORY&nbsp; New entity in IFC2x4
    </blockquote>
    <p class=""use-head"">Use definitions</p>
    <p>
      <i>IfcEvent</i> is used to capture information about
      particular things that happen or that may happen.
      Particularly used in work plans (or process maps) they
      identify e.g. a point at which a message containing
      information may be issued or at which a rule or constraint
      is invoked.
    </p>
    <p class=""use-head"">Type use definition</p>
    <p>
      <i>IfcEvent</i> defines the anticipated or actual occurrence of
      any event; common information about event types is handled
      by <i>IfcEventType</i>. The <i>IfcEventType</i> (if present) may
      establish the common type name, usage (or predefined) type,
      common set of properties, and common product assignment
      using <i>IfcRelAssignsToProduct</i>. The <i>IfcEventType</i> is attached
      using the <i>IfcRelDefinesByType.RelatingType</i> objectified
      relationship and is accessible by the inverse <i>IsTypedBy</i>
      attribute.
    </p>
    <p class=""use-head"">Property set use definition</p>
    <p>
      The property sets relating to <i>IfcEvent</i> are defined by
      <i>IfcPropertySet</i> and attached by the
      <i>IfcRelDefinesByProperties</i> relationship. They are accessible
      by the inverse <i>IsDefinedBy</i> relationship. Such property sets
      may define event parameters. No property sets for <i>IfcEvent</i>
      are currently defined by IFC.
    </p>
    <p class=""use-head"">Connectivity use definition</p>
    <p>
      The relationship <i>IfcRelSequence</i> is used to indicate control
      flow. An <i>IfcEvent</i> as a predecessor
      (<i>IfcRelSequence.RelatingProcess</i>) indicates that the
      succeeding process (typically <i>IfcProcedure</i> or <i>IfcTask</i>) is
      triggered in response to the event. An <i>IfcEvent</i> as a
      successor (<i>IfcRelSequence.RelatedProcess</i>) indicates that
      the completion of the preceeding process causes the event
      to be triggered. As events have zero duration, the
      <i>IfcRelSequence.SequenceType</i> attribute has no effect on an
      <i>IfcEvent</i> but still applies to the opposite end of the
      relationship if <i>IfcTask</i> is used.
    </p>
    <p class=""use-head"">Composition use definition</p>
    <p>
      <i>IfcEvent</i> may be contained within an <i>IfcTask</i> using the
      <i>IfcRelNests</i> relationship. The event is considered active
      during the time period of the enclosing task (including any
      assigned <i>IfcWorkCalendar</i>); that is such event may be
      triggered within the task time period but not outside of
      it. As an <i>IfcEvent</i> is considered to be atomic, no use is
      anticipated for nesting processes inside the event.
    </p>
    <p class=""use-head"">Assignment use definition</p>
    <p>
      An <i>IfcEvent</i> may be assigned to an <i>IfcWorkCalendar</i> to
      indicate times when such event is active using
      <i>IfcRelAssignsToControl</i>; otherwise the effective calendar is
      determined by the nearest <i>IfcProcess</i> ancestor with a
      calendar assigned.
    </p>
    <p>
      For building operation scenarios, <i>IfcEvent</i> may be assigned
      to a product (<i>IfcElement</i> subtype) using
      <i>IfcRelAssignsToProduct</i> to indicate a specific product
      occurrence that sources the event. For example, an
      <i>IfcSensor</i> for a motion sensor may have a ""Motion Sensed""
      event. If the <i>IfcEvent</i> is defined by an <i>IfcEventType</i> and
      the <i>IfcEventType</i> is assigned to a product type (using
      <i>IfcRelAssignsToProduct</i>), then the <i>IfcEvent</i> must be assigned
      to one or more occurrences of the specified product type
      using <i>IfcRelAssignsToProduct</i>.
    </p>		
</EPM-HTML>"
2536;IfcWorkControl;"<EPM-HTML> 
    <p>
      An <i>IfcWorkControl</i> is an abstract supertype which captures information that is common to both <i>IfcWorkPlan</i> and <i>IfcWorkSchedule</i>.
    </p>
    <blockquote class=""history"">
      HISTORY&nbsp; New class in IFC 2x
    </blockquote>
    <blockquote class=""change-ifc2x4"">
      CHANGE IFC2x4&nbsp; Corrected assignment of resources to work control in documentation. Assignment of tasks to work control updated based on changes of task time definitions and the introduction of a summary task. Identifier has been renamed (now Identification) and promoted to supertype <i>IfcControl</i>
    </blockquote>
    <p>
      A work control may have resources assigned to it, this is
      handled by the <i>IfcRelAssignsToControl</i> relationship.
      A work control should also define a context that gives
      further information about its usage. If no special context
      information is required then the <i>IfcProject</i> instance
      as a global context should be used instead. An explicit
      link between the work control and the <i>IfcProject</i> via
      <i>IfcRelDeclares</i> should then be provided.
    </p>
    <p>
      From IFC2x4 onwards the assignment of tasks to the work
      control is handled by the <i>IfcRelAssignsToControl</i>
      relationship. <i>IfcRelAssignsTasks</i> as used in previous
      IFC releases has been deleted and can not be used any
      longer. Another change in IFC2x4 is that it is not
      necessary to assign each task to a work control as it is
      regarded to be sufficient if the summary task (root task in
      the task hierarchy defined through <i>IfcRelNests</i>
      relationships) is assigned to a work control.
    </p>
    <p>
      The attribute <i>IfcWorkControl.Purpose</i> is used to
      define the purpose of either a work schedule or a work
      plan. In the case of <i>IfcWorkPlan</i>, the purpose
      attribute can be used to determine if the work plan is for
      cost estimating, task scheduling or some other defined
      purpose.
    </p>
    <p class=""use-head"">Property set use definition</p>
    <p>
      The property sets relating to the <i>IfcWorkControl</i> are
      defined by <i>IfcPropertySet</i> and attached by the
      <i>IfcRelDefinesByProperties</i> relationship. It is
      accessible by the inverse <i>IsDefinedBy</i> relationship.
      The following property set definition specific to the
      <i>IfcWorkControl</i> and its subtype are part of this IFC
      release:
    </p>
    <ul>
      <li>
        <a href=
        ""../../psd/IfcProcessExtension/Pset_WorkControlCommon.xml""
        target=""SOURCE"">Pset_WorkControlCommon</a>: common
        property set for work control
      </li>
    </ul>
</EPM-HTML>"
2546;IfcWorkPlan;"<EPM-HTML> 
    <p>
      An <i>IfcWorkPlan</i> represents work plans in a construction or a facilities management project.
    </p>
    <blockquote class=""history"">
      HISTORY: New Entity in IFC 2.0
    </blockquote>
    <p>
      A work plan contains a set of work schedules for different
      purposes (including construction and facilities
      management). Contained work schedules are defined through
      the <i>IfcRelAggregates</i> relationship. Through
      inheritance from <i>IfcWorkControl</i> it is also possible
      to define references to activities (for example, <i>IfcTask</i>)
      and resources used in the work plan.
    </p>
    <p>
      A work plan has information such as start date, finish
      date, total free float, and so on. <i>IfcWorkPlan</i> can
      also refer to the construction project represented by the
      single <i>IfcProject</i> instance (please also check the
      definition of <i>IfcWorkControl</i>).
    </p>
    <p>
      Figure 18 shows the backbone structure of a work plan that
      defines (1) contained work schedules through
      <i>IfcRelAggregates</i> and (2), if not assigned otherwise
      to contained work schedules, assigned tasks and resources
      through <i>IfcRelAssignsToControl</i>.
    </p>
<table>
<tr><td><img src=""figures/ifcworkplan_instantiation_diagram.png"" alt=
      ""work plan instantiation diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 18 &mdash; Work plan relationships</p><td></tr>
</table>

</EPM-HTML>"
2555;IfcWorkSchedule;"<EPM-HTML> 
    <p>
      An <i>IfcWorkSchedule</i>
      represents a task schedule of a work plan, which in turn
      can contain a set of schedules for different purposes.
    </p>
    <blockquote>
      <font color=""#0000FF"" size=""-1"">HISTORY: New Entity in IFC
      Release 2.0</font>
    </blockquote>

    <p class=""use-head>Assignment Use Definition</p>
    <p>
      An <i>IfcWorkSchedule</i> controls a set of tasks and
      resources defined through <i>IfcRelAssignsToControl</i>.
      Additionally, through the <i>IfcWorkControl</i> abstract
      supertype, the actors creating the schedule can be
      specified and schedule time information such as start time,
      finish time, and total float of the schedule can also be
      specified.
    </p>
    <p class=""use-head>Declaration Use Definition</p>
    <p>
      <i>IfcWorkSchedule</i> can reference a project (the
      single <i>IfcProject</i> instance) via
      <i>IfcRelDeclares</i>. The documents of the
      <i>IfcWorkSchedule</i> can be referenced by the
      <i>IfcRelAssociatesDocuments</i> relationship. </p>

    <p class=""use-head>Composition Use Definition</p>
    <p>A work schedule can include other work schedules as sub-items
      through <i>IfcRelNests</i> relationship. If not included in
      another work schedule it might be a part of a work plan
      (<i>IfcWorkPlan</i>) defined through
      <i>IfcRelAggregates</i> relationship.
    </p>

    <p>
      Figure 19 shows the backbone structure of a work schedule
      that defines (1) a context through <i>IfcRelDeclares</i>
      (not necessarily the project) and (2) controls tasks
      (typically the schedule summary task) and resources. Please
      note that a work calendar shall be assigned to the summary
      task and not the work schedule.
    </p>

<table>
<tr><td><img src=""figures/ifcworkschedule_instantiation_diagram.png"" alt=
      ""work schedule instantiation diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 19 &mdash; Work schedule relationships</p></td></tr>
</table>

</EPM-HTML>"
2564;IfcWorkCalendar;"<EPM-HTML>

<p>An <i>IfcWorkCalendar</i> defines working and non-working time periods for tasks and resources. It enables to define both specific time periods, such as from 7:00 till 12:00 on 25th August 2009, as well as repetitive time periods based on frequently used recurrence patterns, such as each Monday from 7:00 till 12:00 between 1st March 2009 and 31st December 2009.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

<p>A work calendar is a subtype of <i>IfcControl</i> and thus inherits the feature for controlling other objects through <i>IfcRelAssignsToControl</i>, which is used to define a work calendar for tasks (<i>IfcTask</i>) and resources (<i>IfcResource</i>). It also inherits a name and description attribute, whereas a name shall be given and a description may be given as an indication of its content and usage.</p>

<p>The definition of time periods can be derived from a base calendar and/or modified/defined by a set of working times and non-working exception times. All time periods defined by <i>IfcWorkCalendar.ExceptionTimes</i> override the time periods inherited from the base calendar (base calendar is defined as the next applicable calendar for the task or resource). Thus, exception times replace the working times from the base calendar.</p>

<p>The base calendar of a work calendar is defined by <i>IfcRelAssignsToControl</i>, where <i>IfcRelAssignsToControl.RelatingControl</i> is linked with the base calendar and <i>IfcRelAssignsToControl.RelatedObjects</i> is linked with work calendars that are derived from the base calendar. Although not restricted by the <i>IfcRelAssignsToControl</i> relationship it is only allowed to have one base calendar.</p>

<p>Figure 17 shows the definition of a work calendar, which is defined by a set of work times and exception times. The work times are defined as recurring patterns with optional boundaries (applying from and/or to a specific date). The shown example defines a simple work calendar with working times Monday to Thursday 8:00 to 12:00 and 13:00 to 17:00, Friday 8:00 to 14:00 and as exception every 1st Monday in a month the work starts one hour later - i.e. the working time on every 1st Monday in a month is overriden to be 9:00 to 12:00 and 13:00 to 17:00. Both the working time and the exception time is valid for the period of 01.09.2010 till 30.08.2011.</p>

<table summary=""instantiation diagram"">
<tr><td><img src=""figures/ifcworkcalendar_instantiation_diagram.png""
alt=""task type instantiation diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 17 &mdash; Work calendar instantiation</p></td></tr>
</table>

</EPM-HTML>
"
2575;IfcRelSequence;"<EPM-HTML>
    <p>
      <i>IfcRelSequence</i> is a
      sequential relationship between processes where one process
      must occur before the other in time and where the timing of
      the relationship may be described as a type of sequence.
      The relating process
      (<i>IfcRelSequence.RelatingProcess</i>) is considered to be
      the predecessor in the relationship (has precedence) whilst
      the related process (<i>IfcRelSequence.RelatedProcess</i>)
      is the successor.
    </p>
    <p>
      <i>IfcRelSequence</i> is defined as one-to-one
      relationship; therefore it assigns one predecessor to one
      successor.
    </p>
    <blockquote class=""history"">
        HISTORY&nbsp; New entity in IFC 1.0.
    </blockquote>
    <blockquote class=""change-ifc2x4"">
        IFC2x4 CHANGE&nbsp; Relocated to <i>IfcProcessExtension</i> schema.
        <i>TimeLag</i> and <i>SequenceType</i> made optional.
        USERDEFINED added to the <i>IfcSequenceType</i>
        enumeration. <i>UserDefinedSequenceType</i> attribute
        added. WHERE rule controlling use of the USERDEFINED
        enumeration added.
    </blockquote>
    <p class=""use-head"">Use definitions</p>
    <p>
      <em>IfcRelSequence</em> is used to describe the logical
      sequence relationship that exists between two processes.
      This logical relationship identifies that there is a
      predecessor or relating process and a successor or related
      process. In IFC, there may be one predecessor and one
      successor in the relationship. Many occurrences of
      <em>IfcRelSequence</em> may exist to describe the sequence
      relationships of a predecessor task with many successor
      tasks or of many predecessor tasks with one successor task,
      thus enabling a m:n sequence relationship between tasks.
      Please note that sequence relationships always should stay
      within the limits of a directed, non-cyclic graph.
    </p>
    <p>
      A sequence type may be set for a sequence. For tasks
      assigned to a work schedule, it is expected that the
      sequence type will be asserted. For a process map, where
      the sequence relationship between processes is simply a
      logical flow, it need not be asserted.
    </p>
    <p>
      A time lag may be assigned to a sequence, and the sequence
      type defines the way in which the time lag applies to the
      sequence either as a ratio or percentage of time duration
      (e.g. start successor task when predecessor is 50%
      complete) or as a time measure (e.g. start successor task 1
      week after commencement of the predecessor task). Care
      should be used when assigning a time lag to a sequence
      depending on the setting of the sequence type since there
      is no checking that the time lag value is in keeping with
      the sequence type set.
    </p>
</EPM-HTML>"
2590;IfcTaskType;"<EPM-HTML> 
    <p>
      An <i>IfcTaskType</i> defines a
      particular type of task that may be specified for use
      within a work control.
    </p>
    <blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4
    </blockquote>
    <p>
      An <i>IfcTaskType</i> provides for all forms of types of
      task that may be specified.
    </p>
    <p>
      Usage of <i>IfcTaskType</i> defines the parameters for one
      or more occurrences of <i>IfcTask</i>. Parameters may be
      specified through property sets that may be enumerated in
      the <i>IfcTaskTypeEnum</i> data type or through explict
      attributes of <em>IfcTaskType</em>. Task occurrences
      (<i>IfcTask</i> entities) are linked to the task type
      through the <i>IfcRelDefinesByType</i> relationship.
    </p>
    <p class=""use-head"">Composition use definition</p>
    <p>
      <i>IfcTaskType</i> may nest other <i>IfcTaskType</i> or
      <i>IfcTask</i> entities using the <i>IfcRelNests</i>
      relationship. Such nesting indicates decomposed level of
      detail. Nesting of <i>IfcTask</i> entities is used if a
      task type shall be detailed by a sequence of tasks or if
      there is a need to include additional time information such
      as the duration of subtasks. Please note that
      <i>IfcTask</i> entities being contained within an
      <i>IfcTaskType</i> are linked with their task occurrences
      via <i>IfcRelDefinesByObject</i> relationships. It is also
      possible to define a task type for these <i>IfcTask</i>
      entities via <i>IfcRelDefinesByType</i> relationships. For
      further information please see the documentation of
      <i>IfcRelDefinesByObject</i>.
    </p>
    <p>Figure 16 shows the definition of a task type that is part
      of a task template library. Please note that in this
      example the task type is further subdivided into tasks that
      define task times (for example, duration) and/or a task sequence.
    </p>
<table><tr><td><img src=""figures/ifctasktype_instantiation_diagram.png""
      alt=""task type instantiation diagram"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 16 &mdash; Task type relationships</p></td></tr>
</table>

</EPM-HTML>"
2594;IfcProcedureType;"<EPM-HTML> 
    <p>An <i>IfcProcedureType</i> defines a particular type of procedure that may be specified.</p>
    <blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4
    </blockquote>
    <p>An <i>IfcProcedureType</i> provides for all forms of types of procedure that may be specified.</p>
    <p>
      Usage of <i>IfcProcedureType</i> defines the parameters for
      one or more occurrences of <i>IfcProcedure</i>. Parameters
      may be specified through property sets that may be
      enumerated in the <i>IfcProcedureTypeEnum</i> data type or
      through explict attributes of <em>IfcProcedure</em>. Procedure occurrences
      (<i>IfcProcedure</i> entities) are linked to the procedure type
      through the <i>IfcRelDefinesByType</i> relationship.
    </p>
</EPM-HTML>"
2597;IfcEventType;"<EPM-HTML> 
    <p>An <i>IfcEventType</i> defines a particular type of event that may be specified.</p>
    <blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4
    </blockquote>
    <p>An <i>IfcEventType</i> provides for all forms of types of event that may be specified.</p>
    <p>Usage of <i>IfcEventType</i> defines the parameters for one or more occurrences of <i>IfcEvent</i>. Parameters may be specified through property sets that may be enumerated in the <i>IfcEventTypeEnum</i> data type or through explicit attributes of <em>IfcEvent</em>. Event occurrences (<i>IfcEvent</i> entities) are linked to the event type through the <i>IfcRelDefinesByType</i> relationship.</p>
</EPM-HTML>"
2604;IfcCostSchedule;"<EPM-HTML> 

<p>An <i>IfcCostSchedule</i> brings together instances of <i>IfcCostItem</i> either for the purpose of identifying purely cost information as in an estimate for constructions costs or for including cost information within another presentation form such as a work order.</p>

<blockquote>
<small><font color=""#0000FF"">HISTORY New Entity in IFC Release 2.0. Modified in IFC 2x2</font></small><br>
<small><font color=""#FF0000"">IFC2x4 CHANGE Attribute 'ID' changed to Identification and promoted to supertype IfcControl, <i>PredefinedType</i> made optional, attributes PreparedBy, SubmittedBy, TargetUsers removed.</font></small>
</blockquote>

<p><b><u>Declaration Use Definition</u></b></p> 
<p>The <b>IfcCostSchedule</b> may be declared within the project using the <a href=""../../ifckernel/lexical/ifcreldeclares.htm"">IfcRelDeclares</a> relationship where <i>RelatingContext</i> refers to the single <a href=""../../ifckernel/lexical/ifcproject.htm"">IfcProject</a> and <i>RelatedDefinitions</i> contains the <b>IfcCostSchedule</b>.  Alternatively, if the <b>IfcCostSchedule</b> is aggregated within another <a href=""../../ifckernel/lexical/ifccontrol.htm"">IfcControl</a> object, then it shall not have a direct declaration relationship (whereas the containing object may have a declaration relationship).</p> 
 
<p><b><u>Assignment Use Definition</u></b></p> 
<p> The <b>IfcCostSchedule</b> may be assigned to the following entities using relationships as indicated:</p> 
<ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a> (<a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a>): Persons and organizations involved in the preparation, submittal, and as target users.</li> 
</ul> 
<p> The <b>IfcCostSchedule</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a> relationship where <i>RelatingControl</i> refers to the <b>IfcCostSchedule</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifcsharedmgmtelements/lexical/ifccostitem.htm"">IfcCostItem</a>: Indicates costs published within this cost schedule, typically a single root cost item forming a hierarchy of nested cost items.</li> 
</ul> 
 
<p><b><u>Classification Use Definition</u></b></p> 
<p>Classifications may be applied using <a href=""../../ifckernel/lexical/ifcrelassociatesclassification.htm"">IfcRelAssociatesClassification</a> where <i>RelatedObjects</i> contains the  <b>IfcCostSchedule</b> and <i>RelatingClassification</i> refers to an <a href=""../../ifcexternalreferenceresource/lexical/ifcclassification.htm"">IfcClassification</a> or <a href=""../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm"">IfcClassificationReference</a>.</p> 
<ul> 
<li><a href=""../../ifcexternalreferenceresource/lexical/ifcclassification.htm"">IfcClassification</a>: Classifications to be used for cost items within the cost schedule.</li></li> 
</ul> 

<p><b><u>Approval Use Definition</u></b></p> 
<p>Approvals may be associated to indicate the status of acceptance or rejection using the <a href=""../../ifccontrolextension/lexical/ifcrelassociatesapproval.htm"">IfcRelAssociatesApproval</a> relationship where <i>RelatingApproval</i> refers to an <a href=""../../ifcapprovalresource/lexical/ifcapproval.htm"">IfcApproval</a> and <i>RelatedObjects</i> contains the <b>IfcCostSchedule</b>.  Approvals may be split into sub-approvals using <a href=""../../ifcapprovalresource/lexical/ifcapprovalrelationship.htm"">IfcApprovalRelationship</a> to track approval status separately for each party where <i>RelatingApproval</i> refers to the higher-level approval and <i>RelatedApprovals</i> contains one or more lower-level approvals.  The hierarchy of approvals implies sequencing such that a higher-level approval is not executed until all of its lower-level approvals have been accepted.</p> 
 

</EPM-HTML>"
2619;IfcProjectOrder;"<EPM-HTML> 
 
<p>A project order is a directive to purchase products and/or perform work, such as for construction or facilities management.</p> 
 
<p>Project orders are typically formal contracts between two organizations, where cost and time information may be rigid or flexible according to contained schedule types and constraints.</p> 
 
<blockquote class=""history"">HISTORY New entity in IFC 2.0</blockquote> 
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE Attribute 'ID' changed to Identification and promoted to supertype IfcControl.  Attribute 'LongDescription' added.</blockquote>
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Refer to the documentation at the supertype <a href=""../../ifckernel/lexical/ifccontrol.htm"">IfcControl</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_ProjectOrderChangeOrder.xml"" target=""SOURCE"">Pset_ProjectOrderChangeOrder</a> (<a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">CHANGEORDER</a>)</li> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_ProjectOrderMaintenanceWorkOrder.xml"" target=""SOURCE"">Pset_ProjectOrderMaintenanceWorkOrder</a> (<a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">MAINTENANCEWORKORDER</a>)</li> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_ProjectOrderMoveOrder.xml"" target=""SOURCE"">Pset_ProjectOrderMoveOrder</a> (<a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">MOVEORDER</a>)</li> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_ProjectOrderPurchaseOrder.xml"" target=""SOURCE"">Pset_ProjectOrderPurchaseOrder</a> (<a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">PURCHASEORDER</a>)</li> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_ProjectOrderWorkOrder.xml"" target=""SOURCE"">Pset_ProjectOrderWorkOrder</a> (<a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">WORKORDER</a>)</li> 
</ul> 
 
<p><b><u>Declaration Use Definition</u></b></p> 
<p>The <b>IfcProjectOrder</b> may be declared within the project using the <a href=""../../ifckernel/lexical/ifcreldeclares.htm"">IfcRelDeclares</a> relationship where <i>RelatingContext</i> refers to the single <a href=""../../ifckernel/lexical/ifcproject.htm"">IfcProject</a> and <i>RelatedDefinitions</i> contains the <b>IfcProjectOrder</b>.  Alternatively, if the <b>IfcProjectOrder</b> is aggregated within an <a href=""../../ifcprocessextension/lexical/ifcworkplan.htm"">IfcWorkPlan</a>, then it shall not have a direct declaration relationship (whereas the containing work plan may have a declaration relationship).</p> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>As shown in Figure 160, an <b>IfcProjectOrder</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcProjectOrder</b> and <i>RelatedObjects</i> contains one or more components.  Aggregation use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcsharedmgmtelements/lexical/ifccostschedule.htm"">IfcCostSchedule</a> components.  A cost schedule may indicate costs and quantities where the cost schedule type may designate whether rates and/or quantities are estimated or final.  Such cost schedule may have assigned cost items indicating detail, where each cost item may have assigned products, processes, or resources.</li> 
<li><a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">WORKORDER</a>: May contain <a href=""../../ifcprocessextension/lexical/ifcworkschedule.htm"">IfcWorkSchedule</a> components.  A work schedule may indicate tasks and scheduled times where the work schedule type may designate whether tasks and/or times are planned or actual.  Such work schedule may have assigned tasks indicating detail, where tasks may be assigned to products and may have assigned resources.</li> 
</ul> 
<p>The <b>IfcProjectOrder</b> may be nested into sub-items using <a href=""../../ifckernel/lexical/ifcrelnests.htm"">IfcRelNests</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcProjectOrder</b> and <i>RelatedObjects</i> contains one or more sub-items.  Nesting use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">WORKORDER</a>: May contain <b>IfcProjectOrder</b> sub-items having <i>PredefinedType</i> <a href=""../../ifcsharedmgmtelements/lexical/ifcprojectordertypeenum.htm"">CHANGEORDER</a>.  A work order may be nested into change orders to indicate contract ammendment, in order of issue.</li> 
</ul> 
<table>
<tr><td><img alt=""Composition Use Definition"" src=""figures/IfcProjectOrder-Composition.png""></td></tr>
<tr><td><p class=""figure"">Figure 161 &mdash; Project order composition</p></td></tr>
</table>
 
<p><b><u>Assignment Use Definition</u></b></p> 
<p>As shown in Figure 161, an <b>IfcProjectOrder</b> may be assigned to the following entities using relationships as indicated:</p> 
<ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a> (<a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a>): Organization issuing the order such as an owner or contractor.</li> 
</ul> 
<p> The <b>IfcProjectOrder</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a> relationship where <i>RelatingControl</i> refers to the <b>IfcProjectOrder</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a>: Organization(s) contracted to fulfill the order, typically a single contractor, subcontractor, or supplier.
</li> 
</ul> 
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcProjectOrder-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 162 &mdash; Project order assignment</p></td></tr>
</table>
 
<p><b><u>Approval Use Definition</u></b></p> 
<p>Approvals may be associated to indicate the status of acceptance or rejection using the <a href=""../../ifccontrolextension/lexical/ifcrelassociatesapproval.htm"">IfcRelAssociatesApproval</a> relationship where <i>RelatingApproval</i> refers to an <a href=""../../ifcapprovalresource/lexical/ifcapproval.htm"">IfcApproval</a> and <i>RelatedObjects</i> contains the <b>IfcProjectOrder</b>.  Approvals may be split into sub-approvals using <a href=""../../ifcapprovalresource/lexical/ifcapprovalrelationship.htm"">IfcApprovalRelationship</a> to track approval status separately for each party where <i>RelatingApproval</i> refers to the higher-level approval and <i>RelatedApprovals</i> contains one or more lower-level approvals.  The hierarchy of approvals implies sequencing such that a higher-level approval is not executed until all of its lower-level approvals have been accepted.</p>
 
</EPM-HTML>"
2631;IfcCostItem;"<EPM-HTML> 

<p>An <i>IfcCostItem</i> describes a cost or financial value together with descriptive information that describes its context in a form that enables it to be used within a cost schedule. An <i>IfcCostItem</i> can be used to represent the cost of goods and services, the execution of works by a process, lifecycle cost and more.</p>

<p>Each instance of <i>IfcCostItem</i> may have a name and a description. Depending on the use for which the cost is intended, these values should be asserted on the basis of agreement. For instance, the <i>Name</i> attribute could be used to provide a common value that enables distinct instances to be brought together in a nesting arrangement (see below) while the </i>Description</i> attribute may be used to provide text used for item description in a costing schedule.</p>

<p>An <i>IfcCostItem</i> can link one or many <i>IfcCostValue</i>'s representing a unit cost, total cost, or a unit cost with one or many quantities used to generate the total cost. The quantities can be given as individual quantities, or those quantities are provided as element quantities by one or many building elements.  The <i>IfcCostValue.CostType</i> attribute indicates the category of cost, which may be used to present the value in a particular column.  For nested cost items (having <i>IfcRelNests</i> relationship), <i>IfcCostValue.CostType</i> is significant such that <i>IfcCostValue.AppliedValue</i> is calculated as the sum of all nested costs having the same <i>IfcCostValue.CostType</i> or if set to an asterisk ('*'), then the sum of all nested costs of all cost types. An <i>IfcCostValue</i> may represent an original value or a value derived from formulas using <i>IfcAppliedValueRelationship</i>.  For example, taxes may be calculated as a percentage of a subtotal.</p>

<blockquote class=""history"">HISTORY New Entity in IFC Release 2.0.</blockquote>
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE Attribute <i>PredefinedType</i>, <i>CostValues</i>, and <i>CostQuantities</i> added.</blockquote>

<p><b><u>Classification Use Definition</u></b></p>

<p>Instances of <i>IfcCostItem</i> are used for cost estimates, budgets, and other forms, where a variety of identification codes are used extensively to identify the meaning of the cost. Examples include project phase codes, CSI codes, takeoff sequence numbers, and cost accounts. The model allows for all classes that are ultimately subtypes of <i>IfcObject</i> to inherit the ability to have one or more instances of <i>IfcClassificationReference</i> to be assigned. Where identification codes are required, the generic <i>IfcRelAssociatesClassification</i> facility should be used.</p>


<p><b><u>Composition Use Definition</u></b></p>

<p>An <i>IfcCostItem</i> can nest other instances of <i>IfcCostItem</i> through its relationships to <i>IfcRelNests</i>. This can be used to enable the development of complex groups of costs as may be found in cost schedules through to pages, sections and complete cost schedules.</p>

<p>There is always a summary cost item as the root item of the tree representing the cost item nesting. Subsequent instances of <i>IfcCostItem</i> are assigned to the summary cost item using <i>IfcRelNests</i>.  The summary cost item itself is assigned to <i>IfcCostSchedule</i> through the <i>IfcRelAssignsToControl</i> relationship.</p>

<p>Figure 157 illustrates a cost item composition used for a cost schedule.  Each line item has a quantity and separate unit costs where <i>IfcCostValue.CostType</i> indicates the category of cost.  The summary item has a hierarchy of costs calculated according to <i>IfcAppliedValueRelationship.ArithmeticOperator</i>, where <i>IfcCostValue.CostType</i> identifies the category to be totalled.  The Tax component has <i>IfcCostValue.CostType</i> set to 'Material' which indicates it is the sum of all nested values of the 'Material' category ($3 x 3000 + $118 x 100 = $20800).  The Subtotal component has <i>IfcCostValue.CostType</i> set to an asterisk ('*') which indicates it is the sum of all nested values of all categories.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""use definition"">
<tr><td valign=""bottom""><img src=""figures/IfcCostItem-Composition.png"" alt=""cost item"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 157 &mdash; Cost composition</p></td></tr>
</table>


<p><b><u>Assignment Use Definition</u></b></p>

<p>An <i>IfcCostItem</i> can be calculated based on quantities from objects through its relationship to <i>IfcRelAssignsToControl</i>.</p>

<p>For quantity-based costing, <i>IfcElement</i>, <i>IfcTask</i>, or <i>IfcResource</i> occurrence subtypes may be used.  Multiple elements may be assigned of the same or different types, using <i>IfcPhysicalQuantity</i> entities defined at each object.  Each <i>IfcPhysicalQuantity</i> type must be identical (for example, all values are <i>IfcAreaQuantity</i>) such that they can be added together.<p>

<p>For rate-based costing (specifically for <i>IfcCostScheduleTypeEnum.SCHEDULEOFRATES</i>), a single <i>IfcTypeProduct</i>, <i>IfcTypeProcess</i>, or <i>IfcTypeResource</i> subtype may be used to reflect rates for occurrences of such types.  This enables the possibility to generate a quantity-based cost schedule for occurrences based on types with rate-based cost schedules.</p>

<p><i>IfcRelAssignsToControl</i> is also used in the opposite direction to link the root <i>IfcCostItem</i> to an <i>IfcCostSchedule</i> where <i>RelatingControl</i> is the <i>IfcCostSchedule</i>. 

<p>Figure 158 illustrates cost item assignment derived from building elements.  The <i>IfcRelAssignsToControl</i> relationship indicates building elements for which quantities are derived.  Not shown, costs may also be derived from building elements by traversing assignment relationships from the assigned <i>IfcProduct</i> to <i>IfcProcess</i> to <i>IfcResource</i>, where all costs ultimately originate at resources.  It is also possible for cost items to have assignments from processes or resources directly.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""use definition"">
<tr><td valign=""bottom""><img src=""figures/IfcCostItem-Assignment.png"" alt=""cost item"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 168 &mdash; Cost assignment</p></td></tr>
</table>

</EPM-HTML>"
2638;IfcPermit;"<EPM-HTML> 
 
<p>A permit is a permission to perform work in places and on artifacts where regulatory, security or other access restrictions apply.</p> 
 
<blockquote class=""history"">HISTORY New entity in IFC2x2</blockquote> 
<blockquote class=""change-ifc2x4"">IFC2x4 CHANGE  PermitID renamed to Identification and promoted to supertype IfcControl, Attributes <i>PredefinedType</i>, <i>Status</i>, and <i>LongDescription</i> added.</blockquote>
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Refer to the documentation at the supertype <a href=""../../ifckernel/lexical/ifccontrol.htm"">IfcControl</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_Permit.xml"" target=""SOURCE"">Pset_Permit</a></li> 
</ul> 
 
<p><b><u>Declaration Use Definition</u></b></p> 
<p>The <b>IfcPermit</b> may be declared within the project using the <a href=""../../ifckernel/lexical/ifcreldeclares.htm"">IfcRelDeclares</a> relationship where <i>RelatingContext</i> refers to the single <a href=""../../ifckernel/lexical/ifcproject.htm"">IfcProject</a> and <i>RelatedDefinitions</i> contains the <b>IfcPermit</b>.  Alternatively, if the <b>IfcPermit</b> is aggregated within an <a href=""../../ifcprocessextension/lexical/ifcworkplan.htm"">IfcWorkPlan</a>, then it shall not have a direct declaration relationship (whereas the containing work plan may have a declaration relationship).</p> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcPermit</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcPermit</b> and <i>RelatedObjects</i> contains one or more components.  Aggregation use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifcsharedmgmtelements/lexical/ifcpermittypeenum.htm"">ACCESS</a>: May contain <a href=""../../ifcprocessextension/lexical/ifcworkcalendar.htm"">IfcWorkCalendar</a> components.  A work calendar may indicate the time period of the permit and allowed times when work may be performed.  Such work calendar may have assigned resources indicating equipment or labor permitted at various times.</li> 
<li><a href=""../../ifcsharedmgmtelements/lexical/ifcpermittypeenum.htm"">WORK</a>: May contain <a href=""../../ifcprocessextension/lexical/ifcworkschedule.htm"">IfcWorkSchedule</a> components.  A work schedule may indicate tasks and scheduled times where the work schedule type may designate whether tasks and/or times are planned or actual.  Such work schedule may have assigned tasks indicating detail, where tasks may be assigned to products and may have assigned resources.</li> 
</ul> 
<p>As shown in Figure 159, an <b>IfcPermit</b> may be nested into sub-items using <a href=""../../ifckernel/lexical/ifcrelnests.htm"">IfcRelNests</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcPermit</b> and <i>RelatedObjects</i> contains one or more sub-items.  Nesting use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <b>IfcPermit</b> sub-items.  A permit may be nested to indicate permit ammendments, in order of issue.</li> 
</ul> 
<table>
<tr><td><img alt=""Composition Use Definition"" src=""figures/IfcPermit-Composition.png""></td></tr>
<tr><td><p class=""figure"">Figure 159 &mdash; Permit composition</p></td></tr>
</table>
 
<p><b><u>Assignment Use Definition</u></b></p> 
<p>As shown in Figure 160, an <b>IfcPermit</b> may be assigned to the following entities using relationships as indicated:</p> 
<ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a> (<a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a>): Organization issuing the permit such as a local government agency or security organization.</li> 
</ul> 
<p> The <b>IfcPermit</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a> relationship where <i>RelatingControl</i> refers to the <b>IfcPermit</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a>: Organization(s) bound to the permit, typically a single contractor.
</li> 
</ul> 
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcPermit-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 160 &mdash; Permit assignment</p></td></tr>
</table>
 
<p><b><u>Approval Use Definition</u></b></p> 
<p>Approvals may be associated to indicate the status of acceptance or rejection using the <a href=""../../ifccontrolextension/lexical/ifcrelassociatesapproval.htm"">IfcRelAssociatesApproval</a> relationship where <i>RelatingApproval</i> refers to an <a href=""../../ifcapprovalresource/lexical/ifcapproval.htm"">IfcApproval</a> and <i>RelatedObjects</i> contains the <b>IfcPermit</b>.  Approvals may be split into sub-approvals using <a href=""../../ifcapprovalresource/lexical/ifcapprovalrelationship.htm"">IfcApprovalRelationship</a> to track approval status separately for each party where <i>RelatingApproval</i> refers to the higher-level approval and <i>RelatedApprovals</i> contains one or more lower-level approvals.  The hierarchy of approvals implies sequencing such that a higher-level approval is not executed until all of its lower-level approvals have been accepted.</p> 
 
 
</EPM-HTML>"
2648;IfcActionRequest;"<EPM-HTML> 
 
<p>A request is the act or instance of asking for something, such as a request for information, bid submission, or performance of work.</p> 
 
<p>Requests may take many forms depending on the need including fault reports for maintenance, requests for small works, and purchase requests (where these are to be made through a help desk or buying function).</p> 
 
<blockquote><small><font color=""#0000ff"">HISTORY: New entity in IFC2x2<br></font></small></blockquote> 
<blockquote><small><font color=""#FF0000"">IFC2x4 CHANGE  RequestID renamed to Identification and promoted to supertype IfcControl, attributes <i>PredefinedType</i>, <i>Status</i>, and <i>LongDescription</i> added.</font></small></blockquote>
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <a href=""../../ifckernel/lexical/ifcreldefinesbyproperties.htm"">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute.  Refer to the documentation at the supertype <a href=""../../ifckernel/lexical/ifccontrol.htm"">IfcControl</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcSharedMgmtElements/Pset_ActionRequest.xml"" target=""SOURCE"">Pset_ActionRequest</a></li> 
</ul> 
 
<p><b><u>Declaration Use Definition</u></b></p> 
<p>The <b>IfcActionRequest</b> may be declared within the project using the <a href=""../../ifckernel/lexical/ifcreldeclares.htm"">IfcRelDeclares</a> relationship where <i>RelatingContext</i> refers to the single <a href=""../../ifckernel/lexical/ifcproject.htm"">IfcProject</a> and <i>RelatedDefinitions</i> contains the <b>IfcActionRequest</b>.  Alternatively, if the <b>IfcActionRequest</b> is aggregated within an <a href=""../../ifcprocessextension/lexical/ifcworkplan.htm"">IfcWorkPlan</a>, then it shall not have a direct declaration relationship (whereas the containing work plan may have a declaration relationship).</p> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>As shown in Figure 155, an <b>IfcActionRequest</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcActionRequest</b> and <i>RelatedObjects</i> contains one or more components.  Aggregation use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcsharedmgmtelements/lexical/ifccostschedule.htm"">IfcCostSchedule</a> components.  A cost schedule may indicate costs and quantities where the cost schedule type may designate whether rates and/or quantities are estimated or final.  Such cost schedule may have assigned cost items indicating detail, where each cost item may have assigned products, processes, or resources.</li> 
</ul> 
<p>The <b>IfcActionRequest</b> may be nested into sub-items using <a href=""../../ifckernel/lexical/ifcrelnests.htm"">IfcRelNests</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcActionRequest</b> and <i>RelatedObjects</i> contains one or more sub-items.  Nesting use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <b>IfcActionRequest</b> sub-items.  A request may be nested into follow-up requests, in order of issue.</li> 
</ul> 
<table>
<tr><td><img alt=""Composition Use Definition"" src=""figures/IfcActionRequest-Composition.png""></td></tr>
<tr><td><p class=""figure"">Figure 155 &mdash; Action request composition</p></td></tr>
</table> 
 
<p><b><u>Assignment Use Definition</u></b></p> 
<p>As shown in Figure 156, an <b>IfcActionRequest</b> may be assigned to the following entities using relationships as indicated:</p> 
<ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a> (<a href=""../../ifckernel/lexical/ifcrelassignstoactor.htm"">IfcRelAssignsToActor</a>): Person or organization issuing the request such as a tenant or owner.</li> 
</ul> 
<p>The <b>IfcActionRequest</b> may have assignments of its own using the <a href=""../../ifckernel/lexical/ifcrelassignstocontrol.htm"">IfcRelAssignsToControl</a> relationship where <i>RelatingControl</i> refers to the <b>IfcActionRequest</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul> 
<li><a href=""../../ifckernel/lexical/ifcactor.htm"">IfcActor</a>: Person or organization(s) fulfilling the request such as a facilities manager or contractor.
</li> 
</ul> 
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcActionRequest-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 156 &mdash; Action request assignment</p></td></tr>
</table>
 
<p><b><u>Approval Use Definition</u></b></p> 
<p>Approvals may be associated to indicate the status of acceptance or rejection using the <a href=""../../ifccontrolextension/lexical/ifcrelassociatesapproval.htm"">IfcRelAssociatesApproval</a> relationship where <i>RelatingApproval</i> refers to an <a href=""../../ifcapprovalresource/lexical/ifcapproval.htm"">IfcApproval</a> and <i>RelatedObjects</i> contains the <b>IfcActionRequest</b>.  Approvals may be split into sub-approvals using <a href=""../../ifcapprovalresource/lexical/ifcapprovalrelationship.htm"">IfcApprovalRelationship</a> to track approval status separately for each party where <i>RelatingApproval</i> refers to the higher-level approval and <i>RelatedApprovals</i> contains one or more lower-level approvals.  The hierarchy of approvals implies sequencing such that a higher-level approval is not executed until all of its lower-level approvals have been accepted.</p> 
 
 
</EPM-HTML>"
2661;IfcConstructionResource;"<EPM-HTML>

<p><i>IfcConstructionResource</i> is an abstract generalization of the different resources used in
construction projects, mainly labor, material, equipment and product resources, plus subcontracted resources and aggregations such as a crew resource.</p>

<p>A resource represents ""use of something"" and does not necessarily correspond to a single item such as a person or vehicle, but
represents a pool of items having limited availability such as general labor or an equipment fleet. A resource can represent either a generic resource pool (not having any task assignment) or a task-specific resource allocation (having an <i>IfcTask</i>
assignment).</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Modified in to promote <i>ResourceIdentifer</i> and <em>ResourceGroup</em> (renamed to <em>LongDescription</em>) to supertype <i>IfcResource</i> and add attributes as described.
</blockquote>

<p class=""use-head"">Type use definition</p>
<p><i>IfcConstructionResource</i> defines the occurrence of any construction resource; common information about construction resource types is handled by <i>IfcConstructionResourceType</i>. The <i>IfcConstructionResourceType</i> (if present) may establish the common type name, common properties, common cost rates, and common productivities applied to specific task types. The <i>IfcConstructionResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute as shown in Figure 186.</p>
<p>The resource type may provide shared productivity and cost information, allowing tasks and resources to be selected according to lowest cost and/or shortest duration. Given an <i>IfcProduct</i> of a particular <i>IfcTypeProduct</i> type, an <i>IfcTypeProcess</i> may be selected from those assigned to the product type using <i>IfcRelAssignsToProduct</i>, and an <i>IfcTypeResource</i> may be selected from those assigned to the process type using <i>IfcRelAssignsToProcess</i>. Then <i>IfcTask</i> and <i>IfcConstructionResource</i> occurrences may be instantiated from the type definitions, applying productivitity and rate information to assigned quantities to calculate <i>ResourceTime.ScheduleWork</i>. Task durations can then be calculated by dividing <i>ResourceTime.ScheduleWork</i> by <i>ResourceTime.ScheduleUsage</i>.</p>
<table>
<tr><td><img alt=""Type Use Definition"" src=""figures/IfcConstructionResource-Type.png""></td></tr>
<tr><td><p class=""figure"">Figure 186 &mdash; Construction resource type use</p></td></tr>
</table>

<p class=""use-head"">Composition use definition</p>
<p>Resources may be decomposed into allocation pools using the <i>IfcRelNests</i> relationship as shown in Figure 187. For example, an <i>IfcLaborResource</i> for ""Electrician"" may be decomposed into three task-specific <i>IfcLaborResource</i> objects: ""Electrical Rough-in"", ""First Floor Circuits"", and ""Second Floor Circuits"". Both relating and related sides may represent the same <i>ResourceTime.ScheduleUsage</i> quantity (for example, 6 workers time-shared), or the related side may break out <i>ResourceTime.ScheduleUsage</i> quantities for reserved use (for example, 4 workers and 2 workers).</p> 
<p>A common scenario is two nesting levels where the first-level resources have no task assignments; while second-level resources have specific task assignments indicating that the resource is subdivided into allocations for specific tasks. While the model allows unlimited nesting of resources, implementer agreements may restrict to two nesting levels with task assignments specifically at the second level.</p>
<table>
<tr><td><img alt=""Composition Use Definition"" src=""figures/IfcConstructionResource-Composition.png""></td></tr>
<tr><td><p class=""figure"">Figure 187 &mdash; Construction resource composition use</p></td></tr>
</table>

<p class=""use-head"">Declaration use definition</p>
<p>A root-level resource (specifically <i>IfcCrewResource</i> or <i>IfcSubContractResource</i>) is declared within the project by <i>IfcRelDeclares</i> where <i>RelatingContext</i> refers to the single <i>IfcProject</i> and <i>RelatedObjects</i> refers to one or more <i>IfcConstructionResource</i>, and other root-level objects within the project.</p>

<p class=""use-head"">Assignment use definition</p>
<p>A resource may be assigned to an actor by <i>IfcRelAssignsToActor</i> where <i>RelatingActor</i> refers to an <i>IfcActor</i> and <i>RelatedObjects</i> refers to one or more <i>IfcConstructionResource</i> or other objects. Such relationship indicates the actor responsible for allocating the resource such as partitioning into task-specific allocations, delegating to other actors, and/or scheduling over time. Note that this assignment does not indicate the person or organization performing the work; that is indicated by <i>IfcRelAssignsToResource</i>. The actor responsible for the resource may or may not be the same as any actor(s) performing work.</p>
<p>A resource may be assigned to a control by <i>IfcRelAssignsToControl</i> where <i>RelatingProduct</i> refers to an <i>IfcControl</i> and <i>RelatedObjects</i> refers to one or more <i>IfcConstructionResource</i> or other objects. Most commonly an <i>IfcWorkCalendar</i> is assigned indicating availability of the resource, where such calendar is nested within a base calendar or an <i>IfcWorkPlan</i> which in turn is assigned to the <i>IfcProject</i>.</p>
<p>A resource may be assigned to a group by <i>IfcRelAssignsToGroup</i> where <i>RelatingGroup</i> refers to an <i>IfcGroup</i> and <i>RelatedObjects</i> refers to one or more <i>IfcConstructionResource</i> or other objects. Most commonly an <i>IfcAsset</i> is assigned indicating the asset to be tracked, where such asset is nested within an <i>IfcInventory</i> which in turn is assigned to the <i>IfcProject</i>.</p>
<p>A resource may be assigned to a product by <i>IfcRelAssignsToProduct</i> where <i>RelatingProduct</i> refers to an <i>IfcProduct</i> and <i>RelatedObjects</i> refers to one or more <i>IfcConstructionResource</i> or other objects. Most commonly an <i>IfcElement</i> subtype is assigned indicating the product to be constructed, where such product is connected to a spatial
structure which in turn is aggregated within the <i>IfcProject</i>.</p>
<p>A resource may be assigned to a process by <i>IfcRelAssignsToProcess</i> where <i>RelatingProcess</i> refers to an <i>IfcProcess</i> and <i>RelatedObjects</i> refers to one or more <i>IfcConstructionResource</i> or other objects. Most commonly an <i>IfcTask</i> is assigned indicating the task to be performed by the resource, where such task is nested within a summary task which in turn is assigned to the <i>IfcProject</i>.</p> 
<p>A resource may have assignments of other objects using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionResource</i> and <i>RelatedObjects</i> refers to one or more objects such as <i>IfcActor</i> or <i>IfcProduct</i> subtypes. This relationship indicates specific objects assigned to fulfill resource usage.</p>
<p>Figure 188 illustrates resource assignment.</p>
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcConstructionResource-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 188 &mdash; Construction resource assignment use</p></td></tr>
</table>

<p class=""use-head"">Constraint use definition</p>
<p>Constraints may be applied to a resource to indicate fixed work (such as total person-hours) or fixed usage (such as simultaneous workers). The relationship <i>IfcRelAssociatesConstraint</i> is used where <i>RelatingConstraint</i> points to an <i>IfcMetric</i> and <i>RelatedObjects</i> includes the <i>IfcConstructionResource</i> as shown in Figure 189. <i>IfcRelAssociatesConstraint.Name</i> identifies the attribute to be constrained using a period (""."") to dereference; for example, ""ResourceTime.ScheduleWork"" refers to the <i>ScheduleWork</i> attribute on the <i>IfcResourceTime</i> entity referenced on the <i>ResourceTime</i> attribute. The following attributes may be constrained:</p>
<ul>
<li><b>'ResourceTime.ScheduleUsage'</b>: Indicate fixed usage (e.g.
simultaneous workers) with <i>ConstraintGrade=HARD</i> and
<i>Benchmark=EQUALTO</i> such that changes to
<i>ResourceTime.ScheduleWork</i> should impact the assigned
<i>IfcTask.TaskTime.ScheduleDuration</i> and vice-versa</li>
<li><b>'ResourceTime.ScheduleWork'</b>: Indicate fixed work (e.g.
total person-hours) with <i>ConstraintGrade=HARD</i> and
<i>Benchmark=EQUALTO</i> such that changes to
<i>ResourceTime.ScheduleUsage</i> should impact the assigned
<i>IfcTask.TaskTime.ScheduleDuration</i> and vice-versa.</li>
</ul>
<table>
<tr><td><img alt=""Constraint Use Definition"" src=""figures/IfcConstructionResource-Constraint.png""></td></tr>
<tr><td><p class=""figure"">Figure 189 &mdash; Construction resource constraint use</p></td></tr>
</table>

<p class=""use-head"">Time series use definition</p>
<p>Time series may be applied to a resource to indicate the break-out of attribute values over time. The relationship <i>IfcRelAssociatesTimeSeries</i> is used where <i>RelatingTimeSeries</i> points to an <i>IfcTimeSeries</i> (either <i>IfcRegularTimeSeries</i> or <i>IfcIrregularTimeSeries</i>) and <i>RelatedObjects</i> includes the <i>IfcConstructionResource</i> as shown in Figure 190. <i>IfcRelAssociatesTimeSeries.Name</i> identifies the attribute to be constrained using a period (""."") to dereference; for example, ""ResourceTime.ScheduleWork"" refers to the <i>ScheduleWork</i> attribute on the <i>IfcResourceTime</i> entity referenced on the <i>ResourceTime</i> attribute. Refer to attribute descriptions on IfcResourceTime for attribute-specific usage.</p>
<p>Each <i>IfcTimeSeriesValue</i> indicates a LIST of values, where the sequence of the value corresponds to the <i>IfcCostValue</i> at <i>IfcConstructionResource.CostRatesConsumed</i>. For example, if <i>CostRatesConsumed</i> has two <i>IfcCostValue</i> items in the LIST, ""Standard"" and ""Overtime"", then <i>IfcTimeSeriesValue(IfcDuration('T8H0M0S'),IfcDuration('T2H0M0S'))</i> would indicate 8 hours at Standard rate and 2 hours at Overtime rate. If the list of values at <i>IfcTimeSeriesValue.ListValues</i> is less than the size of <i>CostRatesConsumed</i>, then subsequent values are considered to be zero.</p>
<table>
<tr><td><img alt=""Time Series Use Definition"" src=""figures/IfcConstructionResource-TimeSeries.png""></td></tr>
<tr><td><p class=""figure"">Figure 190 &mdash; Construction resource time series use</p></td></tr>
</table>

<p class=""use-head"">Document use definition</p>
<p>Documents may be published for work plans consisting of schedules, calendars, tasks, and resources. The relationship <i>IfcRelAssociatesDocument</i> may be used to preserve mappings to such document where <i>RelatingDocument</i> points to an <i>IfcDocumentReference</i> and <i>RelatedObjects</i> includes the <i>IfcConstructionResource</i> as shown in Figure 191.
<i>IfcDocumentReference.ItemReference</i> identifies the resource within the scope of the document, such as an integer or guid. The <i>IfcDocumentReference.ReferencedDocument</i> corresponds to the document which is uniquely identified by <i>IfcDocumentInformation.DocumentId</i> and/or <i>IfcDocumentInformation.PublicationLocation</i>. Such document mapping allows items in the document to be updated from the building information model and vice-versa.</p>
<table>
<tr><td><img alt=""Document Use Definition"" src=""figures/IfcConstructionResource-Document.png""></td></tr>
<tr><td><p class=""figure"">Figure 191 &mdash; Construction resource document use</p></td></tr>
</table>

<p class=""use-head"">Baseline use definition</p>
<p>A resource may have any number of baselines defined using the relationship <i>IfcRelDefinesByObject</i> where <i>RelatingObject</i> is the ""current"" resource and <i>RelatedObjects</i> consists of multiple ""baseline"" resources, each representing a copy of the resource as it existed at an earlier point in time as shown in Figure 192. Each baseline <i>IfcConstructionResource</i> is identified by its nested <i>IfcRelAssignsToControl</i> relationship to an <i>IfcWorkSchedule</i> having
<i>PredefinedType=BASELINE</i>, <i>IfcWorkSchedule.CreationDate</i> indicating the date of the baseline, and
<i>IfcWorkSchedule.Name</i> indicating the name of the baseline.</p>
<table>
<tr><td><img alt=""Baseline Use Definition"" src=""figures/IfcConstructionResource-Baseline.png""></td></tr>
<tr><td><p class=""figure"">Figure 192 &mdash; Construction resource baseline use</p></td></tr>
</table>

</EPM-HTML>"
2675;IfcConstructionEquipmentResource;"<EPM-HTML> 

<p><i>IfcConstructionEquipmentResource</i> is usage of construction equipment to assist in the performance of construction. Construction Equipment resources are wholly or partially consumed or occupied in the performance of construction.
</p> 
 
<blockquote>
HISTORY: New Entity in IFC Release 2.0.  Base type and documentation extended in IFC2x4.
</blockquote>

<p>Occurrences of <i>IfcConstructionEquipmentResource</i> are products that are used as resources to assist the process of construction. More specifically, they are products that are standalone items brought to a project to fulfil a particular purpose. Examples might be a tower crane or other mobile crane, a screwing machine, a lifting hoist etc. They are explicitly instances of <i>IfcProduct</i>  and may be drawn from various of the subtype, for instance <em>IfcTransportElement</em>, <i>IfcDiscreteAccessory</i>, <i>IfcProxy</i> (for particular cases where more precise usage details are not available).</p>

<p>A product that is used as an <i>IfcConstructionEquipmentResource</i> is referenced using the <i>IfcRelAssignsToResource.RelatedObjects</i> relationship.</p>

<p>Use definitions for composition, assignment, constraints, time series, and baselines are described at the base type <i>IfcConstructionResource</i>.</p>

<p class=""use-head"">Type use definition</p>
<p><i>IfcConstructionEquipmentResource</i> defines the occurrence of any construction equipment resource; common information about construction equipment resource types is handled by <i>IfcConstructionEquipmentResourceType</i>.  The <i>IfcConstructionEquipmentResourceType</i> (if present) may establish the common type name, common properties, and common productivities for various task types using <i>IfcRelAssignsToProcess</i>.  The <i>IfcConstructionEquipmentResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute.</p>
<p></p>

<p class=""use-head"">Quantity use definition</p>
<p>The quantities relating to the <i>IfcConstructionEquipmentResource</i> are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. It is accessible by the inverse <i>IsDefinedBy</i> relationship. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities can be defined being subjected to local standard of measurement with another string value assigned to <i>Name</i> and a value provided for <i>MethodOfMeasurement</i>.
<ul>
   <li><a href=""../../qto/IfcConstructionMgmtDomain/Qto_ConstructionEquipmentResourceBaseQuantities.xml"" target=""SOURCE"">
   Qto_ConstructionEquipmentResourceBaseQuantities</a>: base quantities for all construction equipment resources.
   </li>
</ul>

<p class=""use-head"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResource</i>, a construction equipment resource may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionEquipmentResource</i> and <i>RelatedObjects</i> contains one or more <i>IfcProduct</i> subtypes as shown in Figure 183.  Such relationship indicates the equipment used as input for the resource.  Such products are not contained within a building structure but are referenced within a construction spatial zone, specifically <i>IfcSpatialZone</i> with <i>PredefinedType=CONSTRUCTION</i>, which is aggregated within the <i>IfcProject</i>.  There may be multiple chains of production such that the assigned equipment may have their own task and resource assignments for assembling such equipment.</p>
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcConstructionEquipmentResource-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 183 &mdash; Construction equipment resource assignment</p></td></tr>
</table>

<p></p>

</EPM-HTML>"
2689;IfcLaborResource;"<EPM-HTML> 

<p>An <i>IfcLaborResource</i> is used in construction with particular skills or crafts required to perform certain types of construction or management related work. </p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0.  Base type and documentation extended in IFC 2x4.
</blockquote> 

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE: The attribute <i>Skillset</i> has been deleted; use LongDescription to describe the skillset.
</blockquote>

<p>The purpose of an <em>IfcLaborResource</em> is to identify a skillset that may be required or used. The skillset identified may be (for instance) chargehand, foreman, labourer, plumbers mate etc. and provides a designation of a particular level of skill. It can be used to identify the generic type of labor resource that is required for a purpose without having to be specific about the actor (person or organization) providing the resource occurrence. It may be particularly useful when creating an overall plan for a process or processes. For instance, within maintenance or work planning there may be a known task that needs to be done which is planned to require a 'chargehand pipe fitter'. There may be several such labor resources available and so the need to identify which will be used is not necessary at the planning stage.</p>

<p>At a later stage, individual actors can be determined for the labor resources. This is achieved through specifiying the actor through <em>IfcActor</em>. The actor is then identified as the labour resource occurrence through the <em>IfcRelAssignsToResource.RelatedResource</em> attribute. The <em>IfcLaborResource</em> provides the <em>IfcRelAssignsToResource</em>.<em>RelatingResource</em> attribute. </p>

<p>Use definitions for composition, assignment, constraints, time series, and baselines are described at the base type <i>IfcConstructionResource</i>.</p>

<p class=""use-head"">Type use definition</p>
<p><i>IfcLaborResource</i> defines the occurrence of any labor resource; common information about labor resource types is handled by <i>IfcLaborResourceType</i>.  The <i>IfcLaborResourceType</i> (if present) may establish the common type name, common properties, common productivities for various task types using <i>IfcRelAssignsToProcess</i>.  The <i>IfcLaborResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute.</p>
<p></p>

<p class=""use-head"">Quantity use definition</p>
<p>The quantities relating to the <i>IfcLaborResource</i> are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. It is accessible by the inverse <i>IsDefinedBy</i> relationship. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities can be defined being subjected to local standard of measurement with another string value assigned to <i>Name</i> and a value provided for <i>MethodOfMeasurement</i>.
<ul>
   <li><a href=""../../qto/IfcConstructionMgmtDomain/Qto_LaborResourceBaseQuantities.xml"" target=""SOURCE"">
   Qto_LaborResourceBaseQuantities</a>: base quantities for all labor resources.
   </li>
</ul>

<p class=""use-head"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResource</i>, a labor resource may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcLaborResource</i> and <i>RelatedObjects</i> contains one or more <i>IfcActor</i> subtypes as shown in Figure 194.  Such relationship indicates the specific people used as input for the resource.  Such actors are nested according to organizational structure with the root organization assigned to the <i>IfcProject</i>.  The <i>IfcActor</i> entity is used to represent the people or organizations.</p>

<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcLaborResource-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 194 &mdash; Labor resource assignment use</p></td></tr>
</table>

</EPM-HTML>"
2714;IfcCrewResource;"<EPM-HTML> 

<p><I>IfcCrewResource</I> represents a collection of internal resources used in construction processes.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0.  Base type and documentation extended in IFC2x4
</blockquote> 

<p>Identification of people and equipment of a crew is achieved through their specification at the level of the component. Therefore, knowing which persons are within a crew is achieved through identifying the persons assigned to each <i>IfcLaborResource</i> within the <i>IfcCrewResource</i>.  Similarly, identifying that a screwing machine for pipe fitting forms part of the crew is achieved by relating an appropriate instance of <i>IfcElementComponent</i> to the <i>IfcConstructionEquipmentResource</i> forming an element of the <i>IfcCrewResource</i>.</p>

<p>Use definitions for composition, assignment, constraints, time series, and baselines are described at the base type <i>IfcConstructionResource</i>.</p>

<p class=""use-head"">Type use definition</p>
<p><i>IfcCrewResource</i> defines the occurrence of any crew resource; common information about crew resource types is handled by <i>IfcCrewResourceType</i>.  The <i>IfcCrewResourceType</i> (if present) may establish the common type name, common properties, and common productivities for various task types using <i>IfcRelAssignsToProcess</i>.  The <i>IfcCrewResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute.</p>

</EPM-HTML>"
2722;IfcSubContractResource;"<EPM-HTML> 

<p><i>IfcSubContractResource</i> is a construction resource needed in a construction process that represents a sub-contractor. </p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0.  Base type and documentation extended in IFC 2x4.
</blockquote> 
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE: The attribute <i>SubContractor</i> has been deleted; use <i>IfcRelAssignsToResource</i> to assign an <i>IfcActor</i> to fulfill the role as the subcontractor.  The attribute <i>JobDescription</i> has been deleted; use <i>LongDescription</i> to describe the job.
</blockquote>

<p>An <i>IfcSubContractResource</i> can be used in cost estimating and work planning with or without specifying the subcontractor and contract agreement.</p> 
<p>The purpose of an <em>IfcSubContractResource</em> is to indicate work of a particular type that is that is to be engaged through the use of a sub-contract. It's aim is to identify the description of the sub-contract work required. It can be used to identify the generic type of sub-contract resource that is required for a purpose without having to be specific about the actor (person or organization) providing the resource occurrence. It may be particularly useful when creating an overall plan for a process or processes. For instance, within maintenance or work planning there may be a known task that needs to be done which is planned to require an 'insulation specialist'. </p>
<p>A subcontract resource may be described at various stages and levels of detail through its assignments:</p>
<ul>
<li>Subcontract resource designated for particular tasks</li>
<li>Actors identified to request bids</li>
<li>Cost schedules (bids) received from actors</li>
<li>Project order (work order, change order, etc.) executed</li>
</ul>

<p>Use definitions for composition, assignment, constraints, time series, and baselines are described at the base type <i>IfcConstructionResource</i>.</p>

<p class=""use-head"">Type use definition</p>
<p><i>IfcSubContractResource</i> defines the occurrence of any subcontract resource; common information about subcontract resource types is handled by <i>IfcSubContractResourceType</i>.  The <i>IfcSubContractResourceType</i> (if present) may establish the common type name, common properties, and common productivities for various task types using <i>IfcRelAssignsToProcess</i>.  The <i>IfcSubContractResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute.</p>
<p></p>

<p class=""use-head"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResource</i>, a subcontract resource may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcSubContractResource</i> and <i>RelatedObjects</i> contains one or more <i>IfcActor</i>, <i>IfcCostSchedule</i>, and/or <i>IfcWorkOrder</i> objects as shown in Figure 195.  An <i>IfcActor</i> indicates a specific organization to be considered to fulfill the resource or invited to bid on the resource.  An <i>IfcCostSchedule</i> indicates a bid or price quote made on behalf of an organization.  An <i>IfcProjectOrder</i> indicates a specific work order committed to fulfill the resource.</p>

<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcSubContractResource-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 195 &mdash; Subcontract assignment use</p></td></tr>
</table>

</EPM-HTML>"
2730;IfcConstructionProductResource;"<EPM-HTML> 

<p><i>IfcConstructionProductResource</i> defines the role of a product that is consumed (wholly or partially), or occupied in the performance of construction.</p> 
	 
<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0. Renamed from IfcProductResource in IFC 2x.  Base type and documentation extended in IFC2x4.
</blockquote> 

<p>Occurrences of <i>IfcConstructionProductResource</i> are usage of products to assist the process of construction. More specifically, they are usage of products that result from some construction processes and that are then used as resources to facilitate further construction. For instance, formworks can be instantiated as products resulting from the process &#145;constructing formwork&#146;. However, they are used as resources in the process &#145;pouring concrete&#146; in a later stage of the project. <i>IfcConstructionProductResource</i> occurrences  are explicitly instances of <i>IfcProduct</i> and may be drawn from various of the subtypes, for instance <em>IfcElementComponent</em>, <i>IfcElementAssembly</i>, <i>IfcProxy</i> (for particular cases where more precise usage details are not available).  The product that is used as a construction resource is referenced using the <i>IfcRelAssignsToResource.RelatedObjects</i> relationship.</P> 
		
<p>Use definitions for composition, assignment, constraints, time series, and baselines are described at the base type <i>IfcConstructionResource</i>.</p>

<p class=""use-head"">Type use definition</p>
<p><i>IfcConstructionProductResource</i> defines the occurrence of any product resource; common information about product resource types is handled by <i>IfcConstructionProductResourceType</i>.  The <i>IfcConstructionProductResourceType</i> (if present) may establish the common type name, common properties, and common productivities for various task types using <i>IfcRelAssignsToProcess</i>.  The <i>IfcConstructionProductResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute.</p>
<p></p>

<p class=""use-head"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResource</i>, a construction product resource may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionProductResource</i> and <i>RelatedObjects</i> contains one or more <i>IfcProduct</i> subtypes as shown in Figure 185.  Such relationship indicates the products used as input for the resource.  Such products are not contained within a building structure but are referenced within a construction spatial zone, specifically <i>IfcSpatialZone</i> with <i>PredefinedType=CONSTRUCTION</i>, which is aggregated within the <i>IfcProject</i>.  There may be multiple chains of production such that the assigned products may have their own task and resource assignments.</p>
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcConstructionProductResource-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 185 &mdash; Construction product resource assignment</p></td></tr>
</table>


</EPM-HTML>"
2738;IfcConstructionMaterialResource;"<EPM-HTML> 

<p><i>IfcConstructionMaterialResource</i> identifies a material resource type in a construction project.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0. Base type and documentation extended in IFC2x4.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 NOTE: The attribute <i>Suppliers</i> has been deleted; use <i>IfcRelAssignsToResource</i> to assign an <i>IfcActor</i> to fulfill the role as a supplier.  The attribute <i>UsageRatio</i> has been deleted; use <i>BaseQuantityConsumed</i> and <i>BaseQuantityProduced</i> to indicate material usage.
</blockquote>

<p>Occurrences of <i>IfcConstructionMaterialResource</i> are consumed (wholly or partially), or occupied during a construction work task (<i>IfcTask</i>).</p> 

<p>Similar to <i>IfcConstructionProductResource</i>, sometimes things such as 5000kg of gravel are already instantiated as an IfcProduct because it is a result of a work task (for example, &#145;transporting gravel&#146;). In this case, the instance of <i>IfcConstructionMaterialResource</i> can be associated with the product instance &#145;5000kg of gravel&#146; to provide more information for resource uses. Nevertheless, <I>IfcConstructionMaterialResource</I> should only be used to represent resource usage (for example &#145;gravel&#146;), but not product substances (for example, &#145;5000kg of gravel&#146;).</p> 
<p>Note: This class is not the same as <i>IfcMaterial</i>; the former can typically represent the type of bulk materials such as sand, gravels, nails and so on (note these can be instantiated from <i>IfcProduct</i> as well depending their uses in the system) used in a construction process. The latter is about physical materials used in a physical building element typically with detailed positioning (e.g. offset) and layering information.</p>
<p>Quantities for an <i>IfcConstructionMaterialResource</i> are defined through <I>IfcRelDefinesByProperty</I> and use <I>IfcElementQuantity</I>.</p>

<p>Use definitions for composition, assignment, constraints, time series, and baselines are described at the base type <i>IfcConstructionResource</i>.</p>

<p class=""use-head"">Type use definition</p>
<p><i>IfcConstructionMaterialResource</i> defines the occurrence of any material resource; common information about material resource types is handled by <i>IfcConstructionMaterialResourceType</i>.  The <i>IfcConstructionMaterialResourceType</i> (if present) may establish the common type name, common properties, and common productivities for various task types using <i>IfcRelAssignsToProcess</i>.  The <i>IfcConstructionMaterialResourceType</i> is attached using the <i>IfcRelDefinesByType.RelatingType</i> objectified relationship and is accessible by the inverse <i>IsTypedBy</i> attribute.</p>
<p></p>

<p class=""use-head"">Quantity use definition</p>
<p>The quantities relating to the <i>IfcConstructionMaterialResource</i> are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. It is accessible by the inverse <i>IsDefinedBy</i> relationship. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities can be defined being subjected to local standard of measurement with another string value assigned to <i>Name</i> and a value provided for <i>MethodOfMeasurement</i>.
<ul>
   <li><a href=""../../qto/IfcConstructionMgmtDomain/Qto_ConstructionMaterialResourceBaseQuantities.xml"" target=""SOURCE"">
   Qto_ConstructionMaterialResourceBaseQuantities</a>: base quantities for all construction material resources.
   </li>
</ul>

<p class=""use-head"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResource</i>, a construction material resource may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionMaterialResource</i> and <i>RelatedObjects</i> contains one or more <i>IfcProduct</i> subtypes as shown in Figure 184.  Such relationship indicates the physical material used as input for the resource.  Such products are not contained within a building structure but are referenced within a construction spatial zone, specifically <i>IfcSpatialZone</i> with <i>PredefinedType=CONSTRUCTION</i>, which is aggregated within the <i>IfcProject</i>.  The <i>IfcGeographicElement</i> object is used to represent the physical material occurrence, which may optionally have placement and representation indicating intended storage on the construction site.  There may be multiple chains of production such that the assigned product material(s) may have their own task and resource assignments for transporting or extracting such material.</p>
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcConstructionMaterialResource-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 184 &mdash; Construction material resource assignment</p></td></tr>
</table>

</EPM-HTML>"
2762;IfcConstructionResourceType;"<EPM-HTML>

<p><I>IfcConstructionResourceType</I> is an abstract generalization of the different resource types used in construction projects, mainly labor, material, equipment and product resource types, plus subcontracted resource types and aggregations such as a crew resource type.</p> 

<p>A resource type represents a model of ""use of something"" and does not necessarily correspond to a specific type of object such as a person or vehicle, but represents possible usages of such objects such as general labor or an equipment fleet.  A resource type can either represent usage in general (consumption attributes defined but no task type assignment) or a task-specific resource type (production attributes defined and having an <i>IfcTask</i> assignment).</p>

<p>A construction resource type captures common productivities and cost rates for applying resources to particular task types.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x4.
</blockquote>

<p class=""use-head"">Composition use definition</p>
<p>Resource types may be decomposed into nested resource types indicating productivities when applying the resource to specific task types using the <i>IfcRelNests</i> relationship where <i>IfcRelNests.RelatingObject</i> refers to the general resource type and <i>IfcRelNests.RelatedObjects</i> refers to one or more task-specific productivities.  For example, an <i>IfcLaborResourceType</i> may be defined for ""Carpenter"" which may have a nested <i>IfcLaborResourceType</i> for ""Carpenter - Wall Framing"" and another nested <i>IfcLaborResourceType</i> for ""Carpenter - Drywall"", each of which may have productivities based according to specific task types (<i>IfcTaskType</i>).</p> 

<p class=""use-head"">Assignment use definition</p>
<p>Resource types may be assigned to process types (<i>IfcTypeProcess</i> subtypes) using the <i>IfcRelAssignsToProcess</i> relationship as shown in Figure 193.  Such relationship indicates that the resource type applies to the process type for the use indicated (e.g. <i>IfcTaskType.PredefinedType</i>).  Such relationship enables a scenario of placing an <i>IfcProduct</i> of a particular <i>IfcTypeProduct</i>, querying for a set of <i>IfcTypeProcess</i> process types for constructing such product (e.g. <i>IfcTaskTypeEnum.CONSTRUCTION</i>), querying each <i>IfcTypeProcess</i> for a set of <i>IfcTypeResource</i> resource types for carrying out the process, and finally choosing an <i>IfcTypeProcess</i> and <i>IfcTypeResource</i> combination resulting in the shortest time for instantiated <i>IfcTask</i> occurrence(s) and/or lowest-cost for instantiated <i>IfcConstructionResource</i> occurrence(s).</p>
<table>
<tr><td><img alt=""Assignment Use Definition"" src=""figures/IfcConstructionResourceType-Assignment.png""></td></tr>
<tr><td><p class=""figure"">Figure 193 &mdash; Construction resource type assignment</p></td></tr>
</table>

</EPM-HTML>"
2774;IfcCrewResourceType;"<EPM-HTML>

<p>The resource type <i>IfcCrewResourceType</i> defines commonly shared information for occurrences of crew resources. The set of shared information may include:</p>
<ul>
<li>common productivities</li>
<li>common cost rates</li>
<li>common properties within shared property sets</li>
</ul>
<p>It is used to define a crew resource specification the specific resource information that is common to all occurrences of that resource). Resource types may be exchanged without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcCrewResourceType</i> are represented by instances of <i>IfcCrewResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
2777;IfcLaborResourceType;"<EPM-HTML>
<p>The resource type <i>IfcLaborResourceType</i> defines commonly shared information for occurrences of labor resources. The set of shared information may include:</p>
<ul>
<li>common productivities</li>
<li>common cost rates</li>
<li>common properties within shared property sets</li>
</ul>

<p>It is used to define a labor resource specification (i.e. the specific resource information that is common to all occurrences of that resource). Resource types may be exchanged without being already assigned to occurrences.</p>

<p>Occurrences of the <i>IfcLaborResourceType</i> are represented by instances of <i>IfcLaborResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
2780;IfcSubContractResourceType;"<EPM-HTML>

<p>The resource type <i>IfcSubContractResourceType</i> defines commonly shared information for occurrences of subcontract resources. The set of shared information may include:</p>
<ul>
<li>common productivities</li>
<li>common cost rates</li>
<li>common properties within shared property sets</li>
</ul>
<p>It is used to define a subcontract resource specification (the specific resource information that is common to all
occurrences of that resource). Resource types may be exchanged without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcSubContractResourceType</i> are represented by instances of <i>IfcSubContractResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
2783;IfcConstructionMaterialResourceType;"<EPM-HTML>
<p>The resource type <i>IfcConstructionMaterialType</i> defines commonly shared information for occurrences of construction material resources. The set of shared information may include:</p>
<ul>
<li>common productivities</li>
<li>common cost rates</li>
<li>common properties within shared property sets</li>
</ul>
<p>It is used to define a construction material resource specification (i.e. the specific resource information that is common to all occurrences of that resource). Resource types may be exchanged without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcConstructionMaterialResourceType</i> are represented by instances of <i>IfcConstructionMaterialResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""head-use"">Assignment Use Definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResourceType</i>, a construction material resource type may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionMaterialResourceType</i> and <i>RelatedObjects</i> contains one or more <i>IfcTypeProduct</i> subtypes.  Such relationship indicates material specifications to be used as input, which is instantiated as an occurrence assigned for each resource occurrence.  The <i>IfcGeographicElementType</i> product type may be used to hold the material representation (via <i>IfcRelAssociatesMaterial</i>. There may be multiple chains of production where such product type may have its own task and resource types assigned indicating how to transport or extract such material.</p>

</EPM-HTML>"
2786;IfcConstructionEquipmentResourceType;"<EPM-HTML>

<p>The resource type <i>IfcConstructionEquipmentType</i> defines commonly shared information for occurrences of construction equipment resources. The set of shared information may include:</p>
<ul>
<li>common productivities</li>
<li>common cost rates</li>
<li>common properties within shared property sets</li>
</ul>
<p>It is used to define a construction equipment resource specification (the specific resource information that is common to all occurrences of that resource). Resource types may be exchanged without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcConstructionEquipmentResourceType</i> are represented by instances of <i>IfcConstructionEquipmentResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""head-use"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResourceType</i>, a construction equipment resource type may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionEquipmentResourceType</i> and <i>RelatedObjects</i> contains one or more <i>IfcTypeProduct</i> subtypes.  Such relationship indicates the type of equipment to be used as input, which is instantiated as an occurrence assigned for each resource occurrence.  There may be multiple chains of production where such product type may have its own task and resource types assigned indicating how to assemble such equipment.</p>

</EPM-HTML>"
2789;IfcConstructionProductResourceType;"<EPM-HTML>

<p>The resource type <i>IfcConstructionProductType</i> defines commonly shared information for occurrences of construction product resources. The set of shared information may include:</p>
<ul>
<li>common productivities</li>
<li>common cost rates</li>
<li>common properties within shared property sets</li>
</ul>
<p>It is used to define a construction product resource specification (i.e. the specific resource information that is common to all occurrences of that resource). Resource types may be exchanged without being already assigned to occurrences.</p>
<p>Occurrences of the <i>IfcConstructionProductResourceType</i> are represented by instances of <i>IfcConstructionProductResource</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p class=""head-use"">Assignment use definition</p>
<p>In addition to assignments specified at the base class <i>IfcConstructionResourceType</i>, a construction product resource type may have assignments of its own using <i>IfcRelAssignsToResource</i> where <i>RelatingResource</i> refers to the <i>IfcConstructionProductResourceType</i> and <i>RelatedObjects</i> contains one or more <i>IfcTypeProduct</i> subtypes.  Such relationship indicates the type of product to be used as input, which is instantiated as an occurrence assigned for each resource occurrence.  There may be multiple chains of production where such product type may have its own task and resource types assigned.</p>

</EPM-HTML>"
2793;IfcMotorConnectionType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcMotorConnectionType</b> defines commonly shared information for occurrences of motor connections.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a motor connection specification (i.e. the specific product information, that is common to all occurrences of that product type).  Motor Connection types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcMotorConnectionType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcmotorconnection.htm"">IfcMotorConnection</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_MotorConnectionTypeCommon.xml"" target=""SOURCE"">Pset_MotorConnectionTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcMotorConnectionType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcMotorConnectionType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcmotorconnection.htm"">IfcMotorConnection</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2796;IfcOutletType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcOutletType</b> defines commonly shared information for occurrences of outlets.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a outlet specification (i.e. the specific product information, that is common to all occurrences of that product type).  Outlet types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcOutletType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcoutlet.htm"">IfcOutlet</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_OutletTypeCommon.xml"" target=""SOURCE"">Pset_OutletTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcOutletType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Conductor'</b>: Material from which the conductors are constructed.</li> 
<li><b>'Surface'</b>: Material from which the outlet plate is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcOutletType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcoutlet.htm"">IfcOutlet</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2807;IfcElectricApplianceType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcElectricApplianceType</b> defines commonly shared information for occurrences of electric appliances.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a electric appliance specification (i.e. the specific product information, that is common to all occurrences of that product type).  Electric Appliance types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcElectricApplianceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcelectricappliance.htm"">IfcElectricAppliance</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricApplianceTypeCommon.xml"" target=""SOURCE"">Pset_ElectricApplianceTypeCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricApplianceTypeDishwasher.xml"" target=""SOURCE"">Pset_ElectricApplianceTypeDishwasher</a> (<a href=""../../ifcelectricaldomain/lexical/ifcelectricappliancetypeenum.htm"">DISHWASHER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricApplianceTypeElectricCooker.xml"" target=""SOURCE"">Pset_ElectricApplianceTypeElectricCooker</a> (<a href=""../../ifcelectricaldomain/lexical/ifcelectricappliancetypeenum.htm"">ELECTRICCOOKER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcElectricApplianceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcElectricApplianceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcelectricappliance.htm"">IfcElectricAppliance</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2829;IfcLightFixtureType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcLightFixtureType</b> defines commonly shared information for occurrences of light fixtures.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a light fixture specification (i.e. the specific product information, that is common to all occurrences of that product type).  Light Fixture types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcLightFixtureType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifclightfixture.htm"">IfcLightFixture</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_LightFixtureTypeCommon.xml"" target=""SOURCE"">Pset_LightFixtureTypeCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_LightFixtureTypeThermal.xml"" target=""SOURCE"">Pset_LightFixtureTypeThermal</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_LightFixtureTypeSecurityLighting.xml"" target=""SOURCE"">Pset_LightFixtureTypeSecurityLighting</a> (<a href=""../../ifcelectricaldomain/lexical/ifclightfixturetypeenum.htm"">SECURITYLIGHTING</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcLightFixtureType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcLightFixtureType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifclightfixture.htm"">IfcLightFixture</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2838;IfcLampType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcLampType</b> defines commonly shared information for occurrences of lamps.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a lamp specification (i.e. the specific product information, that is common to all occurrences of that product type).  Lamp types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcLampType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifclamp.htm"">IfcLamp</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_LampTypeCommon.xml"" target=""SOURCE"">Pset_LampTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcLampType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Bulb'</b>: Material from which the bulb is constructed (e.g. glass).</li> 
<li><b>'Conductor'</b>: Material from which the conductor is constructed.</li> 
<li><b>'Filament'</b>: Material from which the filament is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcLampType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifclamp.htm"">IfcLamp</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2853;IfcAudioVisualApplianceType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcAudioVisualApplianceType</b> defines commonly shared information for occurrences of audio-visual appliances.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a audio-visual appliance specification (i.e. the specific product information, that is common to all occurrences of that product type).  Audio-Visual Appliance types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcAudioVisualApplianceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliance.htm"">IfcAudioVisualAppliance</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeCommon.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeAmplifier.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeAmplifier</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">AMPLIFIER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeCamera.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeCamera</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">CAMERA</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeDisplay.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeDisplay</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">DISPLAY</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypePlayer.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypePlayer</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">PLAYER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeProjector.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeProjector</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">PROJECTOR</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeReceiver.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeReceiver</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">RECEIVER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeSpeaker.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeSpeaker</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">SPEAKER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_AudioVisualApplianceTypeTuner.xml"" target=""SOURCE"">Pset_AudioVisualApplianceTypeTuner</a> (<a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliancetypeenum.htm"">TUNER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcAudioVisualApplianceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcAudioVisualApplianceType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcAudioVisualApplianceType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliance.htm"">IfcAudioVisualAppliance</a> components.  </li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcAudioVisualApplianceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliance.htm"">IfcAudioVisualAppliance</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2870;IfcCommunicationsApplianceType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcCommunicationsApplianceType</b> defines commonly shared information for occurrences of communications appliances.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a communications appliance specification (i.e. the specific product information, that is common to all occurrences of that product type).  Communications Appliance types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCommunicationsApplianceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifccommunicationsappliance.htm"">IfcCommunicationsAppliance</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CommunicationsApplianceTypeCommon.xml"" target=""SOURCE"">Pset_CommunicationsApplianceTypeCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCommunicationsApplianceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcCommunicationsApplianceType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcCommunicationsApplianceType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifcelectricaldomain/lexical/ifccommunicationsappliancetypeenum.htm"">COMPUTER</a>: May contain <a href=""../../ifcelectricaldomain/lexical/ifcaudiovisualappliance.htm"">IfcAudioVisualAppliance</a> components.  Computers may be aggregated into audio-visual components such as displays, cameras, speakers, or microphones.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCommunicationsApplianceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifccommunicationsappliance.htm"">IfcCommunicationsAppliance</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2888;IfcSwitchingDeviceType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcSwitchingDeviceType</b> defines commonly shared information for occurrences of switching devices.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a switching device specification (i.e. the specific product information, that is common to all occurrences of that product type).  Switching Device types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcSwitchingDeviceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevice.htm"">IfcSwitchingDevice</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeCommon.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeContactor.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeContactor</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">CONTACTOR</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeDimmerSwitch.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeDimmerSwitch</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">DIMMERSWITCH</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeEmergencyStop.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeEmergencyStop</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">EMERGENCYSTOP</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeKeypad.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeKeypad</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">KEYPAD</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeMomentarySwitch.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeMomentarySwitch</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">MOMENTARYSWITCH</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeSelectorSwitch.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeSelectorSwitch</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">SELECTORSWITCH</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeStarter.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeStarter</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">STARTER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeSwitchDisconnector.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeSwitchDisconnector</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">SWITCHDISCONNECTOR</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SwitchingDeviceTypeToggleSwitch.xml"" target=""SOURCE"">Pset_SwitchingDeviceTypeToggleSwitch</a> (<a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevicetypeenum.htm"">TOGGLESWITCH</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSwitchingDeviceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Conductor'</b>: Material from which the conductors are constructed.</li> 
<li><b>'Surface'</b>: Material from which the switch surface is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcSwitchingDeviceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcswitchingdevice.htm"">IfcSwitchingDevice</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2903;IfcElectricTimeControlType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcElectricTimeControlType</b> defines commonly shared information for occurrences of electric time controls.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a electric time control specification (i.e. the specific product information, that is common to all occurrences of that product type).  Electric Time Control types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcElectricTimeControlType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcelectrictimecontrol.htm"">IfcElectricTimeControl</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricTimeControlTypeCommon.xml"" target=""SOURCE"">Pset_ElectricTimeControlTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcElectricTimeControlType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcElectricTimeControlType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcelectrictimecontrol.htm"">IfcElectricTimeControl</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2912;IfcProtectiveDeviceType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcProtectiveDeviceType</b> defines commonly shared information for occurrences of protective devices.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a protective device specification (i.e. the specific product information, that is common to all occurrences of that product type).  Protective Device types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcProtectiveDeviceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevice.htm"">IfcProtectiveDevice</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeCommon.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeCircuitBreaker.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeCircuitBreaker</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetypeenum.htm"">CIRCUITBREAKER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeEarthLeakageCircuitBreaker.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeEarthLeakageCircuitBreaker</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetypeenum.htm"">EARTHLEAKAGECIRCUITBREAKER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeFuseDisconnector.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeFuseDisconnector</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetypeenum.htm"">FUSEDISCONNECTOR</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeResidualCurrentCircuitBreaker.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeResidualCurrentCircuitBreaker</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetypeenum.htm"">RESIDUALCURRENTCIRCUITBREAKER</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeResidualCurrentSwitch.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeResidualCurrentSwitch</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetypeenum.htm"">RESIDUALCURRENTSWITCH</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTypeVaristor.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTypeVaristor</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetypeenum.htm"">VARISTOR</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcProtectiveDeviceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcProtectiveDeviceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevice.htm"">IfcProtectiveDevice</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2925;IfcElectricDistributionBoardType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcElectricDistributionBoardType</b> defines commonly shared information for occurrences of distribution boards.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a distribution board specification (i.e. the specific product information, that is common to all occurrences of that product type).  Distribution Board types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcElectricDistributionBoardType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcelectricdistributionboard.htm"">IfcElectricDistributionBoard</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricDistributionBoardTypeCommon.xml"" target=""SOURCE"">Pset_ElectricDistributionBoardTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcElectricDistributionBoardType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcElectricDistributionBoardType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcelectricdistributionboard.htm"">IfcElectricDistributionBoard</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2935;IfcCableCarrierFittingType;"<EPM-HTML> 
 
<p>The flow fitting type <b>IfcCableCarrierFittingType</b> defines commonly shared information for occurrences of cable carrier fittings.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a cable carrier fitting specification (i.e. the specific product information, that is common to all occurrences of that product type).  Cable Carrier Fitting types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCableCarrierFittingType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifccablecarrierfitting.htm"">IfcCableCarrierFitting</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowfittingtype.htm"">IfcFlowFittingType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableCarrierFittingTypeCommon.xml"" target=""SOURCE"">Pset_CableCarrierFittingTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCableCarrierFittingType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCableCarrierFittingType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifccablecarrierfitting.htm"">IfcCableCarrierFitting</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2945;IfcJunctionBoxType;"<EPM-HTML> 
 
<p>The flow fitting type <b>IfcJunctionBoxType</b> defines commonly shared information for occurrences of junction boxs.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a junction box specification (i.e. the specific product information, that is common to all occurrences of that product type).  Junction Box types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcJunctionBoxType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcjunctionbox.htm"">IfcJunctionBox</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowfittingtype.htm"">IfcFlowFittingType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_JunctionBoxTypeCommon.xml"" target=""SOURCE"">Pset_JunctionBoxTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcJunctionBoxType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcJunctionBoxType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcjunctionbox.htm"">IfcJunctionBox</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2953;IfcCableFittingType;"<EPM-HTML> 
 
<p>The flow fitting type <b>IfcCableFittingType</b> defines commonly shared information for occurrences of cable fittings.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a cable fitting specification (i.e. the specific product information, that is common to all occurrences of that product type).  Cable Fitting types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCableFittingType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifccablefitting.htm"">IfcCableFitting</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowfittingtype.htm"">IfcFlowFittingType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableFittingTypeCommon.xml"" target=""SOURCE"">Pset_CableFittingTypeCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCableFittingType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Conductor'</b>: Material from which the conductors are constructed, such as Aluminium or Copper.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCableFittingType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifccablefitting.htm"">IfcCableFitting</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2964;IfcElectricFlowStorageDeviceType;"<EPM-HTML> 
 
<p>The flow storage device type <b>IfcElectricFlowStorageDeviceType</b> defines commonly shared information for occurrences of electric flow storage devices.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a electric flow storage device specification (i.e. the specific product information, that is common to all occurrences of that product type).  Electric Flow Storage Device types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcElectricFlowStorageDeviceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcelectricflowstoragedevice.htm"">IfcElectricFlowStorageDevice</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowstoragedevicetype.htm"">IfcFlowStorageDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricFlowStorageDeviceTypeCommon.xml"" target=""SOURCE"">Pset_ElectricFlowStorageDeviceTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcElectricFlowStorageDeviceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcElectricFlowStorageDeviceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcelectricflowstoragedevice.htm"">IfcElectricFlowStorageDevice</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2975;IfcCableSegmentType;"<EPM-HTML> 
 
<p>The flow segment type <b>IfcCableSegmentType</b> defines commonly shared information for occurrences of cable segments.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a cable segment specification (i.e. the specific product information, that is common to all occurrences of that product type).  Cable Segment types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCableSegmentType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifccablesegment.htm"">IfcCableSegment</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowsegmenttype.htm"">IfcFlowSegmentType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableSegmentTypeCommon.xml"" target=""SOURCE"">Pset_CableSegmentTypeCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableSegmentTypeBusbarSegment.xml"" target=""SOURCE"">Pset_CableSegmentTypeBusbarSegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">BUSBARSEGMENT</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableSegmentTypeCableSegment.xml"" target=""SOURCE"">Pset_CableSegmentTypeCableSegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">CABLESEGMENT</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableSegmentTypeConductorSegment.xml"" target=""SOURCE"">Pset_CableSegmentTypeConductorSegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">CONDUCTORSEGMENT</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCableSegmentType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Conductor'</b>: The material from which the conductor is constructed such as Aluminium or Copper.</li> 
<li><b>'Insulation'</b>: The material from which the insulation is constructed such as PVC, PEX, EPR, etc.</li> 
<li><b>'Screen'</b>: The material from which the screen that covers the sheath is constructed (mantel) such as Aluminium, Copper, Steel , Lead.</li> 
<li><b>'Sheath'</b>: The outer sheathing of the cable which may be color-coded.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcCableSegmentType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcCableSegmentType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">CABLESEGMENT</a>: May contain <a href=""../../ifcelectricaldomain/lexical/ifccablesegment.htm"">IfcCableSegment</a> components having <i>PredefinedType</i> <a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">CORESEGMENT</a>.  Cable segments may be aggregated into cable cores.</li> 
<li><a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">CORESEGMENT</a>: May contain <a href=""../../ifcelectricaldomain/lexical/ifccablesegment.htm"">IfcCableSegment</a> components having <i>PredefinedType</i> <a href=""../../ifcelectricaldomain/lexical/ifccablesegmenttypeenum.htm"">CONDUCTORSEGMENT</a>.  Cable cores may be aggregated into cable conductors.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCableSegmentType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifccablesegment.htm"">IfcCableSegment</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2985;IfcCableCarrierSegmentType;"<EPM-HTML> 
 
<p>The flow segment type <b>IfcCableCarrierSegmentType</b> defines commonly shared information for occurrences of cable carrier segments.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a cable carrier segment specification (i.e. the specific product information, that is common to all occurrences of that product type).  Cable Carrier Segment types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCableCarrierSegmentType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegment.htm"">IfcCableCarrierSegment</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowsegmenttype.htm"">IfcFlowSegmentType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableCarrierSegmentTypeCommon.xml"" target=""SOURCE"">Pset_CableCarrierSegmentTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableCarrierSegmentTypeCableLadderSegment.xml"" target=""SOURCE"">Pset_CableCarrierSegmentTypeCableLadderSegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegmenttypeenum.htm"">CABLELADDERSEGMENT</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableCarrierSegmentTypeCableTraySegment.xml"" target=""SOURCE"">Pset_CableCarrierSegmentTypeCableTraySegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegmenttypeenum.htm"">CABLETRAYSEGMENT</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableCarrierSegmentTypeCableTrunkingSegment.xml"" target=""SOURCE"">Pset_CableCarrierSegmentTypeCableTrunkingSegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegmenttypeenum.htm"">CABLETRUNKINGSEGMENT</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_CableCarrierSegmentTypeConduitSegment.xml"" target=""SOURCE"">Pset_CableCarrierSegmentTypeConduitSegment</a> (<a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegmenttypeenum.htm"">CONDUITSEGMENT</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCableCarrierSegmentType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: Material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCableCarrierSegmentType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegment.htm"">IfcCableCarrierSegment</a> for standard port definitions.</p> 
 
</EPM-HTML>"
2995;IfcProtectiveDeviceTrippingUnitType;"<EPM-HTML> 
 
<p>The distribution control element type <b>IfcProtectiveDeviceTrippingUnitType</b> defines commonly shared information for occurrences of protective device tripping units.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a protective device tripping unit specification (i.e. the specific product information, that is common to all occurrences of that product type).  Protective Device Tripping Unit types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcProtectiveDeviceTrippingUnitType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetrippingunit.htm"">IfcProtectiveDeviceTrippingUnit</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm"">IfcDistributionControlElementType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingCurve.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingCurve</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingFunctionGCurve.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingFunctionGCurve</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingFunctionICurve.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingFunctionICurve</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingFunctionLCurve.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingFunctionLCurve</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingFunctionSCurve.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingFunctionSCurve</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitCurrentAdjustment.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitCurrentAdjustment</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitTimeAdjustment.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitTimeAdjustment</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitTypeCommon.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitTypeElectroMagnetic.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitTypeElectroMagnetic</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetrippingunittypeenum.htm"">ELECTROMAGNETIC</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitTypeElectronic.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitTypeElectronic</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetrippingunittypeenum.htm"">ELECTRONIC</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitTypeResidualCurrent.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitTypeResidualCurrent</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetrippingunittypeenum.htm"">RESIDUALCURRENT</a>)</li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ProtectiveDeviceTrippingUnitTypeThermal.xml"" target=""SOURCE"">Pset_ProtectiveDeviceTrippingUnitTypeThermal</a> (<a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetrippingunittypeenum.htm"">THERMAL</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcProtectiveDeviceTrippingUnitType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcProtectiveDeviceTrippingUnitType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcprotectivedevicetrippingunit.htm"">IfcProtectiveDeviceTrippingUnit</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3005;IfcCableSegment;"<p>A cable segment is a flow segment used to carry electrical power, data, or telecommunications signals.</p>
<p>A cable segment is used to typically join two sections of an electrical network or a network of components carrying the electrical service.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCableSegment</b> defines the occurrence of any cable segment; common information about cable segment types is handled by <i>IfcCableSegmentType</i>. 
The <i>IfcCableSegmentType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCableSegmentType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCableSegmentType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCableSegment</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCableSegmentType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCableSegmentType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCableSegment</b> override the properties defined at <i>IfcCableSegmentType</i>. 
Refer to the documentation at the supertype <i>IfcFlowSegment</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableSegmentTypeCommon.xml"">Pset_CableSegmentTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablesegmenttypeenum.htm"">BUSBARSEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableSegmentTypeBusBarSegment.xml"">Pset_CableSegmentTypeBusBarSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablesegmenttypeenum.htm"">CABLESEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableSegmentTypeCableSegment.xml"">Pset_CableSegmentTypeCableSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablesegmenttypeenum.htm"">CONDUCTORSEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableSegmentTypeConductorSegment.xml"">Pset_CableSegmentTypeConductorSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablesegmenttypeenum.htm"">CORESEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableSegmentTypeCoreSegment.xml"">Pset_CableSegmentTypeCoreSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_CableSegmentBaseQuantities.xml"">Qto_CableSegmentBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCableSegment</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCableSegmentType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Conductor</b>: Material from which the conductors are constructed, such as Aluminium or Copper.</li>
<li><b>Insulation</b>: The material from which the insulation is constructed such as PVC, PEX, or EPR.</li>
<li><b>Screen</b>: The material from which the screen that covers the sheath is constructed (mantel) such as Aluminium, Copper, Steel, or Lead.</li>
<li><b>Sheath</b>: The outer sheathing of the cable which may be color-coded.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcCableSegment</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcCableSegment</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li><a href=""./ifccablesegmenttypeenum.htm"">CABLESEGMENT</a>
<ul>
<li>May contain <i>IfcCableSegment</i> components having <i>PredefinedType=CORESEGMENT</i>. Cable segments may be aggregated into cable cores.</li>
</ul>
</li>
<li><a href=""./ifccablesegmenttypeenum.htm"">CORESEGMENT</a>
<ul>
<li>May contain <i>IfcCableSegment</i> components having <i>PredefinedType=CONDUCTORSEGMENT</i>. Cable cores may be aggregated into cable conductors.</li>
</ul>
</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcCableSegment</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcelectricaldomain/lexical/ifccablecarriersegment.htm"">IfcCableCarrierSegment</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Indicates a cable carrier segment housing the cable. </li>
<li><b><a href=""../../ifcsharedbldgelements/lexical/ifcwall.htm"">IfcWall</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Indicates a wall housing the cable.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCableSegment</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the cable segment occurrence is defined by <i>IfcCableSegmentType</i>, then the port occurrences must reflect those defined at the <i>IfcCableSegmentType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCableSegment</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccablesegmenttypeenum.htm"">CABLESEGMENT</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input end of the cable.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output end of the cable.</li>
</ul>
</li>
<li><a href=""./ifccablesegmenttypeenum.htm"">CONDUCTORSEGMENT</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input end of the conductor.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output end of the cable.</li>
</ul>
</li>
</ul>

"
3009;IfcCableCarrierSegment;"<p>A cable carrier segment is a flow segment that is specifically used to carry and support cabling.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCableCarrierSegment</b> defines the occurrence of any cable carrier segment; common information about cable carrier segment types is handled by <i>IfcCableCarrierSegmentType</i>. 
The <i>IfcCableCarrierSegmentType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCableCarrierSegmentType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCableCarrierSegmentType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCableCarrierSegment</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCableCarrierSegmentType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCableCarrierSegmentType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCableCarrierSegment</b> override the properties defined at <i>IfcCableCarrierSegmentType</i>. 
Refer to the documentation at the supertype <i>IfcFlowSegment</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableCarrierSegmentTypeCommon.xml"">Pset_CableCarrierSegmentTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablecarriersegmenttypeenum.htm"">CABLELADDERSEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableCarrierSegmentTypeCableLadderSegment.xml"">Pset_CableCarrierSegmentTypeCableLadderSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablecarriersegmenttypeenum.htm"">CABLETRAYSEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableCarrierSegmentTypeCableTraySegment.xml"">Pset_CableCarrierSegmentTypeCableTraySegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablecarriersegmenttypeenum.htm"">CABLETRUNKINGSEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableCarrierSegmentTypeCableTrunkingSegment.xml"">Pset_CableCarrierSegmentTypeCableTrunkingSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccablecarriersegmenttypeenum.htm"">CONDUITSEGMENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableCarrierSegmentTypeConduitSegment.xml"">Pset_CableCarrierSegmentTypeConduitSegment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_CableCarrierSegmentBaseQuantities.xml"">Qto_CableCarrierSegmentBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCableCarrierSegment</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCableCarrierSegmentType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCableCarrierSegment</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the cable carrier segment occurrence is defined by <i>IfcCableCarrierSegmentType</i>, then the port occurrences must reflect those defined at the <i>IfcCableCarrierSegmentType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCableCarrierSegment</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Head</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Head connection.</li>
<li><b>Tail</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Tail connection.</li>
</ul>

"
3013;IfcCableCarrierFitting;"<p>A cable carrier fitting is a fitting that is placed at junction or transition in a cable carrier system.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCableCarrierFitting</b> defines the occurrence of any cable carrier fitting; common information about cable carrier fitting types is handled by <i>IfcCableCarrierFittingType</i>. 
The <i>IfcCableCarrierFittingType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCableCarrierFittingType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCableCarrierFittingType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCableCarrierFitting</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCableCarrierFittingType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCableCarrierFittingType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCableCarrierFitting</b> override the properties defined at <i>IfcCableCarrierFittingType</i>. 
Refer to the documentation at the supertype <i>IfcFlowFitting</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableCarrierFittingTypeCommon.xml"">Pset_CableCarrierFittingTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_CableCarrierFittingBaseQuantities.xml"">Qto_CableCarrierFittingBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCableCarrierFitting</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCableCarrierFittingType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCableCarrierFitting</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the cable carrier fitting occurrence is defined by <i>IfcCableCarrierFittingType</i>, then the port occurrences must reflect those defined at the <i>IfcCableCarrierFittingType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCableCarrierFitting</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccablecarrierfittingtypeenum.htm"">BEND</a>
<ul>
<li><b>Head</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Head connection.</li>
<li><b>Tail</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Tail connection.</li>
</ul>
</li>
<li><a href=""./ifccablecarrierfittingtypeenum.htm"">CROSS</a>
<ul>
<li><b>Head</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Head connection.</li>
<li><b>Tail</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Tail connection.</li>
<li><b>Left</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Left connection.</li>
<li><b>Right</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Right connection.</li>
</ul>
</li>
<li><a href=""./ifccablecarrierfittingtypeenum.htm"">REDUCER</a>
<ul>
<li><b>Head</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Head connection.</li>
<li><b>Tail</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Tail connection.</li>
</ul>
</li>
<li><a href=""./ifccablecarrierfittingtypeenum.htm"">TEE</a>
<ul>
<li><b>Head</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Head connection.</li>
<li><b>Left</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Left connection.</li>
<li><b>Right</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Right connection.</li>
</ul>
</li>
</ul>

"
3017;IfcCableFitting;"<p>A cable fitting is a fitting that is placed at a junction, transition or termination in a cable system.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCableFitting</b> defines the occurrence of any cable fitting; common information about cable fitting types is handled by <i>IfcCableFittingType</i>. 
The <i>IfcCableFittingType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCableFittingType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCableFittingType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCableFitting</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCableFittingType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCableFittingType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCableFitting</b> override the properties defined at <i>IfcCableFittingType</i>. 
Refer to the documentation at the supertype <i>IfcFlowFitting</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CableFittingTypeCommon.xml"">Pset_CableFittingTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_CableFittingBaseQuantities.xml"">Qto_CableFittingBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCableFitting</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCableFittingType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
<li><b>Conductor</b>: Material from which the conductors are constructed, such as Aluminium or Copper.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcCableFitting</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href=""./ifccablefittingtypeenum.htm"">ENTRY</a>
<ul>
<li><b><a href=""../../ifchvacdomain/lexical/ifcpipesegment.htm"">IfcPipeSegment</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): For equipotential bonding, may represent a clamp that is attached from a pipe or other conducting element of an earthing system.</li>
</ul>
</li>
<li><a href=""./ifccablefittingtypeenum.htm"">EXIT</a>
<ul>
<li><b><a href=""../../ifchvacdomain/lexical/ifcpipesegment.htm"">IfcPipeSegment</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): For equipotential bonding, may represent a clamp that is attached to a pipe or other conducting element of an earthing system.</li>
</ul>
</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCableFitting</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the cable fitting occurrence is defined by <i>IfcCableFittingType</i>, then the port occurrences must reflect those defined at the <i>IfcCableFittingType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCableFitting</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccablefittingtypeenum.htm"">CONNECTOR</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The input of the connector.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The output of the connector.</li>
</ul>
</li>
<li><a href=""./ifccablefittingtypeenum.htm"">ENTRY</a>
<ul>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The output of the connector.</li>
</ul>
</li>
<li><a href=""./ifccablefittingtypeenum.htm"">EXIT</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The input of the connector.</li>
</ul>
</li>
<li><a href=""./ifccablefittingtypeenum.htm"">JUNCTION</a>
<ul>
<li><b>Head</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The input of the connector.</li>
<li><b>Output#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): An output of the connector.</li>
<li><b>Output#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): An output of the connector.</li>
</ul>
</li>
<li><a href=""./ifccablefittingtypeenum.htm"">TRANSITION</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The input of the connector.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The output of the connector.</li>
</ul>
</li>
</ul>

"
3021;IfcJunctionBox;"<p>A junction box is an enclosure within which cables are connected.</p>
<p>Cables may be members of an electrical circuit (for electrical power systems) or be information carriers (in a telecommunications system). A junction box is typically intended to conceal a cable junction from sight, eliminate tampering or provide a safe place for electrical connection.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcJunctionBox</b> defines the occurrence of any junction box; common information about junction box types is handled by <i>IfcJunctionBoxType</i>. 
The <i>IfcJunctionBoxType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcJunctionBoxType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcJunctionBoxType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcJunctionBox</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 200 illustrates junction box type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcjunctionbox-Type.png""></td></tr><tr><td><p class=""figure"">Figure 200 &mdash; Junction box type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcJunctionBoxType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcJunctionBoxType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcJunctionBox</b> override the properties defined at <i>IfcJunctionBoxType</i>. 
Refer to the documentation at the supertype <i>IfcFlowFitting</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_JunctionBoxTypeCommon.xml"">Pset_JunctionBoxTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_JunctionBoxBaseQuantities.xml"">Qto_JunctionBoxBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcJunctionBox</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcJunctionBoxType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcJunctionBox</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcsharedcomponentelements/lexical/ifcdiscreteaccessory.htm"">IfcDiscreteAccessory</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Indicates a cover plate for the junction box, having ObjectType 'JunctionBoxCoverPlate'.</li>
<li><b><a href=""../../ifcproductextension/lexical/ifcopeningelement.htm"">IfcOpeningElement</a></b> (IfcRelFillsElements): Indicates embedding the junction box in a building element such as a wall.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcJunctionBox</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the junction box occurrence is defined by <i>IfcJunctionBoxType</i>, then the port occurrences must reflect those defined at the <i>IfcJunctionBoxType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcJunctionBox</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcjunctionboxtypeenum.htm"">DATA</a>
<ul>
<li><b>Line#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A data line, typically a cable connecting from a network router communications device.</li>
<li><b>Line#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A data line, typically a cable connecting from a network router communications device.</li>
<li><b>Gang#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A slot to house a data outlet containing one or more jacks, ordered from left-to-right.</li>
<li><b>Gang#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A slot to house a data outlet containing one or more jacks, ordered from left-to-right.</li>
</ul>
</li>
<li><a href=""./ifcjunctionboxtypeenum.htm"">POWER</a>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The electrical supply line, typically a cable connecting from another junction box or from a protective device within a distribution board.</li>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The next load in the circuit, typically a cable connecting to another junction box.</li>
<li><b>Gang#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A slot to house a switch or outlet, ordered from left-to-right.</li>
<li><b>Gang#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A slot to house a switch or outlet, ordered from left-to-right.</li>
<li><b>Gang#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A slot to house a switch or outlet, ordered from left-to-right.</li>
<li><b>Gang#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A slot to house a switch or outlet, ordered from left-to-right.</li>
</ul>
</li>
</ul>
<p>Figure 201 illustrates junction box port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcjunctionbox-Port.png""></td></tr><tr><td><p class=""figure"">Figure 201 &mdash; Junction box port use</p></td></tr></table>


"
3025;IfcElectricFlowStorageDevice;"<p>An electric flow storage device is a device in which electrical energy is stored and from which energy may be progressively released.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcElectricFlowStorageDevice</b> defines the occurrence of any electric flow storage device; common information about electric flow storage device types is handled by <i>IfcElectricFlowStorageDeviceType</i>. 
The <i>IfcElectricFlowStorageDeviceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcElectricFlowStorageDeviceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcElectricFlowStorageDeviceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcElectricFlowStorageDevice</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcElectricFlowStorageDeviceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcElectricFlowStorageDeviceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcElectricFlowStorageDevice</b> override the properties defined at <i>IfcElectricFlowStorageDeviceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowStorageDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricFlowStorageDeviceTypeCommon.xml"">Pset_ElectricFlowStorageDeviceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ElectricFlowStorageDeviceBaseQuantities.xml"">Qto_ElectricFlowStorageDeviceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcElectricFlowStorageDevice</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcElectricFlowStorageDeviceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcElectricFlowStorageDevice</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the electric flow storage device occurrence is defined by <i>IfcElectricFlowStorageDeviceType</i>, then the port occurrences must reflect those defined at the <i>IfcElectricFlowStorageDeviceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcElectricFlowStorageDevice</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming power used to charge the flow storage device.</li>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing power backed by the flow storage device.</li>
</ul>

"
3029;IfcOutlet;"<p>An outlet is a device installed at a point to receive one or more inserted plugs for electrical power or communications.</p>
<p>Power outlets are commonly connected within a junction box; data outlets may be directly connected to a wall. For power outlets sharing the same circuit within a junction box, the ports should indicate the logical wiring relationship to the enclosing junction box, even though they may be physically connected to a cable going to another outlet, switch, or fixture.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcOutlet</b> defines the occurrence of any outlet; common information about outlet types is handled by <i>IfcOutletType</i>. 
The <i>IfcOutletType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcOutletType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcOutletType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcOutlet</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 206 illustrates outlet type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcoutlet-Type.png""></td></tr><tr><td><p class=""figure"">Figure 206 &mdash; Outlet type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcOutletType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcOutletType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcOutlet</b> override the properties defined at <i>IfcOutletType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_OutletTypeCommon.xml"">Pset_OutletTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_OutletBaseQuantities.xml"">Qto_OutletBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcOutlet</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcOutletType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
<li><b>Conductor</b>: Material from which the conductors are constructed.</li>
<li><b>Surface</b>: Material from which the outer plate is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcOutlet</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the outlet occurrence is defined by <i>IfcOutletType</i>, then the port occurrences must reflect those defined at the <i>IfcOutletType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcOutlet</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcoutlettypeenum.htm"">DATAOUTLET</a>
<ul>
<li><b>Line#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A data line, connecting to a cable commonly originating from a port on a router.</li>
<li><b>Line#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A data line, connecting to a cable commonly originating from a port on a router.</li>
<li><b>Jack#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Jacks in order of layout, going to the right and then down, which may accept a cable.</li>
<li><b>Jack#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Jacks in order of layout, going to the right and then down, which may accept a cable.</li>
</ul>
</li>
<li><a href=""./ifcoutlettypeenum.htm"">POWEROUTLET</a>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The source of power, which may refer to a port on a junction box.</li>
<li><b>Jack#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Upper jack, accepting a plug from an appliance or fixture.</li>
<li><b>Jack#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Lower jack, accepting a plug from an appliance or fixture.</li>
</ul>
</li>
<li><a href=""./ifcoutlettypeenum.htm"">TELEPHONEOUTLET</a>
<ul>
<li><b>Line#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A telephone line, connecting to a cable originating from a telecommunications distribution board.</li>
<li><b>Line#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A telephone line, connecting to a cable originating from a telecommunications distribution board.</li>
<li><b>Jack#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Jacks in order of layout, going to the right and then down, which may accept a cable.</li>
<li><b>Jack#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Jacks in order of layout, going to the right and then down, which may accept a cable.</li>
</ul>
</li>
</ul>
<p>Figure 207 illustrates outlet port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcoutlet-Port.png""></td></tr><tr><td><p class=""figure"">Figure 207 &mdash; Outlet port use</p></td></tr></table>


"
3033;IfcLightFixture;"<p>A light fixture is a container that is designed for the purpose of housing one or more lamps and optionally devices that control, restrict or vary their emission.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcLightFixture</b> defines the occurrence of any light fixture; common information about light fixture types is handled by <i>IfcLightFixtureType</i>. 
The <i>IfcLightFixtureType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcLightFixtureType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcLightFixtureType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcLightFixture</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 204 illustrates light fixture type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifclightfixture-Type.png""></td></tr><tr><td><p class=""figure"">Figure 204 &mdash; Light fixture type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcLightFixtureType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcLightFixtureType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcLightFixture</b> override the properties defined at <i>IfcLightFixtureType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_LightFixtureTypeCommon.xml"">Pset_LightFixtureTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_LightFixtureTypeThermal.xml"">Pset_LightFixtureTypeThermal</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifclightfixturetypeenum.htm"">SECURITYLIGHTING</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_LightFixtureTypeSecurityLighting.xml"">Pset_LightFixtureTypeSecurityLighting</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_LightFixtureBaseQuantities.xml"">Qto_LightFixtureBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcLightFixture</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcLightFixtureType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcLightFixture</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcsharedbldgelements/lexical/ifccovering.htm"">IfcCovering</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Indicates a suspended ceiling anchoring the light fixture.</li>
<li><b><a href=""../../ifcproductextension/lexical/ifcopeningelement.htm"">IfcOpeningElement</a></b> (IfcRelFillsElements): Indicates embedding the light fixture in a building element such as a suspended ceiling.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcLightFixture</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the light fixture occurrence is defined by <i>IfcLightFixtureType</i>, then the port occurrences must reflect those defined at the <i>IfcLightFixtureType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcLightFixture</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The power supply line, typically a cable connected to a switch. </li>
<li><b>Socket#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
<li><b>Socket#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A lamp socket within the light fixture.</li>
</ul>
<p>Figure 205 illustrates light fixture port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifclightfixture-Port.png""></td></tr><tr><td><p class=""figure"">Figure 205 &mdash; Light fixture port use</p></td></tr></table>


"
3037;IfcLamp;"<p>A lamp is an artificial light source such as a light bulb or tube.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcLamp</b> defines the occurrence of any lamp; common information about lamp types is handled by <i>IfcLampType</i>. 
The <i>IfcLampType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcLampType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcLampType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcLamp</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 202 illustrates lamp type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifclamp-Type.png""></td></tr><tr><td><p class=""figure"">Figure 202 &mdash; Lamp type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcLampType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcLampType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcLamp</b> override the properties defined at <i>IfcLampType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_LampTypeCommon.xml"">Pset_LampTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_LampBaseQuantities.xml"">Qto_LampBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcLamp</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcLampType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Bulb</b>: Material from which the bulb is constructed such as glass.</li>
<li><b>Conductor</b>: Material from which the conductor is constructed.</li>
<li><b>Filament</b>: Material from which the filament is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcLamp</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the lamp occurrence is defined by <i>IfcLampType</i>, then the port occurrences must reflect those defined at the <i>IfcLampType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcLamp</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Socket</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">LIGHTING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The socket providing electricity.</li>
</ul>
<p>Figure 203 illustrates lamp port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifclamp-Port.png""></td></tr><tr><td><p class=""figure"">Figure 203 &mdash; Lamp port use</p></td></tr></table>


"
3041;IfcElectricAppliance;"<p>A communications appliance transmits and receives electronic or digital information as data or sound.</p>
<p>Communication appliances may be fixed in place or may be able to be moved from one space to another. Communication appliances require an electrical supply that may be supplied either by an electrical circuit or provided from a local battery source.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcElectricAppliance</b> defines the occurrence of any electric appliance; common information about electric appliance types is handled by <i>IfcElectricApplianceType</i>. 
The <i>IfcElectricApplianceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcElectricApplianceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcElectricApplianceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcElectricAppliance</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 196 illustrates electric appliance type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcelectricappliance-Type.png""></td></tr><tr><td><p class=""figure"">Figure 196 &mdash; Electric appliance type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcElectricApplianceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcElectricApplianceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcElectricAppliance</b> override the properties defined at <i>IfcElectricApplianceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricAppliancePHistory.xml"">Pset_ElectricAppliancePHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricApplianceTypeCommon.xml"">Pset_ElectricApplianceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">DISHWASHER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricApplianceTypeDishwasher.xml"">Pset_ElectricApplianceTypeDishwasher</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">ELECTRICCOOKER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricApplianceTypeElectricCooker.xml"">Pset_ElectricApplianceTypeElectricCooker</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ElectricApplianceBaseQuantities.xml"">Qto_ElectricApplianceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcElectricAppliance</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcElectricApplianceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcElectricAppliance</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the electric appliance occurrence is defined by <i>IfcElectricApplianceType</i>, then the port occurrences must reflect those defined at the <i>IfcElectricApplianceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcElectricAppliance</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcelectricappliancetypeenum.htm"">DISHWASHER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water used for washing dishes.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">ELECTRICCOOKER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">FREEZER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">FRIDGE_FREEZER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water used for icemaking and/or drinking water.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">HANDDRYER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">MICROWAVE</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">REFRIGERATOR</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">TUMBLEDRYER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Gas</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Gas source if applicable.</li>
<li><b>Exhaust</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Exhaust air.</li>
</ul>
</li>
<li><a href=""./ifcelectricappliancetypeenum.htm"">WASHINGMACHINE</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water used for washing.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water used for washing.</li>
<li><b>Drain</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage for water.</li>
</ul>
</li>
</ul>
<p>Figure 197 illustrates electric appliance port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcelectricappliance-Port.png""></td></tr><tr><td><p class=""figure"">Figure 197 &mdash; Electric appliance port use</p></td></tr></table>


"
3045;IfcAudioVisualAppliance;"<p>An audio-visual appliance is a device that displays, captures, transmits, or receives audio or video.</p>
<p>Audio-visual appliances may be fixed in place or may be able to be moved from one space to another. They may require an electrical supply that may be supplied either by an electrical circuit or provided from a local battery source. Audio-visual appliances may be connected to data circuits including specialist circuits for audio visual purposes only.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcAudioVisualAppliance</b> defines the occurrence of any audio visual appliance; common information about audio visual appliance types is handled by <i>IfcAudioVisualApplianceType</i>. 
The <i>IfcAudioVisualApplianceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcAudioVisualApplianceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcAudioVisualApplianceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcAudioVisualAppliance</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcAudioVisualApplianceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcAudioVisualApplianceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcAudioVisualAppliance</b> override the properties defined at <i>IfcAudioVisualApplianceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualAppliancePHistory.xml"">Pset_AudioVisualAppliancePHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeCommon.xml"">Pset_AudioVisualApplianceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">AMPLIFIER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeAmplifier.xml"">Pset_AudioVisualApplianceTypeAmplifier</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">CAMERA</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeCamera.xml"">Pset_AudioVisualApplianceTypeCamera</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">DISPLAY</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeDisplay.xml"">Pset_AudioVisualApplianceTypeDisplay</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">PLAYER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypePlayer.xml"">Pset_AudioVisualApplianceTypePlayer</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">PROJECTOR</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeProjector.xml"">Pset_AudioVisualApplianceTypeProjector</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">RECEIVER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeReceiver.xml"">Pset_AudioVisualApplianceTypeReceiver</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">SPEAKER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeSpeaker.xml"">Pset_AudioVisualApplianceTypeSpeaker</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">TUNER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_AudioVisualApplianceTypeTuner.xml"">Pset_AudioVisualApplianceTypeTuner</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_AudioVisualApplianceBaseQuantities.xml"">Qto_AudioVisualApplianceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcAudioVisualAppliance</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcAudioVisualApplianceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcAudioVisualAppliance</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcAudioVisualAppliance</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li>May contain IfcAudioVisualAppliance components.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcAudioVisualAppliance</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the audio visual appliance occurrence is defined by <i>IfcAudioVisualApplianceType</i>, then the port occurrences must reflect those defined at the <i>IfcAudioVisualApplianceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcAudioVisualAppliance</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">AMPLIFIER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio.</li>
<li><b>Speakers</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTROACCOUSTIC</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Audio speaker(s), which may be aggregated for separate speaker channels.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">CAMERA</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Network</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Network access.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Captured video.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">DISPLAY</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Input#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">MICROPHONE</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Captured audio.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">PLAYER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Rendered media content.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">PROJECTOR</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Input audio/video source.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">RECEIVER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Network</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Network access.</li>
<li><b>Input#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Output#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Speakers#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTROACCOUSTIC</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Audio speaker(s), which may be aggregated for separate speaker channels.</li>
<li><b>Speakers#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTROACCOUSTIC</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Audio speaker(s), which may be aggregated for separate speaker channels.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">SPEAKER</a>
<ul>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTROACCOUSTIC</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Amplified audio input.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">SWITCHER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Network</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Network access.</li>
<li><b>Input#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Input#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Input audio/video source.</li>
<li><b>Output#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
<li><b>Output#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Output audio/video zone.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">TELEPHONE</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Phone</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TELEPHONE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Telecommunications network.</li>
</ul>
</li>
<li><a href=""./ifcaudiovisualappliancetypeenum.htm"">TUNER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives control signal.</li>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TV</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives modulated data feed such as satellite, cable, or over-the-air.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Rendered media content.</li>
</ul>
</li>
</ul>

"
3049;IfcCommunicationsAppliance;"<p>A communications appliance transmits and receives electronic or digital information as data or sound.</p>
<p>Communication appliances may be fixed in place or may be able to be moved from one space to another. Communication appliances require an electrical supply that may be supplied either by an electrical circuit or provided from a local battery source.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCommunicationsAppliance</b> defines the occurrence of any communications appliance; common information about communications appliance types is handled by <i>IfcCommunicationsApplianceType</i>. 
The <i>IfcCommunicationsApplianceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCommunicationsApplianceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCommunicationsApplianceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCommunicationsAppliance</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCommunicationsApplianceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCommunicationsApplianceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCommunicationsAppliance</b> override the properties defined at <i>IfcCommunicationsApplianceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CommunicationsAppliancePHistory.xml"">Pset_CommunicationsAppliancePHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_CommunicationsApplianceTypeCommon.xml"">Pset_CommunicationsApplianceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_CommunicationsApplianceBaseQuantities.xml"">Qto_CommunicationsApplianceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCommunicationsAppliance</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCommunicationsApplianceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcCommunicationsAppliance</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcCommunicationsAppliance</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">COMPUTER</a>
<ul>
<li>May contain <i>IfcAudioVisualAppliance</i> components. Computers may be aggregated into audio-visual components such as displays, cameras, speakers, or microphones.</li>
</ul>
</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcCommunicationsAppliance</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcsharedfacilitieselements/lexical/ifcsystemfurnitureelement.htm"">IfcSystemFurnitureElement</a></b> (<a href=""../../ifcproductextension/lexical/ifcrelconnectselements.htm"">IfcRelConnectsElements</a>): Servers and other networking equipment may be installed in racks.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCommunicationsAppliance</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the communications appliance occurrence is defined by <i>IfcCommunicationsApplianceType</i>, then the port occurrences must reflect those defined at the <i>IfcCommunicationsApplianceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCommunicationsAppliance</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">ANTENNA</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Radio</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Electromagnetic waves.</li>
<li><b>Signal</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The modulated analog signal in a circuit, such as a cable connected to a modem. </li>
</ul>
</li>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">COMPUTER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Network</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A network connection, may be wired or wireless (implicit antenna), such as a cable connected from a data outlet jack or from a router communications appliance. While communication is bidirectional, the router-end is considered to be the source.</li>
<li><b>Device</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A device connection such as USB or serial, which may connect to equipment such as a building automation controller.</li>
<li><b>Display</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AUDIOVISUAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Audio/video output, such as a cable connected to a display, which may be aggregated into separate channels.</li>
</ul>
</li>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">FAX</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Telephone</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TELEPHONE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Telephone connection.</li>
</ul>
</li>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">MODEM</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Signal</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Modulated analog signal, typically a cable connecting from a communications junction box or an antenna.</li>
<li><b>Internet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Internet data network.</li>
<li><b>Television</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TV</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Television modulated signal.</li>
<li><b>Telephone</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">TELEPHONE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Telephone communications.</li>
</ul>
</li>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">PRINTER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Network</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): A network connection, may be wired or wireless (implicit antenna), such as a cable connected from a data outlet jack or from a router communications appliance. While communication is bidirectional, the router-end is considered to be the source.</li>
</ul>
</li>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">REPEATER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Input</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The receiving signal.</li>
<li><b>Output</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">SIGNAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The transmittes signal.</li>
</ul>
</li>
<li><a href=""./ifccommunicationsappliancetypeenum.htm"">ROUTER</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Uplink</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Uplink from another network, such as a cable connected to another router or the Internet.</li>
<li><b>Link#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
<li><b>Link#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DATA</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A network link to a routed device such as a cable connecting to a computer.</li>
</ul>
</li>
</ul>

"
3053;IfcSwitchingDevice;"<p>A switch is used in a cable distribution system (electrical circuit) to control or modulate the flow of electricity.</p>
<p>Switches include those used for electrical power, communications, audio-visual, or other distribution system types as determined by the available ports.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcSwitchingDevice</b> defines the occurrence of any switching device; common information about switching device types is handled by <i>IfcSwitchingDeviceType</i>. 
The <i>IfcSwitchingDeviceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcSwitchingDeviceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcSwitchingDeviceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcSwitchingDevice</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 208 illustrates switching device type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcswitchingdevice-Type.png""></td></tr><tr><td><p class=""figure"">Figure 208 &mdash; Switching device type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcSwitchingDeviceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcSwitchingDeviceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcSwitchingDevice</b> override the properties defined at <i>IfcSwitchingDeviceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeCommon.xml"">Pset_SwitchingDeviceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypePHistory.xml"">Pset_SwitchingDeviceTypePHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">CONTACTOR</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeContactor.xml"">Pset_SwitchingDeviceTypeContactor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">DIMMERSWITCH</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeDimmerSwitch.xml"">Pset_SwitchingDeviceTypeDimmerSwitch</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">EMERGENCYSTOP</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeEmergencyStop.xml"">Pset_SwitchingDeviceTypeEmergencyStop</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">KEYPAD</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeKeypad.xml"">Pset_SwitchingDeviceTypeKeypad</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">MOMENTARYSWITCH</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeMomentarySwitch.xml"">Pset_SwitchingDeviceTypeMomentarySwitch</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">SELECTORSWITCH</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeSelectorSwitch.xml"">Pset_SwitchingDeviceTypeSelectorSwitch</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">STARTER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeStarter.xml"">Pset_SwitchingDeviceTypeStarter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">SWITCHDISCONNECTOR</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeSwitchDisconnector.xml"">Pset_SwitchingDeviceTypeSwitchDisconnector</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcswitchingdevicetypeenum.htm"">TOGGLESWITCH</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SwitchingDeviceTypeToggleSwitch.xml"">Pset_SwitchingDeviceTypeToggleSwitch</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_SwitchingDeviceBaseQuantities.xml"">Qto_SwitchingDeviceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcSwitchingDevice</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcSwitchingDeviceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
<li><b>Conductor</b>: Material from which the conductors are constructed.</li>
<li><b>Surface</b>: Material from which the switch surface is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcSwitchingDevice</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the switching device occurrence is defined by <i>IfcSwitchingDeviceType</i>, then the port occurrences must reflect those defined at the <i>IfcSwitchingDeviceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcSwitchingDevice</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The supply line.</li>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The load controlled by the switch.</li>
</ul>
<p>Figure 209 illustrates switching device port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcswitchingdevice-Port.png""></td></tr><tr><td><p class=""figure"">Figure 209 &mdash; Switching device port use</p></td></tr></table>


"
3057;IfcProtectiveDevice;"<p>A protective device breaks an electrical circuit when a stated electric current that passes through it is exceeded.</p>
<p>A protective device provides protection against electrical current only (not as a general protective device). It may be used to represent the complete set of elements including both the tripping unit and the breaking unit that provide the protection. This may be particularly useful at earlier stages of design where the approach to breaking the electrical supply may be determined but the method of tripping may not. Alternatively, this entity may be used to specifically represent the breaking unit alone (in which case the tripping unit will also be specifically identified). This entity is specific to dedicated protective devices and excludes electrical outlets that may have circuit protection.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcProtectiveDevice</b> defines the occurrence of any protective device; common information about protective device types is handled by <i>IfcProtectiveDeviceType</i>. 
The <i>IfcProtectiveDeviceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcProtectiveDeviceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcProtectiveDeviceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcProtectiveDevice</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcProtectiveDeviceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcProtectiveDeviceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcProtectiveDevice</b> override the properties defined at <i>IfcProtectiveDeviceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceBreakerUnitI2TCurve.xml"">Pset_ProtectiveDeviceBreakerUnitI2TCurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceBreakerUnitI2TFuseCurve.xml"">Pset_ProtectiveDeviceBreakerUnitI2TFuseCurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceBreakerUnitIPICurve.xml"">Pset_ProtectiveDeviceBreakerUnitIPICurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceBreakerUnitTypeMotorProtection.xml"">Pset_ProtectiveDeviceBreakerUnitTypeMotorProtection</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingCurve.xml"">Pset_ProtectiveDeviceTrippingCurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeCommon.xml"">Pset_ProtectiveDeviceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">CIRCUITBREAKER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceBreakerUnitTypeMCB.xml"">Pset_ProtectiveDeviceBreakerUnitTypeMCB</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeCircuitBreaker.xml"">Pset_ProtectiveDeviceTypeCircuitBreaker</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">EARTHLEAKAGECIRCUITBREAKER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeEarthLeakageCircuitBreaker.xml"">Pset_ProtectiveDeviceTypeEarthLeakageCircuitBreaker</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">FUSEDISCONNECTOR</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeFuseDisconnector.xml"">Pset_ProtectiveDeviceTypeFuseDisconnector</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">RESIDUALCURRENTCIRCUITBREAKER</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeResidualCurrentCircuitBreaker.xml"">Pset_ProtectiveDeviceTypeResidualCurrentCircuitBreaker</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">RESIDUALCURRENTSWITCH</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeResidualCurrentSwitch.xml"">Pset_ProtectiveDeviceTypeResidualCurrentSwitch</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">VARISTOR</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTypeVaristor.xml"">Pset_ProtectiveDeviceTypeVaristor</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ProtectiveDeviceBaseQuantities.xml"">Qto_ProtectiveDeviceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcProtectiveDevice</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcProtectiveDeviceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcProtectiveDevice</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the protective device occurrence is defined by <i>IfcProtectiveDeviceType</i>, then the port occurrences must reflect those defined at the <i>IfcProtectiveDeviceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcProtectiveDevice</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcprotectivedevicetypeenum.htm"">CIRCUITBREAKER</a>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The supply line, typically connected from a slot in a distribution board.</li>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The load protected by this device, typically a cable connected to a device or the first junction box of a circuit.</li>
</ul>
</li>
</ul>

"
3061;IfcElectricDistributionBoard;"<p>A distribution board is a flow controller in which instances of electrical devices are brought together at a single place for a particular purpose.</p>
<p>A distribution provides a housing for connected electrical distribution elements so that they can be viewed, operated or acted upon from a single place. Each connected item may have its own geometric representation and location.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcElectricDistributionBoard</b> defines the occurrence of any electric distribution board; common information about electric distribution board types is handled by <i>IfcElectricDistributionBoardType</i>. 
The <i>IfcElectricDistributionBoardType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcElectricDistributionBoardType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcElectricDistributionBoardType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcElectricDistributionBoard</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 198 illustrates electric distribution board type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcelectricdistributionboard-Type.png""></td></tr><tr><td><p class=""figure"">Figure 198 &mdash; Electric distribution board type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcElectricDistributionBoardType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcElectricDistributionBoardType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcElectricDistributionBoard</b> override the properties defined at <i>IfcElectricDistributionBoardType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricDistributionBoardTypeCommon.xml"">Pset_ElectricDistributionBoardTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ElectricDistributionBoardBaseQuantities.xml"">Qto_ElectricDistributionBoardBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcElectricDistributionBoard</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcElectricDistributionBoardType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcElectricDistributionBoard</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the electric distribution board occurrence is defined by <i>IfcElectricDistributionBoardType</i>, then the port occurrences must reflect those defined at the <i>IfcElectricDistributionBoardType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcElectricDistributionBoard</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcelectricdistributionboardtypeenum.htm"">CONSUMERUNIT</a>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming power, such as a cable connecting from the electrical utility or another distribution board.</li>
<li><b>Ground</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EARTHING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Grounding connection, such as a cable connecting to a cable fitting connected to a cold water pipe segment coming from the ground.</li>
<li><b>Circuit#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#3</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#4</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#5</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#6</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#7</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
<li><b>Circuit#8</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): A downstream circuit, typically a circuit breaker protective device.</li>
</ul>
</li>
</ul>
<p>Figure 199 illustrates electric distribution board port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcelectricdistributionboard-Port.png""></td></tr><tr><td><p class=""figure"">Figure 199 &mdash; Electric distribution board port use</p></td></tr></table>


"
3065;IfcElectricTimeControl;"<p>An electric time control is a device that applies control to the provision or flow of electrical energy over time.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcElectricTimeControl</b> defines the occurrence of any electric time control; common information about electric time control types is handled by <i>IfcElectricTimeControlType</i>. 
The <i>IfcElectricTimeControlType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcElectricTimeControlType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcElectricTimeControlType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcElectricTimeControl</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcElectricTimeControlType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcElectricTimeControlType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcElectricTimeControl</b> override the properties defined at <i>IfcElectricTimeControlType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricTimeControlTypeCommon.xml"">Pset_ElectricTimeControlTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ElectricTimeControlBaseQuantities.xml"">Qto_ElectricTimeControlBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcElectricTimeControl</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcElectricTimeControlType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcElectricTimeControl</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the electric time control occurrence is defined by <i>IfcElectricTimeControlType</i>, then the port occurrences must reflect those defined at the <i>IfcElectricTimeControlType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcElectricTimeControl</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Transmits electrical power according to time.</li>
</ul>

"
3069;IfcTransformer;"<p>A transformer is an inductive stationary device that transfers electrical energy from one circuit to another.</p>
<p><i>IfcTransformer</i> is used to transform electric power; conversion of electric signals for other purposes is handled at other entities: <i>IfcController</i> converts arbitrary signals, <i>IfcAudioVisualAppliance</i> converts signals for audio or video streams, and <i>IfcCommunicationsAppliance</i> converts signals for data or other communications usage.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcTransformer</b> defines the occurrence of any transformer; common information about transformer types is handled by <i>IfcTransformerType</i>. 
The <i>IfcTransformerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcTransformerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcTransformerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcTransformer</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcTransformerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcTransformerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcTransformer</b> override the properties defined at <i>IfcTransformerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_TransformerTypeCommon.xml"">Pset_TransformerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_TransformerBaseQuantities.xml"">Qto_TransformerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcTransformer</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcTransformerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcTransformer</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the transformer occurrence is defined by <i>IfcTransformerType</i>, then the port occurrences must reflect those defined at the <i>IfcTransformerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcTransformer</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Line to be transformed.</li>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Transformed load.</li>
</ul>

"
3081;IfcElectricGenerator;"<p>An electric generator is an engine that is a machine for converting mechanical energy into electrical energy.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcElectricGenerator</b> defines the occurrence of any electric generator; common information about electric generator types is handled by <i>IfcElectricGeneratorType</i>. 
The <i>IfcElectricGeneratorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcElectricGeneratorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcElectricGeneratorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcElectricGenerator</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcElectricGeneratorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcElectricGeneratorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcElectricGenerator</b> override the properties defined at <i>IfcElectricGeneratorType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricGeneratorTypeCommon.xml"">Pset_ElectricGeneratorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ElectricGeneratorBaseQuantities.xml"">Qto_ElectricGeneratorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcElectricGenerator</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcElectricGeneratorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcElectricGenerator</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcElectricGenerator</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li><a href=""./ifcelectricgeneratortypeenum.htm"">ENGINEGENERATOR</a>
<ul>
<li>May contain <i>IfcEngine</i> components. Engine-Generator sets may optionally include an engine to indicate specific detail.</li>
</ul>
</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcElectricGenerator</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the electric generator occurrence is defined by <i>IfcElectricGeneratorType</i>, then the port occurrences must reflect those defined at the <i>IfcElectricGeneratorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcElectricGenerator</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Load</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing power from generator.</li>
</ul>

"
3091;IfcElectricMotor;"<p>An electric motor is an engine that is a machine for converting electrical energy into mechanical energy.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcElectricMotor</b> defines the occurrence of any electric motor; common information about electric motor types is handled by <i>IfcElectricMotorType</i>. 
The <i>IfcElectricMotorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcElectricMotorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcElectricMotorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcElectricMotor</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcElectricMotorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcElectricMotorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcElectricMotor</b> override the properties defined at <i>IfcElectricMotorType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ElectricMotorTypeCommon.xml"">Pset_ElectricMotorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ElectricMotorBaseQuantities.xml"">Qto_ElectricMotorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcElectricMotor</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcElectricMotorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcElectricMotor</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the electric motor occurrence is defined by <i>IfcElectricMotorType</i>, then the port occurrences must reflect those defined at the <i>IfcElectricMotorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcElectricMotor</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Drive</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Motor connection to a driven device.</li>
</ul>

"
3103;IfcMotorConnection;"<p>A motor connection provides the means for connecting a motor as the driving device to the driven device.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcMotorConnection</b> defines the occurrence of any motor connection; common information about motor connection types is handled by <i>IfcMotorConnectionType</i>. 
The <i>IfcMotorConnectionType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcMotorConnectionType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcMotorConnectionType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcMotorConnection</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcMotorConnectionType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcMotorConnectionType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcMotorConnection</b> override the properties defined at <i>IfcMotorConnectionType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_MotorConnectionTypeCommon.xml"">Pset_MotorConnectionTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_MotorConnectionBaseQuantities.xml"">Qto_MotorConnectionBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcMotorConnection</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcMotorConnectionType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcMotorConnection</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the motor connection occurrence is defined by <i>IfcMotorConnectionType</i>, then the port occurrences must reflect those defined at the <i>IfcMotorConnectionType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcMotorConnection</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Motor</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Connection from the motor.</li>
<li><b>Drive</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Connection to the driven device.</li>
</ul>

"
3113;IfcSolarDevice;"<p>A solar device converts solar radiation into other energy such as electric current or thermal energy.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcSolarDevice</b> defines the occurrence of any solar device; common information about solar device types is handled by <i>IfcSolarDeviceType</i>. 
The <i>IfcSolarDeviceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcSolarDeviceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcSolarDeviceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcSolarDevice</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcSolarDeviceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcSolarDeviceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcSolarDevice</b> override the properties defined at <i>IfcSolarDeviceType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_SolarDeviceTypeCommon.xml"">Pset_SolarDeviceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_SolarDeviceBaseQuantities.xml"">Qto_SolarDeviceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcSolarDevice</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcSolarDeviceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Casing</b>: Material from which the casing is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcSolarDevice</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the solar device occurrence is defined by <i>IfcSolarDeviceType</i>, then the port occurrences must reflect those defined at the <i>IfcSolarDeviceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcSolarDevice</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcsolardevicetypeenum.htm"">SOLARCOLLECTOR</a>
<ul>
<li><b>Heating</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Incoming water.</li>
<li><b>Heating</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Outgoing heated water.</li>
</ul>
</li>
<li><a href=""./ifcsolardevicetypeenum.htm"">SOLARPANEL</a>
<ul>
<li><b>PowerGeneration</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">POWERGENERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Converted electrical power.</li>
</ul>
</li>
</ul>

"
3122;IfcProtectiveDeviceTrippingUnit;"<b><u>Entity Definition</u></b> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcProtectiveDeviceTrippingUnit</b> defines the occurrence of any protective device tripping unit; common information about protective device tripping unit types is handled by <i>IfcProtectiveDeviceTrippingUnitType</i>. 
The <i>IfcProtectiveDeviceTrippingUnitType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcProtectiveDeviceTrippingUnitType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcProtectiveDeviceTrippingUnitType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcProtectiveDeviceTrippingUnit</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcProtectiveDeviceTrippingUnitType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcProtectiveDeviceTrippingUnitType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcProtectiveDeviceTrippingUnit</b> override the properties defined at <i>IfcProtectiveDeviceTrippingUnitType</i>. 
Refer to the documentation at the supertype <i>IfcDistributionControlElement</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingFunctionGCurve.xml"">Pset_ProtectiveDeviceTrippingFunctionGCurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingFunctionICurve.xml"">Pset_ProtectiveDeviceTrippingFunctionICurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingFunctionLCurve.xml"">Pset_ProtectiveDeviceTrippingFunctionLCurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingFunctionSCurve.xml"">Pset_ProtectiveDeviceTrippingFunctionSCurve</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitCurrentAdjustment.xml"">Pset_ProtectiveDeviceTrippingUnitCurrentAdjustment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitTimeAdjustment.xml"">Pset_ProtectiveDeviceTrippingUnitTimeAdjustment</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitTypeCommon.xml"">Pset_ProtectiveDeviceTrippingUnitTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetrippingunittypeenum.htm"">ELECTROMAGNETIC</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitTypeElectroMagnetic.xml"">Pset_ProtectiveDeviceTrippingUnitTypeElectroMagnetic</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetrippingunittypeenum.htm"">ELECTRONIC</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitTypeElectronic.xml"">Pset_ProtectiveDeviceTrippingUnitTypeElectronic</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetrippingunittypeenum.htm"">RESIDUALCURRENT</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitTypeResidualCurrent.xml"">Pset_ProtectiveDeviceTrippingUnitTypeResidualCurrent</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcprotectivedevicetrippingunittypeenum.htm"">THERMAL</a>
<ul>
<li><a href=""../../psd/ifcelectricaldomain/Pset_ProtectiveDeviceTrippingUnitTypeThermal.xml"">Pset_ProtectiveDeviceTrippingUnitTypeThermal</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcelectricaldomain/Qto_ProtectiveDeviceTrippingUnitBaseQuantities.xml"">Qto_ProtectiveDeviceTrippingUnitBaseQuantities</a></li>
</ul>

"
3126;IfcElectricGeneratorType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcElectricGeneratorType</b> defines commonly shared information for occurrences of electric generators.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a electric generator specification (i.e. the specific product information, that is common to all occurrences of that product type).  Electric Generator types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcElectricGeneratorType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcelectricgenerator.htm"">IfcElectricGenerator</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricGeneratorTypeCommon.xml"" target=""SOURCE"">Pset_ElectricGeneratorTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcElectricGeneratorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcElectricGeneratorType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcElectricGeneratorType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifcelectricaldomain/lexical/ifcelectricgeneratortypeenum.htm"">ENGINEGENERATOR</a>: May contain <a href=""../../ifchvacdomain/lexical/ifcengine.htm"">IfcEngine</a> components.  Engine-Generator sets may optionally include an engine to indicate specific detail.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcElectricGeneratorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcelectricgenerator.htm"">IfcElectricGenerator</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3129;IfcTransformerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcTransformerType</b> defines commonly shared information for occurrences of transformers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a transformer specification (i.e. the specific product information, that is common to all occurrences of that product type).  Transformer types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcTransformerType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifctransformer.htm"">IfcTransformer</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_TransformerTypeCommon.xml"" target=""SOURCE"">Pset_TransformerTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcTransformerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcTransformerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifctransformer.htm"">IfcTransformer</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3132;IfcElectricMotorType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcElectricMotorType</b> defines commonly shared information for occurrences of electric motors.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a electric motor specification (i.e. the specific product information, that is common to all occurrences of that product type).  Electric Motor types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcElectricMotorType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcelectricmotor.htm"">IfcElectricMotor</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricalDeviceCommon.xml"" target=""SOURCE"">Pset_ElectricalDeviceCommon</a></li> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_ElectricMotorTypeCommon.xml"" target=""SOURCE"">Pset_ElectricMotorTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcElectricMotorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcElectricMotorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcelectricmotor.htm"">IfcElectricMotor</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3135;IfcSolarDeviceType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcSolarDeviceType</b> defines commonly shared information for occurrences of solar devices.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a solar device specification (i.e. the specific product information, that is common to all occurrences of that product type).  Solar Device types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcSolarDeviceType</b> are represented by instances of <a href=""../../ifcelectricaldomain/lexical/ifcsolardevice.htm"">IfcSolarDevice</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcElectricalDomain/Pset_SolarDeviceTypeCommon.xml"" target=""SOURCE"">Pset_SolarDeviceTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSolarDeviceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcSolarDeviceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcelectricaldomain/lexical/ifcsolardevice.htm"">IfcSolarDevice</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3139;IfcAirToAirHeatRecoveryType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcAirToAirHeatRecoveryType</b> defines commonly shared information for occurrences of air-to-air heat recovery devices.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a air-to-air heat recovery device specification (i.e. the specific product information, that is common to all occurrences of that product type).  Air-To-Air Heat Recovery Device types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcAirToAirHeatRecoveryType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcairtoairheatrecovery.htm"">IfcAirToAirHeatRecovery</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_AirToAirHeatRecoveryTypeCommon.xml"" target=""SOURCE"">Pset_AirToAirHeatRecoveryTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcAirToAirHeatRecoveryType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Media'</b>: The primary media material used for heat transfer.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcAirToAirHeatRecoveryType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcairtoairheatrecovery.htm"">IfcAirToAirHeatRecovery</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3154;IfcBoilerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcBoilerType</b> defines commonly shared information for occurrences of boilers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a boiler specification (i.e. the specific product information, that is common to all occurrences of that product type).  Boiler types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcBoilerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcboiler.htm"">IfcBoiler</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_BoilerTypeCommon.xml"" target=""SOURCE"">Pset_BoilerTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_BoilerTypeSteam.xml"" target=""SOURCE"">Pset_BoilerTypeSteam</a> (<a href=""../../ifchvacdomain/lexical/ifcboilertypeenum.htm"">STEAM</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcBoilerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcBoilerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcboiler.htm"">IfcBoiler</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3162;IfcBurnerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcBurnerType</b> defines commonly shared information for occurrences of burners.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a burner specification (i.e. the specific product information, that is common to all occurrences of that product type).  Burner types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcBurnerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcburner.htm"">IfcBurner</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_BurnerTypeCommon.xml"" target=""SOURCE"">Pset_BurnerTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcBurnerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Fuel'</b>: Material designed to be burned.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcBurnerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcburner.htm"">IfcBurner</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3168;IfcChillerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcChillerType</b> defines commonly shared information for occurrences of chillers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a chiller specification (i.e. the specific product information, that is common to all occurrences of that product type).  Chiller types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcChillerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcchiller.htm"">IfcChiller</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ChillerTypeCommon.xml"" target=""SOURCE"">Pset_ChillerTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcChillerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Refrigerant'</b>: Refrigerant material.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcChillerType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcChillerType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcproductextension/lexical/ifcdistributionelement.htm"">IfcDistributionElement</a> components.  Chillers may aggregate distribution flow elements forming a refrigeration cycle (compressor, condenser, valve, evaporator), as well as control elements.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcChillerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcchiller.htm"">IfcChiller</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3177;IfcCoilType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcCoilType</b> defines commonly shared information for occurrences of coils.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a coil specification (i.e. the specific product information, that is common to all occurrences of that product type).  Coil types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCoilType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifccoil.htm"">IfcCoil</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CoilTypeCommon.xml"" target=""SOURCE"">Pset_CoilTypeCommon</a></li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CoilTypeHydronic.xml"" target=""SOURCE"">Pset_CoilTypeHydronic</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCoilType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCoilType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifccoil.htm"">IfcCoil</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3190;IfcCondenserType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcCondenserType</b> defines commonly shared information for occurrences of condensers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a condenser specification (i.e. the specific product information, that is common to all occurrences of that product type).  Condenser types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCondenserType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifccondenser.htm"">IfcCondenser</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CondenserTypeCommon.xml"" target=""SOURCE"">Pset_CondenserTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCondenserType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Refrigerant'</b>: Refrigerant material.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCondenserType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifccondenser.htm"">IfcCondenser</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3203;IfcCooledBeamType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcCooledBeamType</b> defines commonly shared information for occurrences of cooled beams.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a cooled beam specification (i.e. the specific product information, that is common to all occurrences of that product type).  Cooled Beam types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCooledBeamType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifccooledbeam.htm"">IfcCooledBeam</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CooledBeamTypeCommon.xml"" target=""SOURCE"">Pset_CooledBeamTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CooledBeamTypeActive.xml"" target=""SOURCE"">Pset_CooledBeamTypeActive</a> (<a href=""../../ifchvacdomain/lexical/ifccooledbeamtypeenum.htm"">ACTIVE</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCooledBeamType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCooledBeamType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifccooledbeam.htm"">IfcCooledBeam</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3211;IfcCoolingTowerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcCoolingTowerType</b> defines commonly shared information for occurrences of cooling towers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a cooling tower specification (i.e. the specific product information, that is common to all occurrences of that product type).  Cooling Tower types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCoolingTowerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifccoolingtower.htm"">IfcCoolingTower</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CoolingTowerTypeCommon.xml"" target=""SOURCE"">Pset_CoolingTowerTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCoolingTowerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Fill'</b>: Fill material.</li> 
</ul> 
 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcCoolingTowerType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcCoolingTowerType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><a href=""../../ifchvacdomain/lexical/ifccoolingtowertypeenum.htm"">MECHANICALFORCEDDRAFT</a>: May contain <a href=""../../ifchvacdomain/lexical/ifcfan.htm"">IfcFan</a> components.  Forces air into the cooling tower.</li> 
<li><a href=""../../ifchvacdomain/lexical/ifccoolingtowertypeenum.htm"">MECHANICALINDUCEDDRAFT</a>: May contain <a href=""../../ifchvacdomain/lexical/ifcfan.htm"">IfcFan</a> components.  Induces air out of the cooling tower.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCoolingTowerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifccoolingtower.htm"">IfcCoolingTower</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3220;IfcEvaporativeCoolerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcEvaporativeCoolerType</b> defines commonly shared information for occurrences of evaporative coolers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a evaporative cooler specification (i.e. the specific product information, that is common to all occurrences of that product type).  Evaporative Cooler types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcEvaporativeCoolerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcevaporativecooler.htm"">IfcEvaporativeCooler</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_EvaporativeCoolerTypeCommon.xml"" target=""SOURCE"">Pset_EvaporativeCoolerTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcEvaporativeCoolerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Media'</b>: Heat exchanger media material.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcEvaporativeCoolerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcevaporativecooler.htm"">IfcEvaporativeCooler</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3235;IfcEvaporatorType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcEvaporatorType</b> defines commonly shared information for occurrences of evaporators.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a evaporator specification (i.e. the specific product information, that is common to all occurrences of that product type).  Evaporator types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcEvaporatorType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcevaporator.htm"">IfcEvaporator</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_EvaporatorTypeCommon.xml"" target=""SOURCE"">Pset_EvaporatorTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcEvaporatorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Refrigerant'</b>: Refrigerant material.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcEvaporatorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcevaporator.htm"">IfcEvaporator</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3247;IfcHeatExchangerType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcHeatExchangerType</b> defines commonly shared information for occurrences of heat exchangers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a heat exchanger specification (i.e. the specific product information, that is common to all occurrences of that product type).  Heat Exchanger types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcHeatExchangerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcheatexchanger.htm"">IfcHeatExchanger</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_HeatExchangerTypeCommon.xml"" target=""SOURCE"">Pset_HeatExchangerTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_HeatExchangerTypePlate.xml"" target=""SOURCE"">Pset_HeatExchangerTypePlate</a> (<a href=""../../ifchvacdomain/lexical/ifcheatexchangertypeenum.htm"">PLATE</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcHeatExchangerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Shell'</b>: Material used to construct the shell of the heat exchanger.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcHeatExchangerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcheatexchanger.htm"">IfcHeatExchanger</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3255;IfcHumidifierType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcHumidifierType</b> defines commonly shared information for occurrences of humidifiers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a humidifier specification (i.e. the specific product information, that is common to all occurrences of that product type).  Humidifier types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcHumidifierType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifchumidifier.htm"">IfcHumidifier</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_HumidifierTypeCommon.xml"" target=""SOURCE"">Pset_HumidifierTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcHumidifierType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcHumidifierType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifchumidifier.htm"">IfcHumidifier</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3274;IfcTubeBundleType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcTubeBundleType</b> defines commonly shared information for occurrences of tube bundles.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a tube bundle specification (i.e. the specific product information, that is common to all occurrences of that product type).  Tube Bundle types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcTubeBundleType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifctubebundle.htm"">IfcTubeBundle</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TubeBundleTypeCommon.xml"" target=""SOURCE"">Pset_TubeBundleTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TubeBundleTypeFinned.xml"" target=""SOURCE"">Pset_TubeBundleTypeFinned</a> (<a href=""../../ifchvacdomain/lexical/ifctubebundletypeenum.htm"">FINNED</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcTubeBundleType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: Material used for construction of the tubes.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcTubeBundleType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifctubebundle.htm"">IfcTubeBundle</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3281;IfcUnitaryEquipmentType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcUnitaryEquipmentType</b> defines commonly shared information for occurrences of unitary equipments.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a unitary equipment specification (i.e. the specific product information, that is common to all occurrences of that product type).  Unitary Equipment types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcUnitaryEquipmentType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcunitaryequipment.htm"">IfcUnitaryEquipment</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_UnitaryEquipmentTypeCommon.xml"" target=""SOURCE"">Pset_UnitaryEquipmentTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcUnitaryEquipmentType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.  </p> 
<p><b><u>Composition Use Definition</u></b></p> 
<p>The <b>IfcUnitaryEquipmentType</b> may be aggregated into components using <a href=""../../ifckernel/lexical/ifcrelaggregates.htm"">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcUnitaryEquipmentType</b> and <i>RelatedObjects</i> contains one or more components.  Components are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Aggregation use is defined for the following predefined types:
<ul> 
<li><b>(All Types)</b>: May contain <a href=""../../ifcproductextension/lexical/ifcdistributionelement.htm"">IfcDistributionElement</a> components.  Unitary equipment (air handlers in particular) may elaborate contained elements such as dampers, fans, coils, sensors, actuators, and controllers.  Such breakdown provides access to component information and tracking of performance history for embedded elements.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcUnitaryEquipmentType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcunitaryequipment.htm"">IfcUnitaryEquipment</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3292;IfcEngineType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcEngineType</b> defines commonly shared information for occurrences of engines.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a engine specification (i.e. the specific product information, that is common to all occurrences of that product type).  Engine types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcEngineType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcengine.htm"">IfcEngine</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_EngineTypeCommon.xml"" target=""SOURCE"">Pset_EngineTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcEngineType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcEngineType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcengine.htm"">IfcEngine</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3300;IfcFanType;"<EPM-HTML> 
 
<p>The flow moving device type <b>IfcFanType</b> defines commonly shared information for occurrences of fans.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a fan specification (i.e. the specific product information, that is common to all occurrences of that product type).  Fan types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcFanType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcfan.htm"">IfcFan</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowmovingdevicetype.htm"">IfcFlowMovingDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FanTypeCommon.xml"" target=""SOURCE"">Pset_FanTypeCommon</a></li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FanTypeSmokeControl.xml"" target=""SOURCE"">Pset_FanTypeSmokeControl</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFanType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Housing'</b>: The material used to construct the fan housing.</li> 
<li><b>'Wheel'</b>: The material used to construct the fan wheel.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcFanType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcfan.htm"">IfcFan</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3313;IfcCompressorType;"<EPM-HTML> 
 
<p>The flow moving device type <b>IfcCompressorType</b> defines commonly shared information for occurrences of compressors.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a compressor specification (i.e. the specific product information, that is common to all occurrences of that product type).  Compressor types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcCompressorType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifccompressor.htm"">IfcCompressor</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowmovingdevicetype.htm"">IfcFlowMovingDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_CompressorTypeCommon.xml"" target=""SOURCE"">Pset_CompressorTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcCompressorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
<li><b>'Refrigerant'</b>: Refrigerant material.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcCompressorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifccompressor.htm"">IfcCompressor</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3334;IfcPumpType;"<EPM-HTML> 
 
<p>The flow moving device type <b>IfcPumpType</b> defines commonly shared information for occurrences of pumps.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a pump specification (i.e. the specific product information, that is common to all occurrences of that product type).  Pump types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcPumpType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcpump.htm"">IfcPump</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowmovingdevicetype.htm"">IfcFlowMovingDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_PumpTypeCommon.xml"" target=""SOURCE"">Pset_PumpTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcPumpType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
<li><b>'Impeller'</b>: Material from which the impeller of the pump is constructed. In the case of a positive displacement pump, the piston acts as the impeller.</li> 
<li><b>'ImpellerSeal'</b>: Material from which the impeller shaft seal of the pump is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcPumpType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcpump.htm"">IfcPump</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3347;IfcDamperType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcDamperType</b> defines commonly shared information for occurrences of dampers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a damper specification (i.e. the specific product information, that is common to all occurrences of that product type).  Damper types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcDamperType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcdamper.htm"">IfcDamper</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DamperTypeCommon.xml"" target=""SOURCE"">Pset_DamperTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DamperTypeControlDamper.xml"" target=""SOURCE"">Pset_DamperTypeControlDamper</a> (<a href=""../../ifchvacdomain/lexical/ifcdampertypeenum.htm"">CONTROLDAMPER</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DamperTypeFireDamper.xml"" target=""SOURCE"">Pset_DamperTypeFireDamper</a> (<a href=""../../ifchvacdomain/lexical/ifcdampertypeenum.htm"">FIREDAMPER</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DamperTypeFireSmokeDamper.xml"" target=""SOURCE"">Pset_DamperTypeFireSmokeDamper</a> (<a href=""../../ifchvacdomain/lexical/ifcdampertypeenum.htm"">FIRESMOKEDAMPER</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DamperTypeSmokeDamper.xml"" target=""SOURCE"">Pset_DamperTypeSmokeDamper</a> (<a href=""../../ifchvacdomain/lexical/ifcdampertypeenum.htm"">SMOKEDAMPER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcDamperType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Blade'</b>: The material from which the damper blades are constructed.</li> 
<li><b>'Frame'</b>: The material from which the damper frame is constructed.</li> 
<li><b>'Seal'</b>: The material from which the damper seals are constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcDamperType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcdamper.htm"">IfcDamper</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3364;IfcAirTerminalBoxType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcAirTerminalBoxType</b> defines commonly shared information for occurrences of air boxes.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a air box specification (i.e. the specific product information, that is common to all occurrences of that product type).  Air Box types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcAirTerminalBoxType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcairterminalbox.htm"">IfcAirTerminalBox</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_AirTerminalBoxTypeCommon.xml"" target=""SOURCE"">Pset_AirTerminalBoxTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcAirTerminalBoxType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcAirTerminalBoxType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcairterminalbox.htm"">IfcAirTerminalBox</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3373;IfcValveType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcValveType</b> defines commonly shared information for occurrences of valves.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a valve specification (i.e. the specific product information, that is common to all occurrences of that product type).  Valve types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcValveType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcvalve.htm"">IfcValve</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeCommon.xml"" target=""SOURCE"">Pset_ValveTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeAirRelease.xml"" target=""SOURCE"">Pset_ValveTypeAirRelease</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">AIRRELEASE</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeDrawOffCock.xml"" target=""SOURCE"">Pset_ValveTypeDrawOffCock</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">DRAWOFFCOCK</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeFaucet.xml"" target=""SOURCE"">Pset_ValveTypeFaucet</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">FAUCET</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeFlushing.xml"" target=""SOURCE"">Pset_ValveTypeFlushing</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">FLUSHING</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeGasTap.xml"" target=""SOURCE"">Pset_ValveTypeGasTap</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">GASTAP</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeIsolating.xml"" target=""SOURCE"">Pset_ValveTypeIsolating</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">ISOLATING</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypeMixing.xml"" target=""SOURCE"">Pset_ValveTypeMixing</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">MIXING</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypePressureReducing.xml"" target=""SOURCE"">Pset_ValveTypePressureReducing</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">PRESSUREREDUCING</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_ValveTypePressureRelief.xml"" target=""SOURCE"">Pset_ValveTypePressureRelief</a> (<a href=""../../ifchvacdomain/lexical/ifcvalvetypeenum.htm"">PRESSURERELIEF</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcValveType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
<li><b>'Operation'</b>: Material from which the operating mechanism (gate, globe, plug, needle, clack etc.) of the valve is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcValveType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcvalve.htm"">IfcValve</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3400;IfcFlowMeterType;"<EPM-HTML> 
 
<p>The flow controller type <b>IfcFlowMeterType</b> defines commonly shared information for occurrences of flow meters.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a flow meter specification (i.e. the specific product information, that is common to all occurrences of that product type).  Flow Meter types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcFlowMeterType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcflowmeter.htm"">IfcFlowMeter</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowcontrollertype.htm"">IfcFlowControllerType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FlowMeterTypeCommon.xml"" target=""SOURCE"">Pset_FlowMeterTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FlowMeterTypeEnergyMeter.xml"" target=""SOURCE"">Pset_FlowMeterTypeEnergyMeter</a> (<a href=""../../ifchvacdomain/lexical/ifcflowmetertypeenum.htm"">ENERGYMETER</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FlowMeterTypeGasMeter.xml"" target=""SOURCE"">Pset_FlowMeterTypeGasMeter</a> (<a href=""../../ifchvacdomain/lexical/ifcflowmetertypeenum.htm"">GASMETER</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FlowMeterTypeOilMeter.xml"" target=""SOURCE"">Pset_FlowMeterTypeOilMeter</a> (<a href=""../../ifchvacdomain/lexical/ifcflowmetertypeenum.htm"">OILMETER</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FlowMeterTypeWaterMeter.xml"" target=""SOURCE"">Pset_FlowMeterTypeWaterMeter</a> (<a href=""../../ifchvacdomain/lexical/ifcflowmetertypeenum.htm"">WATERMETER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFlowMeterType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Casing'</b>: Material from which the casing is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcFlowMeterType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcflowmeter.htm"">IfcFlowMeter</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3410;IfcDuctFittingType;"<EPM-HTML> 
 
<p>The flow fitting type <b>IfcDuctFittingType</b> defines commonly shared information for occurrences of duct fittings.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a duct fitting specification (i.e. the specific product information, that is common to all occurrences of that product type).  Duct Fitting types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcDuctFittingType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcductfitting.htm"">IfcDuctFitting</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowfittingtype.htm"">IfcFlowFittingType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DuctFittingTypeCommon.xml"" target=""SOURCE"">Pset_DuctFittingTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcDuctFittingType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: Material from which the duct fitting is constructed.</li> 
<li><b>'Coating'</b>: The outer coating, if applicable.</li> 
<li><b>'Insulation'</b>: The insulating wrapping, if applicable.</li> 
<li><b>'Lining'</b>: The inner lining, if applicable.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcDuctFittingType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcductfitting.htm"">IfcDuctFitting</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3423;IfcPipeFittingType;"<EPM-HTML> 
 
<p>The flow fitting type <b>IfcPipeFittingType</b> defines commonly shared information for occurrences of pipe fittings.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a pipe fitting specification (i.e. the specific product information, that is common to all occurrences of that product type).  Pipe Fitting types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcPipeFittingType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcpipefitting.htm"">IfcPipeFitting</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowfittingtype.htm"">IfcFlowFittingType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_PipeFittingTypeCommon.xml"" target=""SOURCE"">Pset_PipeFittingTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcPipeFittingType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: Material from which the pipe fitting is constructed.</li> 
<li><b>'Coating'</b>: The outer coating, if applicable.</li> 
<li><b>'Insulation'</b>: The insulating wrapping, if applicable.</li> 
<li><b>'Lining'</b>: The inner lining, if applicable.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcPipeFittingType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcpipefitting.htm"">IfcPipeFitting</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3436;IfcTankType;"<EPM-HTML> 
 
<p>The flow storage device type <b>IfcTankType</b> defines commonly shared information for occurrences of tanks.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a tank specification (i.e. the specific product information, that is common to all occurrences of that product type).  Tank types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcTankType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifctank.htm"">IfcTank</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowstoragedevicetype.htm"">IfcFlowStorageDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TankTypeCommon.xml"" target=""SOURCE"">Pset_TankTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TankTypeExpansion.xml"" target=""SOURCE"">Pset_TankTypeExpansion</a> (<a href=""../../ifchvacdomain/lexical/ifctanktypeenum.htm"">EXPANSION</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TankTypePreformed.xml"" target=""SOURCE"">Pset_TankTypePreformed</a> (<a href=""../../ifchvacdomain/lexical/ifctanktypeenum.htm"">PREFORMED</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TankTypePressureVessel.xml"" target=""SOURCE"">Pset_TankTypePressureVessel</a> (<a href=""../../ifchvacdomain/lexical/ifctanktypeenum.htm"">PRESSUREVESSEL</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_TankTypeSectional.xml"" target=""SOURCE"">Pset_TankTypeSectional</a> (<a href=""../../ifchvacdomain/lexical/ifctanktypeenum.htm"">SECTIONAL</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcTankType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcTankType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifctank.htm"">IfcTank</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3449;IfcDuctSilencerType;"<EPM-HTML> 
 
<p>The flow treatment device type <b>IfcDuctSilencerType</b> defines commonly shared information for occurrences of duct silencers.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a duct silencer specification (i.e. the specific product information, that is common to all occurrences of that product type).  Duct Silencer types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcDuctSilencerType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcductsilencer.htm"">IfcDuctSilencer</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowtreatmentdevicetype.htm"">IfcFlowTreatmentDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DuctSilencerTypeCommon.xml"" target=""SOURCE"">Pset_DuctSilencerTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcDuctSilencerType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcDuctSilencerType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcductsilencer.htm"">IfcDuctSilencer</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3458;IfcFilterType;"<EPM-HTML> 
 
<p>The flow treatment device type <b>IfcFilterType</b> defines commonly shared information for occurrences of filters.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a filter specification (i.e. the specific product information, that is common to all occurrences of that product type).  Filter types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcFilterType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcfilter.htm"">IfcFilter</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowtreatmentdevicetype.htm"">IfcFlowTreatmentDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FilterTypeCommon.xml"" target=""SOURCE"">Pset_FilterTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_FilterTypeAirParticleFilter.xml"" target=""SOURCE"">Pset_FilterTypeAirParticleFilter</a> (<a href=""../../ifchvacdomain/lexical/ifcfiltertypeenum.htm"">AIRPARTICLEFILTER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFilterType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Media'</b>: The material that is used for filtering particulates from the fluid.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcFilterType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcfilter.htm"">IfcFilter</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3470;IfcPipeSegmentType;"<EPM-HTML> 
 
<p>The flow segment type <b>IfcPipeSegmentType</b> defines commonly shared information for occurrences of pipe segments.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a pipe segment specification (i.e. the specific product information, that is common to all occurrences of that product type).  Pipe Segment types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcPipeSegmentType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcpipesegment.htm"">IfcPipeSegment</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowsegmenttype.htm"">IfcFlowSegmentType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_PipeSegmentTypeCommon.xml"" target=""SOURCE"">Pset_PipeSegmentTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_PipeSegmentTypeCulvert.xml"" target=""SOURCE"">Pset_PipeSegmentTypeCulvert</a> (<a href=""../../ifchvacdomain/lexical/ifcpipesegmenttypeenum.htm"">CULVERT</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_PipeSegmentTypeGutter.xml"" target=""SOURCE"">Pset_PipeSegmentTypeGutter</a> (<a href=""../../ifchvacdomain/lexical/ifcpipesegmenttypeenum.htm"">GUTTER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcPipeSegmentType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: Material from which the pipe segment is constructed.</li> 
<li><b>'Coating'</b>: The outer coating, if applicable.</li> 
<li><b>'Insulation'</b>: The insulating wrapping, if applicable.</li> 
<li><b>'Lining'</b>: The inner lining, if applicable.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcPipeSegmentType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcpipesegment.htm"">IfcPipeSegment</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3481;IfcDuctSegmentType;"<EPM-HTML> 
 
<p>The flow segment type <b>IfcDuctSegmentType</b> defines commonly shared information for occurrences of duct segments.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a duct segment specification (i.e. the specific product information, that is common to all occurrences of that product type).  Duct Segment types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcDuctSegmentType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcductsegment.htm"">IfcDuctSegment</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowsegmenttype.htm"">IfcFlowSegmentType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_DuctSegmentTypeCommon.xml"" target=""SOURCE"">Pset_DuctSegmentTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcDuctSegmentType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm"">IfcMaterialProfileSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: Material from which the duct segment is constructed.</li> 
<li><b>'Coating'</b>: The outer coating, if applicable.</li> 
<li><b>'Insulation'</b>: The insulating wrapping, if applicable.</li> 
<li><b>'Lining'</b>: The inner lining, if applicable.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcDuctSegmentType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcductsegment.htm"">IfcDuctSegment</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3489;IfcPipeFitting;"<p>A pipe fitting is a junction or transition in a piping flow distribution system or used to connect pipe segments, resulting changes in flow characteristics to the fluid such as direction or flow rate.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcPipeFitting</b> defines the occurrence of any pipe fitting; common information about pipe fitting types is handled by <i>IfcPipeFittingType</i>. 
The <i>IfcPipeFittingType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcPipeFittingType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcPipeFittingType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcPipeFitting</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcPipeFittingType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcPipeFittingType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcPipeFitting</b> override the properties defined at <i>IfcPipeFittingType</i>. 
Refer to the documentation at the supertype <i>IfcFlowFitting</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeFittingOccurrence.xml"">Pset_PipeFittingOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeFittingPHistory.xml"">Pset_PipeFittingPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeFittingTypeCommon.xml"">Pset_PipeFittingTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">BEND</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeFittingTypeBend.xml"">Pset_PipeFittingTypeBend</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">JUNCTION</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeFittingTypeJunction.xml"">Pset_PipeFittingTypeJunction</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_PipeFittingBaseQuantities.xml"">Qto_PipeFittingBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcPipeFitting</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcPipeFittingType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: Material from which the pipe fitting is constructed.</li>
<li><b>Coating</b>: The outer coating, if applicable.</li>
<li><b>Insulation</b>: The insulating wrapping, if applicable.</li>
<li><b>Lining</b>: The inner lining, if applicable.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcPipeFitting</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the pipe fitting occurrence is defined by <i>IfcPipeFittingType</i>, then the port occurrences must reflect those defined at the <i>IfcPipeFittingType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcPipeFitting</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcpipefittingtypeenum.htm"">BEND</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">CONNECTOR</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">ENTRY</a>
<ul>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">EXIT</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">JUNCTION</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The first flow outlet.</li>
<li><b>Outlet#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The second flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcpipefittingtypeenum.htm"">OBSTRUCTION</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
</ul>
<p>Figure 227 illustrates pipe fitting port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcpipefitting-Port.png""></td></tr><tr><td><p class=""figure"">Figure 227 &mdash; Pipe fitting port use</p></td></tr></table>


"
3493;IfcDuctFitting;"<p>A duct fitting is a junction or transition in a ducted flow distribution system or used to connect duct segments, resulting changes in flow characteristics to the fluid such as direction and flow rate.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDuctFitting</b> defines the occurrence of any duct fitting; common information about duct fitting types is handled by <i>IfcDuctFittingType</i>. 
The <i>IfcDuctFittingType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcDuctFittingType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcDuctFittingType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcDuctFitting</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcDuctFittingType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDuctFittingType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcDuctFitting</b> override the properties defined at <i>IfcDuctFittingType</i>. 
Refer to the documentation at the supertype <i>IfcFlowFitting</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctFittingOccurrence.xml"">Pset_DuctFittingOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctFittingPHistory.xml"">Pset_DuctFittingPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctFittingTypeCommon.xml"">Pset_DuctFittingTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_DuctFittingBaseQuantities.xml"">Qto_DuctFittingBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDuctFitting</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcDuctFittingType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: Material from which the duct fitting is constructed.</li>
<li><b>Coating</b>: The outer coating, if applicable.</li>
<li><b>Insulation</b>: The insulating wrapping, if applicable.</li>
<li><b>Lining</b>: The inner lining, if applicable.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcDuctFitting</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the duct fitting occurrence is defined by <i>IfcDuctFittingType</i>, then the port occurrences must reflect those defined at the <i>IfcDuctFittingType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcDuctFitting</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcductfittingtypeenum.htm"">BEND</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcductfittingtypeenum.htm"">CONNECTOR</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcductfittingtypeenum.htm"">ENTRY</a>
<ul>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcductfittingtypeenum.htm"">EXIT</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
</ul>
</li>
<li><a href=""./ifcductfittingtypeenum.htm"">JUNCTION</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The first flow outlet.</li>
<li><b>Outlet#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The second flow outlet.</li>
</ul>
</li>
<li><a href=""./ifcductfittingtypeenum.htm"">OBSTRUCTION</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
</li>
</ul>
<p>Figure 221 illustrates duct fitting port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcductfitting-Port.png""></td></tr><tr><td><p class=""figure"">Figure 221 &mdash; Duct fitting port use</p></td></tr></table>


"
3497;IfcPipeSegment;"<p>A pipe segment is used to typically join two sections of a piping network.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcPipeSegment</b> defines the occurrence of any pipe segment; common information about pipe segment types is handled by <i>IfcPipeSegmentType</i>. 
The <i>IfcPipeSegmentType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcPipeSegmentType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcPipeSegmentType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcPipeSegment</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcPipeSegmentType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcPipeSegmentType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcPipeSegment</b> override the properties defined at <i>IfcPipeSegmentType</i>. 
Refer to the documentation at the supertype <i>IfcFlowSegment</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeConnectionFlanged.xml"">Pset_PipeConnectionFlanged</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeSegmentOccurrence.xml"">Pset_PipeSegmentOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeSegmentPHistory.xml"">Pset_PipeSegmentPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeSegmentTypeCommon.xml"">Pset_PipeSegmentTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcpipesegmenttypeenum.htm"">CULVERT</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeSegmentTypeCulvert.xml"">Pset_PipeSegmentTypeCulvert</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcpipesegmenttypeenum.htm"">GUTTER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PipeSegmentTypeGutter.xml"">Pset_PipeSegmentTypeGutter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_PipeSegmentBaseQuantities.xml"">Qto_PipeSegmentBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcPipeSegment</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcPipeSegmentType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: Material from which the duct fitting is constructed.</li>
<li><b>Coating</b>: The outer coating, if applicable.</li>
<li><b>Insulation</b>: The insulating wrapping, if applicable.</li>
<li><b>Lining</b>: The inner lining, if applicable.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcPipeSegment</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the pipe segment occurrence is defined by <i>IfcPipeSegmentType</i>, then the port occurrences must reflect those defined at the <i>IfcPipeSegmentType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcPipeSegment</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
<p>Figure 228 illustrates pipe segment port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcpipesegment-Port.png""></td></tr><tr><td><p class=""figure"">Figure 228 &mdash; Pipe segment port use</p></td></tr></table>


"
3501;IfcDuctSegment;"<p>A duct segment is used to typically join two sections of duct network.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDuctSegment</b> defines the occurrence of any duct segment; common information about duct segment types is handled by <i>IfcDuctSegmentType</i>. 
The <i>IfcDuctSegmentType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcDuctSegmentType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcDuctSegmentType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcDuctSegment</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcDuctSegmentType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDuctSegmentType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcDuctSegment</b> override the properties defined at <i>IfcDuctSegmentType</i>. 
Refer to the documentation at the supertype <i>IfcFlowSegment</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctSegmentOccurrence.xml"">Pset_DuctSegmentOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctSegmentPHistory.xml"">Pset_DuctSegmentPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctSegmentTypeCommon.xml"">Pset_DuctSegmentTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_DuctSegmentBaseQuantities.xml"">Qto_DuctSegmentBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDuctSegment</b> is defined by <i>IfcMaterialProfileSetUsage</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcDuctSegmentType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialProfileSet.MaterialProfiles[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: Material from which the duct fitting is constructed.</li>
<li><b>Coating</b>: The outer coating, if applicable.</li>
<li><b>Insulation</b>: The insulating wrapping, if applicable.</li>
<li><b>Lining</b>: The inner lining, if applicable.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcDuctSegment</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the duct segment occurrence is defined by <i>IfcDuctSegmentType</i>, then the port occurrences must reflect those defined at the <i>IfcDuctSegmentType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcDuctSegment</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>
<p>Figure 222 illustrates duct segment port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcductsegment-Port.png""></td></tr><tr><td><p class=""figure"">Figure 222 &mdash; Duct segment port use</p></td></tr></table>


"
3505;IfcFilter;"<p>A filter is an apparatus used to remove particulate or gaseous matter from fluids and gases.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcFilter</b> defines the occurrence of any filter; common information about filter types is handled by <i>IfcFilterType</i>. 
The <i>IfcFilterType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcFilterType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcFilterType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcFilter</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcFilterType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcFilterType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcFilter</b> override the properties defined at <i>IfcFilterType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTreatmentDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FilterPHistory.xml"">Pset_FilterPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_FilterTypeCommon.xml"">Pset_FilterTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">AIRPARTICLEFILTER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FilterTypeAirParticleFilter.xml"">Pset_FilterTypeAirParticleFilter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">COMPRESSEDAIRFILTER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FilterTypeCompressedAirFilter.xml"">Pset_FilterTypeCompressedAirFilter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">WATERFILTER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FilterTypeWaterFilter.xml"">Pset_FilterTypeWaterFilter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_FilterBaseQuantities.xml"">Qto_FilterBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFilter</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcFilterType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Frame</b>: The material used to construct the filter housing.</li>
<li><b>Media</b>: The material that is used for filtering particulates.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcFilter</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the filter occurrence is defined by <i>IfcFilterType</i>, then the port occurrences must reflect those defined at the <i>IfcFilterType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcFilter</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcfiltertypeenum.htm"">AIRPARTICLEFILTER</a>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">COMPRESSEDAIRFILTER</a>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">COMPRESSEDAIR</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">COMPRESSEDAIR</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">ODORFILTER</a>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">OILFILTER</a>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">OIL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">OIL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">STRAINER</a>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcfiltertypeenum.htm"">WATERFILTER</a>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
</ul>
<p>Figure 225 illustrates filter port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcfilter-Port.png""></td></tr><tr><td><p class=""figure"">Figure 225 &mdash; Filter port use</p></td></tr></table>


"
3509;IfcDuctSilencer;"<p>A duct silencer is a device that is typically installed inside a duct distribution system for the purpose of reducing the noise levels from air movement, fan noise, etc. in the adjacent space or downstream of the duct silencer device.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDuctSilencer</b> defines the occurrence of any duct silencer; common information about duct silencer types is handled by <i>IfcDuctSilencerType</i>. 
The <i>IfcDuctSilencerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcDuctSilencerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcDuctSilencerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcDuctSilencer</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcDuctSilencerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDuctSilencerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcDuctSilencer</b> override the properties defined at <i>IfcDuctSilencerType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTreatmentDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctSilencerPHistory.xml"">Pset_DuctSilencerPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DuctSilencerTypeCommon.xml"">Pset_DuctSilencerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_DuctSilencerBaseQuantities.xml"">Qto_DuctSilencerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDuctSilencer</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcDuctSilencerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcDuctSilencer</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the duct silencer occurrence is defined by <i>IfcDuctSilencerType</i>, then the port occurrences must reflect those defined at the <i>IfcDuctSilencerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcDuctSilencer</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The flow inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): The flow outlet.</li>
</ul>

"
3513;IfcCompressor;"<p>A compressor is a device that compresses a fluid typically used in a refrigeration circuit.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCompressor</b> defines the occurrence of any compressor; common information about compressor types is handled by <i>IfcCompressorType</i>. 
The <i>IfcCompressorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCompressorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCompressorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCompressor</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCompressorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCompressorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCompressor</b> override the properties defined at <i>IfcCompressorType</i>. 
Refer to the documentation at the supertype <i>IfcFlowMovingDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_CompressorPHistory.xml"">Pset_CompressorPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CompressorTypeCommon.xml"">Pset_CompressorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_CompressorBaseQuantities.xml"">Qto_CompressorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCompressor</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCompressorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Refrigerant</b>: Refrigerant material.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCompressor</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the compressor occurrence is defined by <i>IfcCompressorType</i>, then the port occurrences must reflect those defined at the <i>IfcCompressorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCompressor</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Uncompressed vapor refrigerant entering the compressor.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Compressed vapor refrigerant leaving the compressor.</li>
</ul>
<p>Figure 217 illustrates compressor port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifccompressor-Port.png""></td></tr><tr><td><p class=""figure"">Figure 217 &mdash; Compressor port use</p></td></tr></table>


"
3517;IfcFan;"<p>A fan is a device which imparts mechanical work on a gas. A typical usage of a fan is to induce airflow in a building services air distribution system.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcFan</b> defines the occurrence of any fan; common information about fan types is handled by <i>IfcFanType</i>. 
The <i>IfcFanType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcFanType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcFanType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcFan</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcFanType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcFanType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcFan</b> override the properties defined at <i>IfcFanType</i>. 
Refer to the documentation at the supertype <i>IfcFlowMovingDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FanOccurrence.xml"">Pset_FanOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_FanPHistory.xml"">Pset_FanPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_FanTypeCommon.xml"">Pset_FanTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_FanTypeSmokeControl.xml"">Pset_FanTypeSmokeControl</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfantypeenum.htm"">CENTRIFUGAL</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FanCentrifugal.xml"">Pset_FanCentrifugal</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_FanBaseQuantities.xml"">Qto_FanBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFan</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcFanType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Frame</b>: The material used to construct the fan housing.</li>
<li><b>Wheel</b>: The material used to construct the fan wheel.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcFan</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the fan occurrence is defined by <i>IfcFanType</i>, then the port occurrences must reflect those defined at the <i>IfcFanType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcFan</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming air.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing air.</li>
</ul>
<p>Figure 224 illustrates fan port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcfan-Port.png""></td></tr><tr><td><p class=""figure"">Figure 224 &mdash; Fan port use</p></td></tr></table>


"
3521;IfcPump;"<p>A pump is a device which imparts mechanical work on fluids or slurries to move them through a channel or pipeline. A typical use of a pump is to circulate chilled water or heating hot water in a building services distribution system.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcPump</b> defines the occurrence of any pump; common information about pump types is handled by <i>IfcPumpType</i>. 
The <i>IfcPumpType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcPumpType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcPumpType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcPump</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcPumpType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcPumpType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcPump</b> override the properties defined at <i>IfcPumpType</i>. 
Refer to the documentation at the supertype <i>IfcFlowMovingDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_PumpOccurrence.xml"">Pset_PumpOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PumpPHistory.xml"">Pset_PumpPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_PumpTypeCommon.xml"">Pset_PumpTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_PumpBaseQuantities.xml"">Qto_PumpBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcPump</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcPumpType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Impeller</b>: Material from which the impeller of the pump is constructed. In the case of a positive displacement pump, the piston acts as the impeller. </li>
<li><b>Seal</b>: Material from which the impeller shaft seal of the pump is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcPump</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the pump occurrence is defined by <i>IfcPumpType</i>, then the port occurrences must reflect those defined at the <i>IfcPumpType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcPump</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>In</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Fluid entering pump.</li>
<li><b>Out</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Fluid leaving pump.</li>
</ul>
<p>Figure 229 illustrates pump port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcpump-Port.png""></td></tr><tr><td><p class=""figure"">Figure 229 &mdash; Pump port use</p></td></tr></table>


"
3525;IfcAirTerminal;"<p>An air terminal is a terminating or origination point for the transfer of air between distribution system(s) and one or more spaces. It can also be used for the transfer of air between adjacent spaces.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcAirTerminal</b> defines the occurrence of any air terminal; common information about air terminal types is handled by <i>IfcAirTerminalType</i>. 
The <i>IfcAirTerminalType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcAirTerminalType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcAirTerminalType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcAirTerminal</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 210 illustrates air terminal type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcairterminal-Type.png""></td></tr><tr><td><p class=""figure"">Figure 210 &mdash; Air terminal type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcAirTerminalType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcAirTerminalType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcAirTerminal</b> override the properties defined at <i>IfcAirTerminalType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_AirTerminalOccurrence.xml"">Pset_AirTerminalOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_AirTerminalPHistory.xml"">Pset_AirTerminalPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_AirTerminalTypeCommon.xml"">Pset_AirTerminalTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_AirTerminalBaseQuantities.xml"">Qto_AirTerminalBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcAirTerminal</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcAirTerminalType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcAirTerminal</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the air terminal occurrence is defined by <i>IfcAirTerminalType</i>, then the port occurrences must reflect those defined at the <i>IfcAirTerminalType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcAirTerminal</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcairterminaltypeenum.htm"">DIFFUSER</a>
<ul>
<li><b>Air</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Supply air, typically connected from a duct segment or fitting.</li>
</ul>
</li>
<li><a href=""./ifcairterminaltypeenum.htm"">GRILLE</a>
<ul>
<li><b>Air</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Return air, typically connected to a duct segment or fitting.</li>
</ul>
</li>
<li><a href=""./ifcairterminaltypeenum.htm"">REGISTER</a>
<ul>
<li><b>Air</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Supply air, typically connected from a duct segment or fitting.</li>
</ul>
</li>
</ul>
<p>Figure 211 illustrates air terminal port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcairterminal-Port.png""></td></tr><tr><td><p class=""figure"">Figure 211 &mdash; Air terminal port use</p></td></tr></table>


"
3536;IfcSpaceHeater;"<p>Space heaters utilize a combination of radiation and/or natural convection using a heating source such as electricity, steam or hot water to heat a limited space or area. Examples of space heaters include radiators, convectors, baseboard and finned-tube heaters.</p>
<p><i>IfcUnitaryEquipment</i> should be used for packaged units supporting a combination of heating, cooling, and/or dehumidification; <i>IfcCoil</i> should be used for coil-based floor heating.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcSpaceHeater</b> defines the occurrence of any space heater; common information about space heater types is handled by <i>IfcSpaceHeaterType</i>. 
The <i>IfcSpaceHeaterType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcSpaceHeaterType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcSpaceHeaterType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcSpaceHeater</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcSpaceHeaterType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcSpaceHeaterType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcSpaceHeater</b> override the properties defined at <i>IfcSpaceHeaterType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_SpaceHeaterPHistory.xml"">Pset_SpaceHeaterPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_SpaceHeaterTypeCommon.xml"">Pset_SpaceHeaterTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcspaceheatertypeenum.htm"">CONVECTOR</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_SpaceHeaterTypeConvector.xml"">Pset_SpaceHeaterTypeConvector</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcspaceheatertypeenum.htm"">RADIATOR</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_SpaceHeaterTypeRadiator.xml"">Pset_SpaceHeaterTypeRadiator</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_SpaceHeaterBaseQuantities.xml"">Qto_SpaceHeaterBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcSpaceHeater</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcSpaceHeaterType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcSpaceHeater</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the space heater occurrence is defined by <i>IfcSpaceHeaterType</i>, then the port occurrences must reflect those defined at the <i>IfcSpaceHeaterType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcSpaceHeater</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcspaceheatertypeenum.htm"">CONVECTOR</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
</ul>
</li>
<li><a href=""./ifcspaceheatertypeenum.htm"">RADIATOR</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Water or steam supply.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Water or steam return.</li>
</ul>
</li>
</ul>
<p>Figure 230 illustrates space heater port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcspaceheater-Port.png""></td></tr><tr><td><p class=""figure"">Figure 230 &mdash; Space heater port use</p></td></tr></table>


"
3545;IfcMedicalDevice;"<p>A medical device is attached to a medical piping system and operates upon medical gases to perform a specific function. Medical gases include medical air, medical vacuum, oxygen, carbon dioxide, nitrogen, and nitrous oxide.</p>
<p>Outlets for medical gasses should use <i>IfcValve</i> with PredefinedType equal to GASTAP, containing an <i>IfcDistributionPort</i> with FlowDirection=SINK and PredefinedType equal to COMPRESSEDAIR, VACUUM, or CHEMICAL, and having property sets on the port further indicating the gas type and pressure. Tanks for medical gasses should use <i>IfcTank</i> with PredefinedType equal to PRESSUREVESSEL, containing an <i>IfcDistributionPort</i> with FlowDirection=SOURCE and PredefinedType=CHEMICAL, and having property sets on the port further indicating the gas type and pressure range.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcMedicalDevice</b> defines the occurrence of any medical device; common information about medical device types is handled by <i>IfcMedicalDeviceType</i>. 
The <i>IfcMedicalDeviceType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcMedicalDeviceType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcMedicalDeviceType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcMedicalDevice</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcMedicalDeviceType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcMedicalDeviceType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcMedicalDevice</b> override the properties defined at <i>IfcMedicalDeviceType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_MedicalDeviceTypeCommon.xml"">Pset_MedicalDeviceTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_MedicalDeviceBaseQuantities.xml"">Qto_MedicalDeviceBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcMedicalDevice</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcMedicalDeviceType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcMedicalDevice</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the medical device occurrence is defined by <i>IfcMedicalDeviceType</i>, then the port occurrences must reflect those defined at the <i>IfcMedicalDeviceType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcMedicalDevice</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcmedicaldevicetypeenum.htm"">VACUUMSTATION</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>VacuumOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VACUUM</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Provides suction.</li>
</ul>
</li>
</ul>

"
3557;IfcAirTerminalBox;"<p>An air terminal box typically participates in an HVAC duct distribution system and is used to control or modulate the amount of air delivered to its downstream ductwork. An air terminal box type is often referred to as an ""air flow regulator"".</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcAirTerminalBox</b> defines the occurrence of any air terminal box; common information about air terminal box types is handled by <i>IfcAirTerminalBoxType</i>. 
The <i>IfcAirTerminalBoxType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcAirTerminalBoxType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcAirTerminalBoxType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcAirTerminalBox</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcAirTerminalBoxType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcAirTerminalBoxType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcAirTerminalBox</b> override the properties defined at <i>IfcAirTerminalBoxType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_AirTerminalBoxPHistory.xml"">Pset_AirTerminalBoxPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_AirTerminalBoxTypeCommon.xml"">Pset_AirTerminalBoxTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_AirTerminalBoxBaseQuantities.xml"">Qto_AirTerminalBoxBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcAirTerminalBox</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcAirTerminalBoxType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcAirTerminalBox</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the air terminal box occurrence is defined by <i>IfcAirTerminalBoxType</i>, then the port occurrences must reflect those defined at the <i>IfcAirTerminalBoxType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcAirTerminalBox</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming air.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing regulated air.</li>
</ul>

"
3561;IfcDamper;"<p>A damper typically participates in an HVAC duct distribution system and is used to control or modulate the flow of air.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDamper</b> defines the occurrence of any damper; common information about damper types is handled by <i>IfcDamperType</i>. 
The <i>IfcDamperType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcDamperType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcDamperType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcDamper</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcDamperType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDamperType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcDamper</b> override the properties defined at <i>IfcDamperType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperOccurrence.xml"">Pset_DamperOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperPHistory.xml"">Pset_DamperPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperTypeCommon.xml"">Pset_DamperTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcdampertypeenum.htm"">CONTROLDAMPER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperTypeControlDamper.xml"">Pset_DamperTypeControlDamper</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcdampertypeenum.htm"">FIREDAMPER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperTypeFireDamper.xml"">Pset_DamperTypeFireDamper</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcdampertypeenum.htm"">FIRESMOKEDAMPER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperTypeFireSmokeDamper.xml"">Pset_DamperTypeFireSmokeDamper</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcdampertypeenum.htm"">SMOKEDAMPER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_DamperTypeSmokeDamper.xml"">Pset_DamperTypeSmokeDamper</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_DamperBaseQuantities.xml"">Qto_DamperBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDamper</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcDamperType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Blade</b>: The material from which the damper blades are constructed.</li>
<li><b>Frame</b>: The material from which the damper frame is constructed.</li>
<li><b>Seal</b>: The material from which the damper seals are constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDamper</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuator.htm"">IfcActuator</a></b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>): Indicates an actuator operating on the damper.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcDamper</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the damper occurrence is defined by <i>IfcDamperType</i>, then the port occurrences must reflect those defined at the <i>IfcDamperType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcDamper</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Air entering damper.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Air leaving damper, with flow regulated according to position of damper.</li>
</ul>
<p>Figure 220 illustrates damper port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcdamper-Port.png""></td></tr><tr><td><p class=""figure"">Figure 220 &mdash; Damper port use</p></td></tr></table>


"
3565;IfcFlowMeter;"<p>A flow meter is a device that is used to measure the flow rate in a system.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcFlowMeter</b> defines the occurrence of any flow meter; common information about flow meter types is handled by <i>IfcFlowMeterType</i>. 
The <i>IfcFlowMeterType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcFlowMeterType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcFlowMeterType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcFlowMeter</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcFlowMeterType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcFlowMeterType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcFlowMeter</b> override the properties defined at <i>IfcFlowMeterType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FlowMeterOccurrence.xml"">Pset_FlowMeterOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_FlowMeterTypeCommon.xml"">Pset_FlowMeterTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">ENERGYMETER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FlowMeterTypeEnergyMeter.xml"">Pset_FlowMeterTypeEnergyMeter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">GASMETER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FlowMeterTypeGasMeter.xml"">Pset_FlowMeterTypeGasMeter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">OILMETER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FlowMeterTypeOilMeter.xml"">Pset_FlowMeterTypeOilMeter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">WATERMETER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_FlowMeterTypeWaterMeter.xml"">Pset_FlowMeterTypeWaterMeter</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_FlowMeterBaseQuantities.xml"">Qto_FlowMeterBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFlowMeter</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcFlowMeterType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcFlowMeter</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the flow meter occurrence is defined by <i>IfcFlowMeterType</i>, then the port occurrences must reflect those defined at the <i>IfcFlowMeterType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcFlowMeter</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcflowmetertypeenum.htm"">ENERGYMETER</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet from utility.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Measured use.</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">GASMETER</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet from utility.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Measured use.</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">OILMETER</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">OIL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet from utility.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">OIL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Measured use.</li>
</ul>
</li>
<li><a href=""./ifcflowmetertypeenum.htm"">WATERMETER</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet from utility.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Measured use.</li>
</ul>
</li>
</ul>
<p>Figure 226 illustrates flow meter port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcflowmeter-Port.png""></td></tr><tr><td><p class=""figure"">Figure 226 &mdash; Flow meter port use</p></td></tr></table>


"
3569;IfcValve;"<p>A valve is used in a building services piping distribution system to control or modulate the flow of the fluid.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcValve</b> defines the occurrence of any valve; common information about valve types is handled by <i>IfcValveType</i>. 
The <i>IfcValveType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcValveType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcValveType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcValve</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcValveType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcValveType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcValve</b> override the properties defined at <i>IfcValveType</i>. 
Refer to the documentation at the supertype <i>IfcFlowController</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValvePHistory.xml"">Pset_ValvePHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeCommon.xml"">Pset_ValveTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">AIRRELEASE</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeAirRelease.xml"">Pset_ValveTypeAirRelease</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">DRAWOFFCOCK</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeDrawOffCock.xml"">Pset_ValveTypeDrawOffCock</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">FAUCET</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeFaucet.xml"">Pset_ValveTypeFaucet</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">FLUSHING</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeFlushing.xml"">Pset_ValveTypeFlushing</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">GASTAP</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeGasTap.xml"">Pset_ValveTypeGasTap</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">ISOLATING</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeIsolating.xml"">Pset_ValveTypeIsolating</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">MIXING</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypeMixing.xml"">Pset_ValveTypeMixing</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">PRESSUREREDUCING</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypePressureReducing.xml"">Pset_ValveTypePressureReducing</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">PRESSURERELIEF</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ValveTypePressureRelief.xml"">Pset_ValveTypePressureRelief</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_ValveBaseQuantities.xml"">Qto_ValveBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcValve</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcValveType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Operation</b>: Material from which the operating mechanism (such as gate, globe, plug, needle, or clack) of the valve is constructed.</li>
</ul>

<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcValve</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><b><a href=""../../ifcbuildingcontrolsdomain/lexical/ifcactuator.htm"">IfcActuator</a></b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm"">IfcRelFlowControlElements</a>): Indicates an actuator operating on the valve.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcValve</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the valve occurrence is defined by <i>IfcValveType</i>, then the port occurrences must reflect those defined at the <i>IfcValveType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcValve</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcvalvetypeenum.htm"">AIRRELEASE</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">ANTIVACUUM</a>
<ul>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">CHANGEOVER</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Switched outgoing fluid.</li>
<li><b>Outlet#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Switched outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">CHECK</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">COMMISSIONING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">DIVERTING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
<li><b>Outlet#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">DOUBLECHECK</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">DOUBLEREGULATING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">DRAWOFFCOCK</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">FAUCET</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">FLUSHING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">GASCOCK</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">GASTAP</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">ISOLATING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">MIXING</a>
<ul>
<li><b>Inlet#1</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid to be mixed.</li>
<li><b>Inlet#2</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid to be mixed.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">PRESSUREREDUCING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">PRESSURERELIEF</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">REGULATING</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">SAFETYCUTOFF</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">STEAMTRAP</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing fluid.</li>
</ul>
</li>
<li><a href=""./ifcvalvetypeenum.htm"">STOPCOCK</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming fluid.</li>
</ul>
</li>
</ul>
<p>Figure 233 illustrates valve port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcvalve-Port.png""></td></tr><tr><td><p class=""figure"">Figure 233 &mdash; Valve port use</p></td></tr></table>


"
3573;IfcTank;"<p>A tank is a vessel or container in which a fluid or gas is stored for later use.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcTank</b> defines the occurrence of any tank; common information about tank types is handled by <i>IfcTankType</i>. 
The <i>IfcTankType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcTankType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcTankType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcTank</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcTankType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcTankType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcTank</b> override the properties defined at <i>IfcTankType</i>. 
Refer to the documentation at the supertype <i>IfcFlowStorageDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TankOccurrence.xml"">Pset_TankOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_TankTypeCommon.xml"">Pset_TankTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifctanktypeenum.htm"">EXPANSION</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TankTypeExpansion.xml"">Pset_TankTypeExpansion</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifctanktypeenum.htm"">PREFORMED</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TankTypePreformed.xml"">Pset_TankTypePreformed</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifctanktypeenum.htm"">PRESSUREVESSEL</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TankTypePressureVessel.xml"">Pset_TankTypePressureVessel</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifctanktypeenum.htm"">SECTIONAL</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TankTypeSectional.xml"">Pset_TankTypeSectional</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_TankBaseQuantities.xml"">Qto_TankBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcTank</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcTankType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcTank</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the tank occurrence is defined by <i>IfcTankType</i>, then the port occurrences must reflect those defined at the <i>IfcTankType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcTank</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outlet.</li>
</ul>

"
3577;IfcAirToAirHeatRecovery;"<p>An air-to-air heat recovery device employs a counter-flow heat exchanger between inbound and outbound air flow. It is typically used to transfer heat from warmer air in one chamber to cooler air in the second chamber (i.e., typically used to recover heat from the conditioned air being exhausted and the outside air being supplied to a building), resulting in energy savings from reduced heating (or cooling) requirements.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcAirToAirHeatRecovery</b> defines the occurrence of any air to air heat recovery; common information about air to air heat recovery types is handled by <i>IfcAirToAirHeatRecoveryType</i>. 
The <i>IfcAirToAirHeatRecoveryType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcAirToAirHeatRecoveryType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcAirToAirHeatRecoveryType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcAirToAirHeatRecovery</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcAirToAirHeatRecoveryType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcAirToAirHeatRecoveryType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcAirToAirHeatRecovery</b> override the properties defined at <i>IfcAirToAirHeatRecoveryType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_AirToAirHeatRecoveryPHistory.xml"">Pset_AirToAirHeatRecoveryPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_AirToAirHeatRecoveryTypeCommon.xml"">Pset_AirToAirHeatRecoveryTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_AirToAirHeatRecoveryBaseQuantities.xml"">Qto_AirToAirHeatRecoveryBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcAirToAirHeatRecovery</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcAirToAirHeatRecoveryType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Media</b>: The primary media material used for heat transfer.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcAirToAirHeatRecovery</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the air to air heat recovery occurrence is defined by <i>IfcAirToAirHeatRecoveryType</i>, then the port occurrences must reflect those defined at the <i>IfcAirToAirHeatRecoveryType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcAirToAirHeatRecovery</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>AirInlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold air in.</li>
<li><b>AirOutlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Colder air out.</li>
<li><b>ExhaustInlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot return air in.</li>
<li><b>ExhaustOutlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Hotter return air out.</li>
</ul>

"
3581;IfcBoiler;"<p>A boiler is a closed, pressure-rated vessel in which water or other fluid is heated using an energy source such as natural gas, heating oil, or electricity. The fluid in the vessel is then circulated out of the boiler for use in various processes or heating applications.</p>
<p><i>IfcBoiler</i> is a vessel solely used for heating of water or other fluids. Storage vessels, such as for drinking water storage are considered as tanks and use the <i>IfcTank</i> entity.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcBoiler</b> defines the occurrence of any boiler; common information about boiler types is handled by <i>IfcBoilerType</i>. 
The <i>IfcBoilerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcBoilerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcBoilerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcBoiler</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>
<p>Figure 212 illustrates boiler type use.</p>
<table><tr><td><img alt=""Type Use Definition"" src=""figures/ifcboiler-Type.png""></td></tr><tr><td><p class=""figure"">Figure 212 &mdash; Boiler type use</p></td></tr></table>


<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcBoilerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcBoilerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcBoiler</b> override the properties defined at <i>IfcBoilerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_BoilerPHistory.xml"">Pset_BoilerPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_BoilerTypeCommon.xml"">Pset_BoilerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcboilertypeenum.htm"">STEAM</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_BoilerTypeSteam.xml"">Pset_BoilerTypeSteam</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcboilertypeenum.htm"">WATER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_BoilerTypeWater.xml"">Pset_BoilerTypeWater</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_BoilerBaseQuantities.xml"">Qto_BoilerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcBoiler</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcBoilerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcBoiler</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the boiler occurrence is defined by <i>IfcBoilerType</i>, then the port occurrences must reflect those defined at the <i>IfcBoilerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcBoiler</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcboilertypeenum.htm"">STEAM</a>
<ul>
<li><b>Gas</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Gas inlet for burner.</li>
<li><b>Exhaust</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Exhaust sent to chimney.</li>
<li><b>Condenser</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Water feed such as from condenser.</li>
<li><b>Heating</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Steam sent to heating coils and space heaters.</li>
</ul>
</li>
<li><a href=""./ifcboilertypeenum.htm"">WATER</a>
<ul>
<li><b>Gas</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Gas inlet for burner.</li>
<li><b>Exhaust</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Exhaust sent to chimney.</li>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water to be heated.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Hot water heated.</li>
</ul>
</li>
</ul>
<p>Figure 213 illustrates boiler port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcboiler-Port.png""></td></tr><tr><td><p class=""figure"">Figure 213 &mdash; Boiler port use</p></td></tr></table>


"
3585;IfcBurner;"<p>A burner is a device that converts fuel into heat through combustion. It includes gas, oil, and wood burners.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcBurner</b> defines the occurrence of any burner; common information about burner types is handled by <i>IfcBurnerType</i>. 
The <i>IfcBurnerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcBurnerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcBurnerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcBurner</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcBurnerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcBurnerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcBurner</b> override the properties defined at <i>IfcBurnerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_BurnerTypeCommon.xml"">Pset_BurnerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_BurnerBaseQuantities.xml"">Qto_BurnerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcBurner</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcBurnerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Fuel</b>: Material designed to be burned.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcBurner</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the burner occurrence is defined by <i>IfcBurnerType</i>, then the port occurrences must reflect those defined at the <i>IfcBurnerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcBurner</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Gas</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Gas inlet for burner.</li>
</ul>

"
3589;IfcChiller;"<p>A chiller is a device used to remove heat from a liquid via a vapor-compression or absorption refrigeration cycle to cool a fluid, typically water or a mixture of water and glycol. The chilled fluid is then used to cool and dehumidify air in a building.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcChiller</b> defines the occurrence of any chiller; common information about chiller types is handled by <i>IfcChillerType</i>. 
The <i>IfcChillerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcChillerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcChillerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcChiller</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcChillerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcChillerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcChiller</b> override the properties defined at <i>IfcChillerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_ChillerPHistory.xml"">Pset_ChillerPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_ChillerTypeCommon.xml"">Pset_ChillerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_ChillerBaseQuantities.xml"">Qto_ChillerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcChiller</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcChillerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Refrigerant</b>: Refrigerant material.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcChiller</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcChiller</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li>May contain <i>IfcDistributionElement</i> components. Chillers may aggregate distribution flow elements forming a refrigeration cycle (compressor, condenser, valve, evaporator), as well as control elements.</li>
</ul>
<p>Figure 214 illustrates chiller composition use.</p>
<table><tr><td><img alt=""Composition Use Definition"" src=""figures/ifcchiller-Composition.png""></td></tr><tr><td><p class=""figure"">Figure 214 &mdash; Chiller composition use</p></td></tr></table>


<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcChiller</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the chiller occurrence is defined by <i>IfcChillerType</i>, then the port occurrences must reflect those defined at the <i>IfcChillerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcChiller</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcchillertypeenum.htm"">AIRCOOLED</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Control unit accessing internal sensors and actuators.</li>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water return.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water supply.</li>
<li><b>VentilationIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming cooler air.</li>
<li><b>VentilationOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing hotter air.</li>
</ul>
</li>
<li><a href=""./ifcchillertypeenum.htm"">WATERCOOLED</a>
<ul>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Receives electrical power.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Control unit accessing internal sensors and actuators.</li>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water return.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water supply.</li>
<li><b>CondenserWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming cooled condenser water.</li>
<li><b>CondenserWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing heated condenser water.</li>
</ul>
</li>
</ul>
<p>Figure 215 illustrates chiller port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcchiller-Port.png""></td></tr><tr><td><p class=""figure"">Figure 215 &mdash; Chiller port use</p></td></tr></table>


"
3593;IfcCoil;"<p>A coil is a device used to provide heat transfer between non-mixing media. A common example is a cooling coil, which utilizes a finned coil in which circulates chilled water, antifreeze, or refrigerant that is used to remove heat from air moving across the surface of the coil. A coil may be used either for heating or cooling purposes by placing a series of tubes (the coil) carrying a heating or cooling fluid into an airstream. The coil may be constructed from tubes bundled in a serpentine form or from finned tubes that give a extended heat transfer surface.</p>
<p>Coils may also be used for non-airflow cases such as embedded in a floor slab.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCoil</b> defines the occurrence of any coil; common information about coil types is handled by <i>IfcCoilType</i>. 
The <i>IfcCoilType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCoilType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCoilType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCoil</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCoilType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCoilType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCoil</b> override the properties defined at <i>IfcCoilType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_CoilOccurrence.xml"">Pset_CoilOccurrence</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_OCCURRENCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CoilPHistory.xml"">Pset_CoilPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CoilTypeCommon.xml"">Pset_CoilTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CoilTypeHydronic.xml"">Pset_CoilTypeHydronic</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_CoilBaseQuantities.xml"">Qto_CoilBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCoil</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCoilType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCoil</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the coil occurrence is defined by <i>IfcCoilType</i>, then the port occurrences must reflect those defined at the <i>IfcCoilType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCoil</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccoiltypeenum.htm"">DXCOOLINGCOIL</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Refrigerant entering the coil.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Refrigerant leaving the coil.</li>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Air entering the surface of the coil.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Air leaving the surface of the coil.</li>
</ul>
</li>
<li><a href=""./ifccoiltypeenum.htm"">WATERCOOLINGCOIL</a>
<ul>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water entering the coil.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water leaving the coil.</li>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Air entering the surface of the coil.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Air leaving the surface of the coil.</li>
</ul>
</li>
<li><a href=""./ifccoiltypeenum.htm"">WATERHEATINGCOIL</a>
<ul>
<li><b>HeatingIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Heated water entering the coil.</li>
<li><b>HeatingOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Heated water leaving the coil.</li>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Air entering the surface of the coil.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Air leaving the surface of the coil.</li>
</ul>
</li>
</ul>
<p>Figure 216 illustrates coil port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifccoil-Port.png""></td></tr><tr><td><p class=""figure"">Figure 216 &mdash; Coil port use</p></td></tr></table>


"
3597;IfcCondenser;"<p>A condenser is a device that is used to dissipate heat, typically by condensing a substance such as a refrigerant from its gaseous to its liquid state.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCondenser</b> defines the occurrence of any condenser; common information about condenser types is handled by <i>IfcCondenserType</i>. 
The <i>IfcCondenserType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCondenserType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCondenserType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCondenser</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCondenserType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCondenserType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCondenser</b> override the properties defined at <i>IfcCondenserType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_CondenserPHistory.xml"">Pset_CondenserPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CondenserTypeCommon.xml"">Pset_CondenserTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_CondenserBaseQuantities.xml"">Qto_CondenserBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCondenser</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCondenserType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Refrigerant</b>: Refrigerant material.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCondenser</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the condenser occurrence is defined by <i>IfcCondenserType</i>, then the port occurrences must reflect those defined at the <i>IfcCondenserType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCondenser</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifccondensertypeenum.htm"">AIRCOOLED</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Vapor refrigerant entering the condenser.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Liquid refrigerant leaving the condenser.</li>
<li><b>CompressedAirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">COMPRESSEDAIR</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cooler air entering the condenser.</li>
<li><b>CompressedAirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">COMPRESSEDAIR</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Warmer air leaving the condenser.</li>
</ul>
</li>
<li><a href=""./ifccondensertypeenum.htm"">EVAPORATIVECOOLED</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Vapor refrigerant entering the condenser.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Liquid refrigerant leaving the condenser.</li>
<li><b>CondenserWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Makeup water entering the condenser.</li>
<li><b>CondenserWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Purged water leaving the condenser.</li>
<li><b>VentilationIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Air entering the condenser.</li>
<li><b>VentilationOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Air leaving the condenser.</li>
</ul>
</li>
<li><a href=""./ifccondensertypeenum.htm"">WATERCOOLED</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Vapor refrigerant entering the condenser.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Liquid refrigerant leaving the condenser.</li>
<li><b>CondenserWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cooler water entering the condenser, optionally from cooling tower.</li>
<li><b>CondenserWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Warmer water leaving the condenser, optionally to cooling tower.</li>
</ul>
</li>
</ul>
<p>Figure 218 illustrates condenser port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifccondenser-Port.png""></td></tr><tr><td><p class=""figure"">Figure 218 &mdash; Condenser port use</p></td></tr></table>


"
3601;IfcCooledBeam;"<p>A cooled beam (or chilled beam) is a device typically used to cool air by circulating a fluid such as chilled water through exposed finned tubes above a space. Typically mounted overhead near or within a ceiling, the cooled beam uses convection to cool the space below it by acting as a heat sink for the naturally rising warm air of the space. Once cooled, the air naturally drops back to the floor where the cycle begins again.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCooledBeam</b> defines the occurrence of any cooled beam; common information about cooled beam types is handled by <i>IfcCooledBeamType</i>. 
The <i>IfcCooledBeamType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCooledBeamType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCooledBeamType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCooledBeam</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCooledBeamType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCooledBeamType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCooledBeam</b> override the properties defined at <i>IfcCooledBeamType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_CooledBeamPHistory.xml"">Pset_CooledBeamPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CooledBeamTypeCommon.xml"">Pset_CooledBeamTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifccooledbeamtypeenum.htm"">ACTIVE</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_CooledBeamPHistoryActive.xml"">Pset_CooledBeamPHistoryActive</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CooledBeamTypeActive.xml"">Pset_CooledBeamTypeActive</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_CooledBeamBaseQuantities.xml"">Qto_CooledBeamBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCooledBeam</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCooledBeamType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCooledBeam</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the cooled beam occurrence is defined by <i>IfcCooledBeamType</i>, then the port occurrences must reflect those defined at the <i>IfcCooledBeamType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCooledBeam</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water entering.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water leaving.</li>
</ul>

"
3605;IfcCoolingTower;"<p>A cooling tower is a device which rejects heat to ambient air by circulating a fluid such as water through it to reduce its temperature by partial evaporation.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcCoolingTower</b> defines the occurrence of any cooling tower; common information about cooling tower types is handled by <i>IfcCoolingTowerType</i>. 
The <i>IfcCoolingTowerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcCoolingTowerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcCoolingTowerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcCoolingTower</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcCoolingTowerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcCoolingTowerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcCoolingTower</b> override the properties defined at <i>IfcCoolingTowerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_CoolingTowerPHistory.xml"">Pset_CoolingTowerPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_CoolingTowerTypeCommon.xml"">Pset_CoolingTowerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_CoolingTowerBaseQuantities.xml"">Qto_CoolingTowerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcCoolingTower</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcCoolingTowerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Fill</b>: Fill material.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcCoolingTower</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcCoolingTower</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li><a href=""./ifccoolingtowertypeenum.htm"">MECHANICALFORCEDDRAFT</a>
<ul>
<li>May contain <i>IfcFan</i> components for forcing air into the cooling tower.</li>
</ul>
</li>
<li><a href=""./ifccoolingtowertypeenum.htm"">MECHANICALINDUCEDDDRAFT</a>
<ul>
<li>May contain <i>IfcFan</i> components for inducing air out of the cooling tower.</li>
</ul>
</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcCoolingTower</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the cooling tower occurrence is defined by <i>IfcCoolingTowerType</i>, then the port occurrences must reflect those defined at the <i>IfcCoolingTowerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcCoolingTower</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>CondenserWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Warmer water entering the cooling tower.</li>
<li><b>CondenserWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONDENSERWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Cooler water leaving the cooling tower.</li>
</ul>
<p>Figure 219 illustrates cooling tower port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifccoolingtower-Port.png""></td></tr><tr><td><p class=""figure"">Figure 219 &mdash; Cooling tower port use</p></td></tr></table>


"
3609;IfcEvaporativeCooler;"<p>An evaporative cooler is a device that cools air by saturating it with water vapor.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcEvaporativeCooler</b> defines the occurrence of any evaporative cooler; common information about evaporative cooler types is handled by <i>IfcEvaporativeCoolerType</i>. 
The <i>IfcEvaporativeCoolerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcEvaporativeCoolerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcEvaporativeCoolerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcEvaporativeCooler</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcEvaporativeCoolerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcEvaporativeCoolerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcEvaporativeCooler</b> override the properties defined at <i>IfcEvaporativeCoolerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_EvaporativeCoolerPHistory.xml"">Pset_EvaporativeCoolerPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_EvaporativeCoolerTypeCommon.xml"">Pset_EvaporativeCoolerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_EvaporativeCoolerBaseQuantities.xml"">Qto_EvaporativeCoolerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcEvaporativeCooler</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcEvaporativeCoolerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Media</b>: Heat exchanger media material.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcEvaporativeCooler</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the evaporative cooler occurrence is defined by <i>IfcEvaporativeCoolerType</i>, then the port occurrences must reflect those defined at the <i>IfcEvaporativeCoolerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcEvaporativeCooler</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>WaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming water.</li>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming air.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing air saturated with vapor.</li>
</ul>

"
3613;IfcEvaporator;"<p>An evaporator is a device in which a liquid refrigerent is vaporized and absorbs heat from the surrounding fluid.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcEvaporator</b> defines the occurrence of any evaporator; common information about evaporator types is handled by <i>IfcEvaporatorType</i>. 
The <i>IfcEvaporatorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcEvaporatorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcEvaporatorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcEvaporator</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcEvaporatorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcEvaporatorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcEvaporator</b> override the properties defined at <i>IfcEvaporatorType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_EvaporatorPHistory.xml"">Pset_EvaporatorPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_EvaporatorTypeCommon.xml"">Pset_EvaporatorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_EvaporatorBaseQuantities.xml"">Qto_EvaporatorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcEvaporator</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcEvaporatorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Refrigerant</b>: Refrigerant material.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcEvaporator</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the evaporator occurrence is defined by <i>IfcEvaporatorType</i>, then the port occurrences must reflect those defined at the <i>IfcEvaporatorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcEvaporator</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcevaporatortypeenum.htm"">DIRECTEXPANSION</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Liquid refrigerant entering the evaporator.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Vapor refrigerant leaving the evaporator.</li>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Air return entering the evaporator.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Air supply leaving the evaporator.</li>
</ul>
</li>
<li><a href=""./ifcevaporatortypeenum.htm"">FLOODEDSHELLANDTUBE</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Liquid refrigerant entering the evaporator.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Vapor refrigerant leaving the evaporator.</li>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water return entering the evaporator.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water supply leaving the evaporator.</li>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water return entering the evaporator.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water supply leaving the evaporator.</li>
</ul>
</li>
<li><a href=""./ifcevaporatortypeenum.htm"">SHELLANDCOIL</a>
<ul>
<li><b>RefrigerantIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Liquid refrigerant entering the evaporator.</li>
<li><b>RefrigerantOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">REFRIGERATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Vapor refrigerant leaving the evaporator.</li>
</ul>
</li>
</ul>
<p>Figure 223 illustrates evaporator port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcevaporator-Port.png""></td></tr><tr><td><p class=""figure"">Figure 223 &mdash; Evaporator port use</p></td></tr></table>


"
3617;IfcHeatExchanger;"<p>A heat exchanger is a device used to provide heat transfer between non-mixing media such as plate and shell and tube heat exchangers.</p>
<p><i>IfcHeatExchanger</i> is commonly used on water-side distribution systems to recover energy from a liquid to another liquid (typically water-based), whereas <i>IfcAirToAirHeatRecovery</i> is commonly used on air-side distribution systems to recover energy from a gas to a gas (usually air).</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcHeatExchanger</b> defines the occurrence of any heat exchanger; common information about heat exchanger types is handled by <i>IfcHeatExchangerType</i>. 
The <i>IfcHeatExchangerType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcHeatExchangerType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcHeatExchangerType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcHeatExchanger</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcHeatExchangerType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcHeatExchangerType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcHeatExchanger</b> override the properties defined at <i>IfcHeatExchangerType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_HeatExchangerTypeCommon.xml"">Pset_HeatExchangerTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcheatexchangertypeenum.htm"">PLATE</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_HeatExchangerTypePlate.xml"">Pset_HeatExchangerTypePlate</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_HeatExchangerBaseQuantities.xml"">Qto_HeatExchangerBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcHeatExchanger</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcHeatExchangerType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcHeatExchanger</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the heat exchanger occurrence is defined by <i>IfcHeatExchangerType</i>, then the port occurrences must reflect those defined at the <i>IfcHeatExchangerType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcHeatExchanger</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>HeatingInlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet of substance to be heated.</li>
<li><b>HeatingOutlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outlet of substance to be heated.</li>
<li><b>CoolingInlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet of substance to be cooled.</li>
<li><b>CoolingOutlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outlet of substance to be cooled.</li>
</ul>

"
3621;IfcHumidifier;"<p>A humidifier is a device that adds moisture into the air.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcHumidifier</b> defines the occurrence of any humidifier; common information about humidifier types is handled by <i>IfcHumidifierType</i>. 
The <i>IfcHumidifierType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcHumidifierType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcHumidifierType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcHumidifier</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcHumidifierType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcHumidifierType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcHumidifier</b> override the properties defined at <i>IfcHumidifierType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_HumidifierPHistory.xml"">Pset_HumidifierPHistory</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_PERFORMANCEDRIVEN</a>)</li>
<li><a href=""../../psd/ifchvacdomain/Pset_HumidifierTypeCommon.xml"">Pset_HumidifierTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_HumidifierBaseQuantities.xml"">Qto_HumidifierBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcHumidifier</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcHumidifierType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcHumidifier</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the humidifier occurrence is defined by <i>IfcHumidifierType</i>, then the port occurrences must reflect those defined at the <i>IfcHumidifierType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcHumidifier</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>WaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming water.</li>
<li><b>AirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Incoming air.</li>
<li><b>AirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outgoing air saturated with vapor.</li>
</ul>

"
3625;IfcTubeBundle;"<p>A tube bundle is a device consisting of tubes and bundles of tubes used for heat transfer and contained typically within other energy conversion devices, such as a chiller or coil.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcTubeBundle</b> defines the occurrence of any tube bundle; common information about tube bundle types is handled by <i>IfcTubeBundleType</i>. 
The <i>IfcTubeBundleType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcTubeBundleType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcTubeBundleType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcTubeBundle</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcTubeBundleType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcTubeBundleType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcTubeBundle</b> override the properties defined at <i>IfcTubeBundleType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TubeBundleTypeCommon.xml"">Pset_TubeBundleTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifctubebundletypeenum.htm"">FINNED</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_TubeBundleTypeFinned.xml"">Pset_TubeBundleTypeFinned</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_TubeBundleBaseQuantities.xml"">Qto_TubeBundleBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcTubeBundle</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcTubeBundleType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcTubeBundle</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the tube bundle occurrence is defined by <i>IfcTubeBundleType</i>, then the port occurrences must reflect those defined at the <i>IfcTubeBundleType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcTubeBundle</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outlet.</li>
</ul>

"
3629;IfcUnitaryEquipment;"<p>Unitary equipment typically combine a number of components into a single product, such as air handlers, pre-packaged rooftop air-conditioning units, and split systems.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcUnitaryEquipment</b> defines the occurrence of any unitary equipment; common information about unitary equipment types is handled by <i>IfcUnitaryEquipmentType</i>. 
The <i>IfcUnitaryEquipmentType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcUnitaryEquipmentType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcUnitaryEquipmentType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcUnitaryEquipment</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcUnitaryEquipmentType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcUnitaryEquipmentType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcUnitaryEquipment</b> override the properties defined at <i>IfcUnitaryEquipmentType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_UnitaryEquipmentTypeCommon.xml"">Pset_UnitaryEquipmentTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcunitaryequipmenttypeenum.htm"">AIRCONDITIONINGUNIT</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_UnitaryEquipmentTypeAirConditioningUnit.xml"">Pset_UnitaryEquipmentTypeAirConditioningUnit</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcunitaryequipmenttypeenum.htm"">AIRHANDLER</a>
<ul>
<li><a href=""../../psd/ifchvacdomain/Pset_UnitaryEquipmentTypeAirHandler.xml"">Pset_UnitaryEquipmentTypeAirHandler</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_UnitaryEquipmentBaseQuantities.xml"">Qto_UnitaryEquipmentBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcUnitaryEquipment</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcUnitaryEquipmentType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcUnitaryEquipment</b> may be aggregated into components using <i>IfcRelAggregates</i> where <i>RelatingObject</i> refers to the enclosing <b>IfcUnitaryEquipment</b> and <i>RelatedObjects</i> contains one or more components. Aggregation use is defined for the following predefined types:</p>
<ul>
<li>May contain <i>IfcDistributionElement</i> components. Unitary equipment (air handlers in particular) may elaborate contained elements such as dampers, fans, coils, sensors, actuators, and controllers. Such breakdown provides access to component information and tracking of performance history for embedded elements.</li>
</ul>
<p>Figure 231 illustrates unitary equipment composition use.</p>
<table><tr><td><img alt=""Composition Use Definition"" src=""figures/ifcunitaryequipment-Composition.png""></td></tr><tr><td><p class=""figure"">Figure 231 &mdash; Unitary equipment composition use</p></td></tr></table>


<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcUnitaryEquipment</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the unitary equipment occurrence is defined by <i>IfcUnitaryEquipmentType</i>, then the port occurrences must reflect those defined at the <i>IfcUnitaryEquipmentType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcUnitaryEquipment</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcunitaryequipmenttypeenum.htm"">AIRHANDLER</a>
<ul>
<li><b>ReturnAirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Return air entering mixture or exhausted.</li>
<li><b>SupplyAirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">AIRCONDITIONING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled supply air.</li>
<li><b>OutsideAirIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">VENTILATION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Outside air entering mixture.</li>
<li><b>ExhaustAirOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Exhaust air leaving to outside.</li>
<li><b>ChilledWaterIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Chilled water entering cooling coil.</li>
<li><b>ChilledWaterOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CHILLEDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Chilled water leaving cooling coil.</li>
<li><b>HeatingIn</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Steam entering heating coil.</li>
<li><b>HeatingOut</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">HEATING</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Steam leaving heating coil.</li>
<li><b>Power</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">ELECTRICAL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Electrical power source.</li>
<li><b>Control</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">CONTROL</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Control system communication.</li>
</ul>
</li>
</ul>
<p>Figure 232 illustrates unitary equipment port use.</p>
<table><tr><td><img alt=""Port Use Definition"" src=""figures/ifcunitaryequipment-Port.png""></td></tr><tr><td><p class=""figure"">Figure 232 &mdash; Unitary equipment port use</p></td></tr></table>


"
3633;IfcEngine;"<p>An engine is a device that converts fuel into mechanical energy through combustion.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcEngine</b> defines the occurrence of any engine; common information about engine types is handled by <i>IfcEngineType</i>. 
The <i>IfcEngineType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcEngineType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcEngineType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcEngine</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcEngineType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcEngineType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcEngine</b> override the properties defined at <i>IfcEngineType</i>. 
Refer to the documentation at the supertype <i>IfcEnergyConversionDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_EngineTypeCommon.xml"">Pset_EngineTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_EngineBaseQuantities.xml"">Qto_EngineBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcEngine</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcEngineType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcEngine</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the engine occurrence is defined by <i>IfcEngineType</i>, then the port occurrences must reflect those defined at the <i>IfcEngineType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcEngine</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Fuel</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">GAS</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): The fuel inlet.</li>
<li><b>Drive</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">NOTDEFINED</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Connection to the driven source.</li>
</ul>

"
3637;IfcAirTerminalType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcAirTerminalType</b> defines commonly shared information for occurrences of air terminals.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a air terminal specification (i.e. the specific product information, that is common to all occurrences of that product type).  Air Terminal types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcAirTerminalType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcairterminal.htm"">IfcAirTerminal</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_AirTerminalTypeCommon.xml"" target=""SOURCE"">Pset_AirTerminalTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcAirTerminalType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcAirTerminalType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcairterminal.htm"">IfcAirTerminal</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3640;IfcSpaceHeaterType;"<EPM-HTML> 
 
<p>The energy conversion device type <b>IfcSpaceHeaterType</b> defines commonly shared information for occurrences of space heaters.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a space heater specification (i.e. the specific product information, that is common to all occurrences of that product type).  Space Heater types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcSpaceHeaterType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcspaceheater.htm"">IfcSpaceHeater</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcenergyconversiondevicetype.htm"">IfcEnergyConversionDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_SpaceHeaterTypeCommon.xml"" target=""SOURCE"">Pset_SpaceHeaterTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_SpaceHeaterTypeConvector.xml"" target=""SOURCE"">Pset_SpaceHeaterTypeConvector</a> (<a href=""../../ifchvacdomain/lexical/ifcspaceheatertypeenum.htm"">CONVECTOR</a>)</li> 
<li><a href=""../../psd/IfcHvacDomain/Pset_SpaceHeaterTypeRadiator.xml"" target=""SOURCE"">Pset_SpaceHeaterTypeRadiator</a> (<a href=""../../ifchvacdomain/lexical/ifcspaceheatertypeenum.htm"">RADIATOR</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSpaceHeaterType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcSpaceHeaterType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcspaceheater.htm"">IfcSpaceHeater</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3643;IfcMedicalDeviceType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcMedicalDeviceType</b> defines commonly shared information for occurrences of medical devices.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a medical device specification (i.e. the specific product information, that is common to all occurrences of that product type).  Medical Device types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcMedicalDeviceType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcmedicaldevice.htm"">IfcMedicalDevice</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_MedicalDeviceTypeCommon.xml"" target=""SOURCE"">Pset_MedicalDeviceTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcMedicalDeviceType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcMedicalDeviceType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifchvacdomain/lexical/ifcmedicaldevice.htm"">IfcMedicalDevice</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3646;IfcVibrationIsolator;"<p>A vibration isolator is a device used to minimize the effects of vibration transmissibility in a building.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcVibrationIsolator</b> defines the occurrence of any vibration isolator; common information about vibration isolator types is handled by <i>IfcVibrationIsolatorType</i>. 
The <i>IfcVibrationIsolatorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, composition, assignments, and representations. 
The <i>IfcVibrationIsolatorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcVibrationIsolatorType</i> has aggregated elements, such objects are reflected at the <b>IfcVibrationIsolator</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcVibrationIsolatorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcVibrationIsolatorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcVibrationIsolator</b> override the properties defined at <i>IfcVibrationIsolatorType</i>. 
Refer to the documentation at the supertype <i>IfcElementComponent</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifchvacdomain/Pset_VibrationIsolatorTypeCommon.xml"">Pset_VibrationIsolatorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifchvacdomain/Qto_VibrationIsolatorBaseQuantities.xml"">Qto_VibrationIsolatorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcVibrationIsolator</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcVibrationIsolatorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Damping</b>: Material from which the damping element of the vibration isolator is constructed.</li>
</ul>

"
3655;IfcVibrationIsolatorType;"<EPM-HTML> 
 
<p>The element component type <b>IfcVibrationIsolatorType</b> defines commonly shared information for occurrences of vibration isolators.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a vibration isolator specification (i.e. the specific product information, that is common to all occurrences of that product type).  Vibration Isolator types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcVibrationIsolatorType</b> are represented by instances of <a href=""../../ifchvacdomain/lexical/ifcvibrationisolator.htm"">IfcVibrationIsolator</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedcomponentelements/lexical/ifcelementcomponenttype.htm"">IfcElementComponentType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcHvacDomain/Pset_VibrationIsolatorTypeCommon.xml"" target=""SOURCE"">Pset_VibrationIsolatorTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcVibrationIsolatorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Damping'</b>: Material from which the damping element of the vibration isolator is constructed.</li> 
</ul> 
 
</EPM-HTML>"
3659;IfcWasteTerminalType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcWasteTerminalType</b> defines commonly shared information for occurrences of waste terminals.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a waste terminal specification (i.e. the specific product information, that is common to all occurrences of that product type).  Waste Terminal types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcWasteTerminalType</b> are represented by instances of <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminal.htm"">IfcWasteTerminal</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeCommon.xml"" target=""SOURCE"">Pset_WasteTerminalTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeFloorTrap.xml"" target=""SOURCE"">Pset_WasteTerminalTypeFloorTrap</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">FLOORTRAP</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeFloorWaste.xml"" target=""SOURCE"">Pset_WasteTerminalTypeFloorWaste</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">FLOORWASTE</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeGullySump.xml"" target=""SOURCE"">Pset_WasteTerminalTypeGullySump</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">GULLYSUMP</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeGullyTrap.xml"" target=""SOURCE"">Pset_WasteTerminalTypeGullyTrap</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">GULLYTRAP</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeRoofDrain.xml"" target=""SOURCE"">Pset_WasteTerminalTypeRoofDrain</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">ROOFDRAIN</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeWasteDisposalUnit.xml"" target=""SOURCE"">Pset_WasteTerminalTypeWasteDisposalUnit</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">WASTEDISPOSALUNIT</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_WasteTerminalTypeWasteTrap.xml"" target=""SOURCE"">Pset_WasteTerminalTypeWasteTrap</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminaltypeenum.htm"">WASTETRAP</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcWasteTerminalType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
<li><b>'Cover'</b>: Material from which the cover or grating is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcWasteTerminalType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcwasteterminal.htm"">IfcWasteTerminal</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3672;IfcStackTerminalType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcStackTerminalType</b> defines commonly shared information for occurrences of stack terminals.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a stack terminal specification (i.e. the specific product information, that is common to all occurrences of that product type).  Stack Terminal types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcStackTerminalType</b> are represented by instances of <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcstackterminal.htm"">IfcStackTerminal</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_StackTerminalTypeCommon.xml"" target=""SOURCE"">Pset_StackTerminalTypeCommon</a></li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcStackTerminalType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcStackTerminalType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcstackterminal.htm"">IfcStackTerminal</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3681;IfcSanitaryTerminalType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcSanitaryTerminalType</b> defines commonly shared information for occurrences of sanitary terminals.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a sanitary terminal specification (i.e. the specific product information, that is common to all occurrences of that product type).  Sanitary Terminal types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcSanitaryTerminalType</b> are represented by instances of <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminal.htm"">IfcSanitaryTerminal</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeCommon.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeBath.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeBath</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">BATH</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeBidet.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeBidet</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">BIDET</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeCistern.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeCistern</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">CISTERN</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeSanitaryFountain.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeSanitaryFountain</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">SANITARYFOUNTAIN</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeShower.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeShower</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">SHOWER</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeSink.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeSink</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">SINK</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeToiletPan.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeToiletPan</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">TOILETPAN</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeUrinal.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeUrinal</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">URINAL</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_SanitaryTerminalTypeWashHandBasin.xml"" target=""SOURCE"">Pset_SanitaryTerminalTypeWashHandBasin</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminaltypeenum.htm"">WASHHANDBASIN</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcSanitaryTerminalType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcSanitaryTerminalType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcsanitaryterminal.htm"">IfcSanitaryTerminal</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3697;IfcFireSuppressionTerminalType;"<EPM-HTML> 
 
<p>The flow terminal type <b>IfcFireSuppressionTerminalType</b> defines commonly shared information for occurrences of fire suppression terminals.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a fire suppression terminal specification (i.e. the specific product information, that is common to all occurrences of that product type).  Fire Suppression Terminal types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcFireSuppressionTerminalType</b> are represented by instances of <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcfiresuppressionterminal.htm"">IfcFireSuppressionTerminal</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x2<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowterminaltype.htm"">IfcFlowTerminalType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_FireSuppressionTerminalTypeCommon.xml"" target=""SOURCE"">Pset_FireSuppressionTerminalTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_FireSuppressionTerminalTypeBreechingInlet.xml"" target=""SOURCE"">Pset_FireSuppressionTerminalTypeBreechingInlet</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcfiresuppressionterminaltypeenum.htm"">BREECHINGINLET</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_FireSuppressionTerminalTypeFireHydrant.xml"" target=""SOURCE"">Pset_FireSuppressionTerminalTypeFireHydrant</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcfiresuppressionterminaltypeenum.htm"">FIREHYDRANT</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_FireSuppressionTerminalTypeHoseReel.xml"" target=""SOURCE"">Pset_FireSuppressionTerminalTypeHoseReel</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcfiresuppressionterminaltypeenum.htm"">HOSEREEL</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_FireSuppressionTerminalTypeSprinkler.xml"" target=""SOURCE"">Pset_FireSuppressionTerminalTypeSprinkler</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcfiresuppressionterminaltypeenum.htm"">SPRINKLER</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcFireSuppressionTerminalType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
<li><b>'Deflector'</b>: The material used to construct the deflector plate.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcFireSuppressionTerminalType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcfiresuppressionterminal.htm"">IfcFireSuppressionTerminal</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3708;IfcFireSuppressionTerminal;"<p>A fire suppression terminal has the purpose of delivering a fluid (gas or liquid) that will suppress a fire.</p>
<p>A fire suppression terminal provides for all forms of sprinkler, spreader and other form of terminal that is connected to a pipework system and intended to act in the role of suppressing a fire.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcFireSuppressionTerminal</b> defines the occurrence of any fire suppression terminal; common information about fire suppression terminal types is handled by <i>IfcFireSuppressionTerminalType</i>. 
The <i>IfcFireSuppressionTerminalType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcFireSuppressionTerminalType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcFireSuppressionTerminalType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcFireSuppressionTerminal</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcFireSuppressionTerminalType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcFireSuppressionTerminalType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcFireSuppressionTerminal</b> override the properties defined at <i>IfcFireSuppressionTerminalType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_FireSuppressionTerminalTypeCommon.xml"">Pset_FireSuppressionTerminalTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiresuppressionterminaltypeenum.htm"">BREECHINGINLET</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_FireSuppressionTerminalTypeBreechingInlet.xml"">Pset_FireSuppressionTerminalTypeBreechingInlet</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiresuppressionterminaltypeenum.htm"">FIREHYDRANT</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_FireSuppressionTerminalTypeFireHydrant.xml"">Pset_FireSuppressionTerminalTypeFireHydrant</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiresuppressionterminaltypeenum.htm"">HOSEREEL</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_FireSuppressionTerminalTypeHoseReel.xml"">Pset_FireSuppressionTerminalTypeHoseReel</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcfiresuppressionterminaltypeenum.htm"">SPRINKLER</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_FireSuppressionTerminalTypeSprinkler.xml"">Pset_FireSuppressionTerminalTypeSprinkler</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcplumbingfireprotectiondomain/Qto_FireSuppressionTerminalBaseQuantities.xml"">Qto_FireSuppressionTerminalBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFireSuppressionTerminal</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcFireSuppressionTerminalType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Deflector</b>: The material used to construct the deflector plate.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcFireSuppressionTerminal</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the fire suppression terminal occurrence is defined by <i>IfcFireSuppressionTerminalType</i>, then the port occurrences must reflect those defined at the <i>IfcFireSuppressionTerminalType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcFireSuppressionTerminal</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcfiresuppressionterminaltypeenum.htm"">FIREHYDRANT</a>
<ul>
<li><b>Hose</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">FIREPROTECTION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Fire protection.</li>
</ul>
</li>
<li><a href=""./ifcfiresuppressionterminaltypeenum.htm"">SPRINKLER</a>
<ul>
<li><b>Line</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">FIREPROTECTION</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Fire protection.</li>
</ul>
</li>
</ul>

"
3712;IfcSanitaryTerminal;"<p>A sanitary terminal is a fixed appliance or terminal usually supplied with water and used for drinking, cleaning or foul water disposal or that is an item of equipment directly used with such an appliance or terminal.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcSanitaryTerminal</b> defines the occurrence of any sanitary terminal; common information about sanitary terminal types is handled by <i>IfcSanitaryTerminalType</i>. 
The <i>IfcSanitaryTerminalType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcSanitaryTerminalType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcSanitaryTerminalType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcSanitaryTerminal</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcSanitaryTerminalType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcSanitaryTerminalType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcSanitaryTerminal</b> override the properties defined at <i>IfcSanitaryTerminalType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeCommon.xml"">Pset_SanitaryTerminalTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">BATH</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeBath.xml"">Pset_SanitaryTerminalTypeBath</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">BIDET</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeBidet.xml"">Pset_SanitaryTerminalTypeBidet</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">CISTERN</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeCistern.xml"">Pset_SanitaryTerminalTypeCistern</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">SANITARYFOUNTAIN</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeSanitaryFountain.xml"">Pset_SanitaryTerminalTypeSanitaryFountain</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">SHOWER</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeShower.xml"">Pset_SanitaryTerminalTypeShower</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">SINK</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeSink.xml"">Pset_SanitaryTerminalTypeSink</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">TOILETPAN</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeToiletPan.xml"">Pset_SanitaryTerminalTypeToiletPan</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">URINAL</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeUrinal.xml"">Pset_SanitaryTerminalTypeUrinal</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">WASHHANDBASIN</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_SanitaryTerminalTypeWashHandBasin.xml"">Pset_SanitaryTerminalTypeWashHandBasin</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcplumbingfireprotectiondomain/Qto_SanitaryTerminalBaseQuantities.xml"">Qto_SanitaryTerminalBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcSanitaryTerminal</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcSanitaryTerminalType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcSanitaryTerminal</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the sanitary terminal occurrence is defined by <i>IfcSanitaryTerminalType</i>, then the port occurrences must reflect those defined at the <i>IfcSanitaryTerminalType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcSanitaryTerminal</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">BATH</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
<li><b>Drainage</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">BIDET</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
<li><b>Drainage</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">CISTERN</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">SANITARYFOUNTAIN</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">SHOWER</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
<li><b>Drainage</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">SINK</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
<li><b>Drainage</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">TOILETPAN</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">URINAL</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
</ul>
</li>
<li><a href=""./ifcsanitaryterminaltypeenum.htm"">WASHHANDBASIN</a>
<ul>
<li><b>ColdWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICCOLDWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Cold water supply.</li>
<li><b>HotWater</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DOMESTICHOTWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Hot water supply.</li>
<li><b>Drainage</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage.</li>
</ul>
</li>
</ul>

"
3716;IfcStackTerminal;"<p>A stack terminal is placed at the top of a ventilating stack (such as to prevent ingress by birds or rainwater) or rainwater pipe (to act as a collector or hopper for discharge from guttering).</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcStackTerminal</b> defines the occurrence of any stack terminal; common information about stack terminal types is handled by <i>IfcStackTerminalType</i>. 
The <i>IfcStackTerminalType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcStackTerminalType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcStackTerminalType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcStackTerminal</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcStackTerminalType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcStackTerminalType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcStackTerminal</b> override the properties defined at <i>IfcStackTerminalType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_StackTerminalTypeCommon.xml"">Pset_StackTerminalTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcplumbingfireprotectiondomain/Qto_StackTerminalBaseQuantities.xml"">Qto_StackTerminalBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcStackTerminal</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcStackTerminalType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcStackTerminal</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the stack terminal occurrence is defined by <i>IfcStackTerminalType</i>, then the port occurrences must reflect those defined at the <i>IfcStackTerminalType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcStackTerminal</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcstackterminaltypeenum.htm"">BIRDCAGE</a>
<ul>
<li><b>Exhaust</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Exhaust inlet.</li>
</ul>
</li>
<li><a href=""./ifcstackterminaltypeenum.htm"">COWL</a>
<ul>
<li><b>Exhaust</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">EXHAUST</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Exhaust inlet.</li>
</ul>
</li>
<li><a href=""./ifcstackterminaltypeenum.htm"">RAINWATERHOPPER</a>
<ul>
<li><b>Rain</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">RAINWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Rainwater outlet.</li>
</ul>
</li>
</ul>

"
3720;IfcWasteTerminal;"<p>A waste terminal has the purpose of collecting or intercepting waste from one or more sanitary terminals or other fluid waste generating equipment and discharging it into a single waste/drainage system.</p>
<p>A waste terminal provides for all forms of trap and waste point that collects discharge from a sanitary terminal and discharges it into a waste/drainage subsystem or that collects waste from several terminals and passes it into a single waste/drainage subsystem. This includes the P and S traps from soil sanitary terminals, sinks, and basins as well as floor wastes and gully traps that provide collection points.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcWasteTerminal</b> defines the occurrence of any waste terminal; common information about waste terminal types is handled by <i>IfcWasteTerminalType</i>. 
The <i>IfcWasteTerminalType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcWasteTerminalType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcWasteTerminalType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcWasteTerminal</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcWasteTerminalType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcWasteTerminalType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcWasteTerminal</b> override the properties defined at <i>IfcWasteTerminalType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTerminal</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeCommon.xml"">Pset_WasteTerminalTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">FLOORTRAP</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeFloorTrap.xml"">Pset_WasteTerminalTypeFloorTrap</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">FLOORWASTE</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeFloorWaste.xml"">Pset_WasteTerminalTypeFloorWaste</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">GULLYSUMP</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeGullySump.xml"">Pset_WasteTerminalTypeGullySump</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">GULLYTRAP</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeGullyTrap.xml"">Pset_WasteTerminalTypeGullyTrap</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">ROOFDRAIN</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeRoofDrain.xml"">Pset_WasteTerminalTypeRoofDrain</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">WASTEDISPOSALUNIT</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeWasteDisposalUnit.xml"">Pset_WasteTerminalTypeWasteDisposalUnit</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">WASTETRAP</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_WasteTerminalTypeWasteTrap.xml"">Pset_WasteTerminalTypeWasteTrap</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcplumbingfireprotectiondomain/Qto_WasteTerminalBaseQuantities.xml"">Qto_WasteTerminalBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcWasteTerminal</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcWasteTerminalType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Cover</b>: Material from which the cover or grating is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcWasteTerminal</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the waste terminal occurrence is defined by <i>IfcWasteTerminalType</i>, then the port occurrences must reflect those defined at the <i>IfcWasteTerminalType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcWasteTerminal</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><a href=""./ifcwasteterminaltypeenum.htm"">FLOORTRAP</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Drainage inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage outlet.</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">FLOORWASTE</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Waste inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Waste outlet.</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">GULLYSUMP</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Drainage inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage outlet.</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">GULLYTRAP</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Waste inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Waste outlet.</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">ROOFDRAIN</a>
<ul>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">RAINWATER</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Rainwater.</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">WASTEDISPOSALUNIT</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Waste inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Drainage outlet.</li>
</ul>
</li>
<li><a href=""./ifcwasteterminaltypeenum.htm"">WASTETRAP</a>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Waste inlet.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">WASTE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Waste outlet.</li>
</ul>
</li>
</ul>

"
3724;IfcInterceptorType;"<EPM-HTML> 
 
<p>The flow treatment device type <b>IfcInterceptorType</b> defines commonly shared information for occurrences of interceptors.  The set of shared information may include:</p> 
<ul> 
<li>common properties with shared property sets</li> 
<li>common representations of shape</li> 
<li>common materials</li> 
<li>common composition of elements</li> 
<li>common ports</li> 
<li>applicable assignment of process types</li> 
</ul> 
<p>It is used to define a interceptor specification (i.e. the specific product information, that is common to all occurrences of that product type).  Interceptor types may be exchanged without being already assigned to occurrences.
  Occurrences of <b>IfcInterceptorType</b> are represented by instances of <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcinterceptor.htm"">IfcInterceptor</a>.</p> 
 
<blockquote><font color=""#0000ff"" size=""-1"">HISTORY: New entity in IFC2x4<br></font></blockquote> 
 
<p><b><u>Property Set Use Definition</u></b></p> 
<p>The property sets relating to this entity are defined by <a href=""../../ifckernel/lexical/ifcpropertyset.htm"">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.  Refer to the documentation at the supertype <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowtreatmentdevicetype.htm"">IfcFlowTreatmentDeviceType</a> and ancestors for inherited property set definitions.</p> 
<p>The following property set definitions are applicable to this entity:</p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_InterceptorTypeCommon.xml"" target=""SOURCE"">Pset_InterceptorTypeCommon</a></li> 
</ul> 
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_InterceptorTypeGrease.xml"" target=""SOURCE"">Pset_InterceptorTypeGrease</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcinterceptortypeenum.htm"">GREASE</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_InterceptorTypeOil.xml"" target=""SOURCE"">Pset_InterceptorTypeOil</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcinterceptortypeenum.htm"">OIL</a>)</li> 
<li><a href=""../../psd/IfcPlumbingFireProtectionDomain/Pset_InterceptorTypePetrol.xml"" target=""SOURCE"">Pset_InterceptorTypePetrol</a> (<a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcinterceptortypeenum.htm"">PETROL</a>)</li> 
</ul> 
 
<p><b><u>Material Use Definition</u></b></p> 
<p>The material of the <b>IfcInterceptorType</b> is defined by <a href=""../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm"">IfcMaterialConstituentSet</a> or as a fallback by <a href=""../../ifcmaterialresource/lexical/ifcmaterial.htm"">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href=""../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm"">IfcRelAssociatesMaterial</a> relationship.  It is accessible by the <i>HasAssociations</i> inverse attribute.    The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p> 
<ul> 
<li><b>'Body'</b>: The primary material from which the object is constructed.</li> 
<li><b>'Cover'</b>: Material from which the cover or grating is constructed.</li> 
<li><b>'Strainer'</b>: Material from which the strainer is constructed.</li> 
</ul> 
 
<p><b><u>Port Use Definition</u></b></p> 
<p>The distribution ports relating to the <b>IfcInterceptorType</b> type are defined by <a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm"">IfcDistributionPort</a> and attached by the <a href=""../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm"">IfcRelConnectsPortToElement</a> relationship.  Ports are reflected at occurrences of this type using the <a href=""../../ifckernel/lexical/ifcreldefinesbyobject.htm"">IfcRelDefinesByObject</a> relationship.  Refer to the documentation at <a href=""../../ifcplumbingfireprotectiondomain/lexical/ifcinterceptor.htm"">IfcInterceptor</a> for standard port definitions.</p> 
 
</EPM-HTML>"
3734;IfcInterceptor;"<p>An interceptor is a device designed and installed in order to separate and retain deleterious, hazardous or undesirable matter while permitting normal sewage or liquids to discharge into a collection system by gravity.</p> 
 
<blockquote class=""history"">HISTORY&nbsp; New entity in IFC2x4</blockquote><blockquote class=""note""></blockquote>

<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcInterceptor</b> defines the occurrence of any interceptor; common information about interceptor types is handled by <i>IfcInterceptorType</i>. 
The <i>IfcInterceptorType</i> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. 
The <i>IfcInterceptorType</i> is attached using the <i>IfcRelDefinesByType</i> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. 
If the <i>IfcInterceptorType</i> has ports or aggregated elements, such objects are reflected at the <b>IfcInterceptor</b> occurrence using the <i>IfcRelDefinesByObject</i> relationship.</p>

<p><b><u>Property Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute. 
Property sets may also be specified at the <i>IfcInterceptorType</i>, defining the common property data for all occurrences of the same type. 
They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcInterceptorType</i>.<i>HasPropertySets</i>. 
If both are given, then the properties directly defined at <b>IfcInterceptor</b> override the properties defined at <i>IfcInterceptorType</i>. 
Refer to the documentation at the supertype <i>IfcFlowTreatmentDevice</i> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><b>(All Types)</b>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_InterceptorTypeCommon.xml"">Pset_InterceptorTypeCommon</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcinterceptortypeenum.htm"">GREASE</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_InterceptorTypeGrease.xml"">Pset_InterceptorTypeGrease</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcinterceptortypeenum.htm"">OIL</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_InterceptorTypeOil.xml"">Pset_InterceptorTypeOil</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
<li><a href=""./ifcinterceptortypeenum.htm"">PETROL</a>
<ul>
<li><a href=""../../psd/ifcplumbingfireprotectiondomain/Pset_InterceptorTypePetrol.xml"">Pset_InterceptorTypePetrol</a> (<a href=""../../ifckernel/lexical/ifcpropertysettemplatetypeenum.htm"">PSET_TYPEDRIVENOVERRIDE</a>)</li>
</ul>
</li>
</ul>

<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to this entity are defined by <i>IfcElementQuantity</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. 
They are accessible by the <i>IsDefinedBy</i> inverse attribute.</p>
<p>The following base quantities are defined and shall be exchanged with the <i>IfcElementQuantity</i>.<i>Name</i> = 'BaseQuantities'. 
Other quantities, being subjected to local standard of measurement, may be defined with another string value assigned to <i>Name</i>. 
In this case a valid value for <i>MethodOfMeasurement</i> shall be provided. </p>
<ul>
<li><a href=""../../qto/ifcplumbingfireprotectiondomain/Qto_InterceptorBaseQuantities.xml"">Qto_InterceptorBaseQuantities</a></li>
</ul>

<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcInterceptor</b> is defined by <i>IfcMaterialConstituentSet</i> or as a fallback by <i>IfcMaterial</i>, and attached by the <i>RelatingMaterial</i> attribute on the <i>IfcRelAssociatesMaterial</i> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <i>IfcInterceptorType</i>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:
<ul>
<li><b>Body</b>: The primary material from which the object is constructed.</li>
<li><b>Cover</b>: Material from which the cover or grating is constructed.</li>
<li><b>Strainer</b>: Material from which the strainer is constructed.</li>
</ul>

<p><b><u>Port Use Definition</u></b></p>
<p>The distribution ports relating to the <b>IfcInterceptor</b> are defined by <i>IfcDistributionPort</i> and attached by the <i>IfcRelConnectsPortToElement</i> relationship. 
          If the interceptor occurrence is defined by <i>IfcInterceptorType</i>, then the port occurrences must reflect those defined at the <i>IfcInterceptorType</i> using the <i>IfcRelDefinesByObject</i> relationship.
          Ports are specific to the <b>IfcInterceptor</b> PredefinedType as follows indicated by the <i>IfcDistributionPort</i> <i>Name</i>, <i>PredefinedType</i>, and <i>FlowDirection</i>:</p>
<ul>
<li><b>Inlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SINK</a>): Inlet drainage.</li>
<li><b>Outlet</b> (<a href=""../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm"">DRAINAGE</a>, <a href=""../../ifcsharedbldgserviceelements/lexical/ifcflowdirectionenum.htm"">SOURCE</a>): Outlet drainage.</li>
</ul>

"
3742;IfcClassification;"<EPM-HTML> 
<p>An <i>IfcClassification</i> is used for the arrangement of objects into a class or category according to a common purpose or their possession of common
characteristics. A classification in the sense of <i>IfcClassification</i> is taxonomy, or taxonomic scheme, arranged in a hierarchical structure. A category of objects relates to other categories in a generalization-specialization relationship. Therefore the classification items in an
classification are organized in a tree structure.</p>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.5. Modified in IFC 2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC 2x4 CHANGE Attribute <i>Edition</i> made optional. Attributes: <i>PublicationLocation</i>, <i>Description</i> and <i>ReferenceTokens</i> added. Inverse attribute <i>HasClassificationReferences</i> added.
</blockquote>

<p class=""head-use"">Classification use definitions</p>
<p><i>IfcClassification</i> identifies the classification system or source from which a classification notation is derived. Each classification reference or classification item, belonging to a single classification system, shall reference a single instance of <i>IfcClassification</i>. Therefore, each particular classification system or source used should have only one <i>IfcClassification</i> instance. However, because multiple classification is allowed, there may be many <i>IfcClassification</i> objects used, each identifying a different classification system or source.</p>

<p>A classification system declared may be either formally published (such as Omniclass, Uniclass, Masterformat, or DIN) or it may be a locally defined method of classifiying information.  There are two methods to define a classification system within an IFC dataset:</p>
<ol>
<li>Including the classification system structure within the dataset: Here a hierarchical tree of <i>IfcClassificationItem</i>'s is included that defines the classification system including the relationship between the classification items. An <i>IfcClassificationNotation</i> is used to classify an object.</li>
<li>Referencing the classification system by a classification key or id: Here the <i>IfcClassificationReference</i> is used to assign a classification id or key to each classified object.</li>
</ol>

</EPM-HTML>"
3752;IfcExternalInformation;"<EPM-HTML>

<p>An <i>IfcExternalInformation</i> is the identification of an information source that is not explicitly represented in the current model or in the project database (as an implementation of the current model). The <i>IfcExternalInformation</i> identifies the external source (classification, document, or library), but not the particular items such as a dictionary entry, a classification notation, or a document reference within the external source</p>

<p>The <i>IfcExternalInformation</i> is an abstract supertype of
all external information entities.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
3756;IfcLibraryInformation;"<EPM-HTML>

<p>An <i>IfcLibraryInformation</i> describes a library where a library is a structured store of information, normally organized in a manner which allows information lookup through an index or reference value. <i>IfcLibraryInformation</i> provides the library <em>Name</em> and optional <em>Version</em>, <em>VersionDate</em> and <em>Publisher</em> attributes. A <em>Location</em> may be added for electronic access to the library.</p>

<blockquote class=""note"">
NOTE&nbsp; The complete definition of the information in an external library is out of scope in this IFC release.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New
Entity in IFC2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; <em>Location</em> attribute added, <em>HasLibraryReferences</em> inverse attribute added (previous LibraryReference changed to inverse).
</blockquote>

</EPM-HTML>"
3765;IfcLibraryReference;"<EPM-HTML> 

<p>An <em>IfcLibraryReference</em> is a reference into a library of information by <em>Location</em> (provided as a URI). It also provides an optional inherited <em>Identification</em> key to allow more specific references to library sections or tables. The inherited <em>Name</em> attribute allows for a human interpretable identification of the library item. Also, general information on the library from which the reference is taken, is given by the <em>ReferencedLibrary</em> relation which identifies the relevant occurrence of <em>IfcLibraryInformation</em>.</p>

<p>The <em>ifcLibraryReference</em> additionally provides the capability to handle multilingual library entries. The <em>Language</em> attribute then holds the language tag for the language used by the strings kept in the <em>Name</em> and the <em>Description</em> attribute.</p>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2.0.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; <em>Description</em> and <em>Language</em> attribute added; <em>ReferencedLibrary</em> attribute added (reversing previous ReferenceIntoLibrary inverse relationship).
</blockquote>

</EPM-HTML>"
3770;IfcExternalReference;"<EPM-HTML> 

<p>An <i>IfcExternalReference</i> is the identification of information that is not explicitly represented in the current model or in the project database (as an implementation of the current model). Such information may be contained in classifications, documents or libraries. The <i>IfcExternalReference</i> identifies a particular item, such as a
dictionary entry, a classification notation, or a document reference within the external source.</p>

<p>Only the <i>Location</i> (as a URL) is given to describe the place where the information can be found. Also an optional
<i>Identification</i> as a key to allow more specific references (as to sections or tables) is provided. The <i>Identification</i> defines a system interpretable method to identify the relevant part of information at the source. In addition a human interpretable <i>Name</i> can be assigned to identify the information subject, such as a classification code.</p>

<p><i>IfcExternalReference</i> is an abstract supertype of all external reference entities.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x.
</blockquote>

</EPM-HTML>"
3779;IfcClassificationReference;"<EPM-HTML> 
<p>An <i>IfcClassificationReference</i> is a reference into a classification system or source (see <i>IfcClassification</i>) for a specific classification key (or notation).</p>

<p>The inherited attributes have the following meaning:</p>
<ul>
<li><i>Identification</i>: holds the key provided for a specific references to classification items (or tables).</li>
<li><i>Name</i>: allows for a human interpretable designation of a classification notation.</li>
<li><i>Location</i>: optionally holds a direct URI link into the classification system (or source) to hyperlink the classification key.</li>
</ul>

<p>The <i>IfcClassificationReference</i> can either be assigned directly to the <i>IfcClassification</i>, such as if no classification hierarchy has to be included, or it references the parent classification notation, if the fully classification hierarchy is included in the data set. The attribute <i>ReferencedSource</i> then holds the following information (choice by <i>IfcClassificationReferenceSelect</i>):</p>
<ul>
<li>being of type <i>IfcClassification</i>: direct reference to the classification system (with meta information provided), used for highest level of classification notations, or if the classification notation hierarchy is not relevant,</li>
<li>being of type <i>IfcClassificationReference</i>: reference to the parent classification notation within the classification hierarchy.</li>
</ul>

<blockquote class=""history"">
HISTORY New entity in IFC 2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The attribute <i>Description</i> and inverse attribute <i>HasReferences</i> are added.  The attribute <i>Identification</i> has been renamed from ItemReference.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p>The <i>IfcClassificationReference</i> can be used to only assign classification keys to objects, or to hold a fully classification hierarchy. The first is refered to as ""lightweight classification"", and the second as ""full classification""</p>

<p>The <i>IfcClassificationReference</i> can be used as a form of 'lightweight' classification through the '<i>Identification</i>' attribute inherited from the abstract <i>IfcExternalReference</i> class. In this case, the '<i>Identification</i>' could take (for instance) the Uniclass notation ""L6814"" which, if the classification was well understood by all parties and was known to be taken from a particular classification source, would be sufficient. The <i>Name</i> attribute could be the title ""Tanking"". This would remove the need for the overhead of the more complete classification structure of the model.</p>

</EPM-HTML>"
3787;IfcDocumentReference;"<EPM-HTML> 


<p>An <i>IfcDocumentReference</i> is a reference 
to the location of a document. The reference is given by a system 
interpretable <i>Location</i> attribute (a URL string) where the document can be found, and an optional inherited
 internal reference <i>Identification</i>, which refers to a system
 interpretable position within the document. The optional inherited
<i>Name</i> attribute is meant to have meaning for human readers. Optional 
document metadata can also be captured through reference to 
<i>IfcDocumentInformation</i>.</p>



<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0.
  Modified in IFC 2x.
</blockquote>





</EPM-HTML>"
3792;IfcDocumentInformation;"<EPM-HTML> 

<p><I>IfcDocumentInformation</I> captures ""metadata"" of an external document. The actual content of the document is not defined in IFC; instead, it can be found following the reference given to <i>IfcDocumentReference</i>.</p> 

<blockquote class=""history"">
HISTORY: New entity in IFC 2x.
</blockquote>

</EPM-HTML>"
3814;IfcDocumentElectronicFormat;"<EPM-HTML> 

<p><i>IfcDocumentElectronicFormat</i> captures the type of document being referenced as an external source, and for which metadata is specified by <i>IfcDocumentInformation</i>.</p> 

<blockquote class=""history"">
HISTORY: New entity in IFC 2x
</blockquote> 

</EPM-HTML>"
3832;IfcDocumentInformationRelationship;"<EPM-HTML> 
<p>An <i>IfcDocumentInformationRelationship</i> is a relationship class that enables a document to have the ability to reference other documents.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC2x.
</blockquote>
<blockquote>
IFC2x4 CHANGE&nbsp; Subtyped from <em>IfcResourceLevelRelationship</em>, order of attributes changed.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p>This class can be used to describe relationships in which one document may reference one or more other sub documents or where a document is used as a replacement for another document (but where both the original and the replacing document need to be retained).</p>

</EPM-HTML>"
3836;IfcResourceLevelRelationship;"<EPM-HTML>

<p><i>IfcResourceLevelRelationship</i> is an abstract base class for relationships between resource-level entities.</p>

<blockquote class=""history"">
HISTORY New Entity in IFC 2x4
</blockquote>

</EPM-HTML>"
3849;IfcExternalReferenceRelationship;"<EPM-HTML>

<p><em>IfcExternalReferenceRelationship</em> is a relationship entity that enables objects from the
<em>IfcResourceObjectSelect</em> to have the ability to be tagged by external references.</p>

<blockquote class=""note"">
NOTE This relationship is used to assign classification, library or document information to entities that
do not inherit from <i>IfcRoot</i>. It has a similar functionality as the subtypes of <i>IfcRelAssociates</i>.
</blockquote>

<blockquote class=""history"">
HISTORY New Entity in IFC 2x4
</blockquote>

</EPM-HTML>"
3877;IfcConstraint;"<EPM-HTML> 
<p>An <i>IfcConstraint</i> is used to define a constraint or limiting value or boundary condition that may be applied to an object or to the value of a property. </p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0
</blockquote> 

<h3>Use Definition</h3> 
<p><i>IfcConstraint</i> may be associated with any subtype of <i>IfcRoot</i> (unless restricted in specific subtypes) through the <i>IfcRelAssociatesConstraint</i> relationship in the <i>IfcControlExtension</i> schema, or may be associated with <i>IfcProperty</i> by <i>IfcPropertyConstraintRelationship</i>.</p> 

<p>A constraint may aggregate other constraints through the <i>IfcConstraintAggregationRelationship</i> through which a logical association between constraints may be applied, or constraints may have other defined relationship to other constraints via <I>IfcConstraintRelationship</i>.</p> 

<p>A constraint must have a name applied through the <i>IfcConstraint.Name</i> attribute and optionally, a description through <i>IfcConstraint.Description</i>. The grade of the constraint (hard, soft, advisory) must be specified through <i>IfcConstraint.ConstraintGrade</i> or <i>IfcConstraint.UserDefinedGrade</i> whilst the source, creating actor and time at which the constraint is created may be optionally asserted through <i>IfcConstraint.ConstraintSource</i>, <i>IfcConstraint.CreatingActor</i> and <i>IfcConstraint.CreationTime</i>.</p> 

<p>A constraint may also have additional external information (such as classification or document information) associated to it by <i>IfcExternalReferenceRelationship</i>, accessible through inverse attribute <i>IfcConstraint.HasExternalReferences</i></p>

</EPM-HTML>"
3893;IfcObjective;"<EPM-HTML> 

<p>An <i>IfcObjective</i> captures qualitative information for an objective-based constraint.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0
</blockquote> 

<h3>Use definition</h3> 

<p><i>IfcObjective</i> is a subtype of <i>IfcConstraint</i> and may be associated with any subtype of <i>IfcRoot</i> through the <i>IfcRelAssociatesConstraint</i> relationship in the <i>IfcControlExtension</i> schema, or may be associated with <i>IfcProperty</i> by <I>IfcPropertyConstraintRelationship</i>.</p>

<p>The aim of <i>IfcObjective</i> is to specify the purpose for which the constraint is applied and to capture the values of the constraint. These may be both the benchmark values that are intended to indicate the constraint extent and the resulting values in use that enable performance comparisons to be applied.</p> 

</EPM-HTML>"
3899;IfcMetric;"<EPM-HTML> 

<p>An <i>IfcMetric</i> is used to capture quantitative resultant metrics that can be applied to objectives.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 2.0
</blockquote>
 
<h3>Use Definition</h3> 
<p><i>IfcMetric</i> is a subtype of <I>IfcConstraint</I> and may be associated with any subtype of <i>IfcRoot</i> through the <i>IfcRelAssociatesConstraint</i> relationship in the <i>IfcControlExtension</i> schema, or may be associated with <i>IfcProperty</i> by <i>IfcPropertyConstraintRelationship</i>.</p> 

<p>The aim of <i>IfcMetric</i> is to capture the quantitative aspects of a constraint.</p> 

<p>For instance, when undertaking a move (instantiated through the <i>IfcTask</i> class), a constraint is instantiated as the class <i>IfcMetric</i> and may be named as a 'Move Start Constraint' or 'Move End Constraint' and described using one of a possible range of move constraints as shown in the table below.</p> 

	 <table border=""1""> 
		<tr> 
		  <td><i>Constraint</i></td> 
		  <td width=""440""><i> Description</i></td> 
		  <td width=""270""><i> Benchmark</i></td> 
		  <td width=""100""><i> Grade</i></td> 
		</tr> 
		<tr> 
		  <td>ASSOONASPOSSIBLE</td> 
		  <td width=""440"">Action should commence at the earliest possible opportunity.</td> 
		  <td width=""270"">GREATERTHANOREQUALTO</td> 
		  <td width=""100"">SOFT</td> 
		</tr> 
		<tr> 
		  <td>MUSTSTARTON</td> 
		  <td width=""440"">Action must start at a prescribed date/time.</td> 
		  <td width=""270"">EQUALTO</td> 
		  <td width=""100"">HARD</td> 
		</tr> 
		<tr> 
		  <td>MUSTSTARTBEFORE</td> 
		  <td width=""440"">Action must start before a prescribed date/time.</td> 
		  <td width=""270"">LESSTHANOREQUALTO</td> 
		  <td width=""100"">HARD</td> 
		</tr> 
		<tr> 
		  <td>MUSTSTARTAFTER</td> 
		  <td width=""440"">Action must not start before a prescribed date/time.</td> 
		  <td width=""270"">GREATERTHANOREQUALTO</td> 
		  <td width=""100"">HARD</td> 
		</tr> 
		<tr> 
		  <td>MAYSTARTAFTER</td> 
		  <td width=""440"">Action may start at any time following a prescribed date/time.</td> 
		  <td width=""270"">GREATERTHANOREQUALTO</td> 
		  <td width=""100"">SOFT</td> 
		</tr> 
		<tr> 
		  <td>MUSTFINISHON</td> 
		  <td width=""440"">Action must be complete at or by a prescribed date/time.</td> 
		  <td width=""270"">EQUALTO</td> 
		  <td width=""100"">HARD</td> 
		</tr> 
		<tr> 
		  <td>MUSTFINISHBEFORE</td> 
		  <td width=""440"">Action must be complete before a prescribed date/time.</td> 
		  <td width=""270"">LESSTHANOREQUALTO</td> 
		  <td width=""100"">HARD</td> 
		</tr> 
	 </table> 

<p>This constraint (instantiated as <i>IfcMetric</i>) uses a Date/Time value in <i>IfcMetric.DataValue</i> through <i>IfcMetricValueSelect</i>. An appropriate benchmark is applied according to the requirement of the constraint (as indicated) by <i>IfcMetric.Benchmark</i>. The grade of the constraint (hard, soft, advisory) must be specified through		<i>IfcConstraint.ConstraintGrade</i> whilst the time at which the constraint is	created may be optionally asserted through <i>IfcConstraint.CreationTime</i>.</p>

</EPM-HTML>"
3937;IfcResourceConstraintRelationship;"<EPM-HTML> 

<p>An <i>IfcResourceConstraintRelationship</i> is a relationship
entity that enables a constraint to be related to one or more
resource level objects.</p>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in Release IFC2x2.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Renamed from IfcPropertyConstraintRelationship and extended to apply to all resource level entities.  Subtyped from <em>IfcResourceLevelRelationship</em>.
</blockquote>

<p class=""use-head"">Use definition</p>

<p>An <i>IfcResourceConstraintRelationship</i> allows for the
specification of a constraint to be applied to many entity types.
An important case is to apply constraints to properties. The
constraints applied therefore enable a property to carry values
identifying requirements as well as those identifying the
fulfilment of those requirements.</p>

<p>Figure 238 shows how a constraint may be applied to a property within a property set. For simplicity, only the mandatory attributes are shown as asserted. It shows how a property 'ThingWeight' which has a nominal value of 19.5 kg has two constraints that are logically aggregated by an AND connection. One of the constraints has a benchmark of 'GREATERTHANOREQUALTO' whilst the second has a benchmark of 'LESSTHANOREQUALTO'. This means that the constraint must lie between these two bounding values. The relating constraint is instantiated as an objective named as 'Weight Constraint' and qualified as a SPECIFICATION constraint. The two related constraints are both specified as metrics since they can have specific values.</p>

<table summary=""constraint of properties"">
<tr valign=""top""><td><img src=""figures/IfcResourceConstraintRelationship_fig-1.png"" alt=""Constraint usage for properties"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 238 &mdash; Resource constraint relationship</p></td></tr>
</table>

</EPM-HTML>"
3940;IfcConstraintRelationship;"<EPM-HTML>
<p>An <i>IfcConstraintRelationship</i> is an objectified relationship that enables instances of <i>IfcConstraint</i> and its
subtypes to be associated to each other. Logical aggregation of instances of <i>IfcConstraint</i> and its subtypes is handled by the subtype <i>IfcConstraintAggregationRelationship</i>.</p>

<blockquote class=""example"">
EXAMPLE: Certain constraints related to an <i>IfcWall</i> may be derived from a constraint related to an
<i>IfcSpace</i>.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC2x2 (Addendum 1).
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Subtyped from <em>IfcResourceLevelRelationship</em>.
</blockquote>

</EPM-HTML>"
3945;IfcConstraintAggregationRelationship;"<EPM-HTML> 

<p>An <I>IfcConstraintAggregationRelationship</I> is an objectified relationship that enables instances of <I>IfcConstraint</I> subtypes to be aggregated together logically.</p> 

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC Release 2.0. Modified in IFC2x2.
</blockquote> 
<blockquote class=""change-ifc2x4""> 
IFC2x4 CHANGE&nbsp; Subtyped from <I>IfcConstraintRelationship</I>
</blockquote>

<h3>Use definition</h3> 
<p><I>IfcConstraintAggregationRelationship</I> allows the aggregation link between subtypes of constraint to be logically defined (AND, OR, XOR, NOTAND, NOTOR). In this way, whereby an object or property can have multiple constraints assigned, and the logical linkage between them can be specified. Thus linked constraints might show as for example (&gt; X AND &lt; Y) which is useful for an allowed range, or bounded value, for example, (A OR B OR C) which is valuable for an enumerated property where a selection is constrained to be (at least) one of A, B or C.</p> 
<p>Figure 237 illustrates constraint aggregation.</p>

<table>
<tr><td><img src=""figures/ConstraintAggregation.png"" alt=""ConstraintAggregation"" width=""665"" height=""492"" border=""0"" align=""middle""></td></tr>
<tr><td><p class=""figure"">Figure 237 &mdash; Constraint aggregation</p></td></tr>
</table>

</EPM-HTML>"
3954;IfcCostValue;"<EPM-HTML> 

<p><i>IfcCostValue</i> is an amount of money or a value that affects an amount of money.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC Release 1.0
</blockquote> 
	 
<p class=""head-use"">Use definitions</P> 
<p>Each instance of <i>IfcCostValue</i> may also have a <i>CostType</i>. There are many possible types of cost value that may be identified. While there is a broad understanding of the meaning of names that may be assigned to different types of costs, there is no general standard for naming cost types nor are there any broadly defined classifications. To allow for any type of cost value, the <i>IfcLabel</i> datatype is assigned.</p>

<p>The following defines some cost types that might be applied: </p> 
<ul>
<li>Annual rate of return</li>
<li>Bonus</li>
<li>Bulk purchase rebate</li>
<li>Contract</li>
<li>Consultancy</li>
<li>Delivery</li>
<li>Estimated cost</li>
<li>Hire</li>
<li>Installation</li>
<li>Interest rate</li>
<li>Labor</li>
<li>Lease</li>
<li>List price</li>
<li>Maintenance</li>
<li>Material</li>
<li>Overhead</li>
<li>Postage and packing</li>
<li>Profit</li>
<li>Purchase</li> 
<li>Rental</li>
<li>Repair</li>
<li>Replacement</li>
<li>Sale</li>
<li>Small quantity surcharge</li>
<li>Spares</li>
<li>Storage</li>
<li>Sub-Contract</li>
<li>Trade discount</li>
<li>Transportation</li>
<li>Waste allowance</li>
<li>Whole life</li>
</ul>

<p>In the absence of any well-defined standard, it is recommended that local agreements should be made to define allowable and understandable cost value types within a project or region.</p> 

</EPM-HTML>"
3957;IfcAppliedValue;"<EPM-HTML> 

<p><i>IfcAppliedValue</i> is an abstract supertype that specifies the common attributes for cost values.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC2x2.  Modifed in IFC2x4 to use <i>IfcDate</i> for date values.
</blockquote> 

<p class=""head-use"">Use definitions</P> 
<p>The extent of the <I>IfcAppliedValue</I> is determined by the <I>AppliedValue</I> attribute which may be defined either as an <I>IfcMeasureWithUnit</I> or as an <I>IfcMonetaryMeasure</I> or as an <I>IfcRatioMeasure</I> via the <I>IfcAppliedValueSelect</I> type. </p> 

<p>Optionally, an <I>IfcAppliedValue</I> may have an applicable date. This is intended to fix the date on which the value became relevant for use. It may be the date on which the value was set in the model or it may be a prior or future date when the value becomes operable.</p>

<p>Similarly, an <I>IfcAppliedValue</I> may have a 'fixed until' date. This is intended to fix the date on which the value ceases to be relevant for use.</p> 

<p>An instance of <I>IfcAppliedValue</I> may have a unit basis asserted.  This is defined as an <I>IfcMeasureWithUnit</I> that determines the extent of the unit value for application purposes. It is assumed that when this attribute is asserted, then the value given to <I>IfcAppliedValue</I> is that for unit quantity. This is not enforced within the IFC schema and thus needs to be controlled within an application.</p>

<p>Applied values may be referenced from a document (such as a price list). The relationship between one or more occurrences of <i>IfcAppliedValue</i> (or its subtypes) is achieved through the use of the <i>IfcExternalReferenceRelationship</i> in which the document provides the <i>IfcExternalReferenceRelationship.RelatingExtReference</i> and the value occurrences are the <i>IfcExternalReferenceRelationship.RelatedResourceObjects</i>.</p>

</EPM-HTML>"
3973;IfcCurrencyRelationship;"<EPM-HTML> 

<p><i>IfcCurrencyRelationship</i> defines the rate of exchange
that applies between two designated currencies at a particular time
and as published by a particular source.</p>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2x2.</span>
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Subtyped from <em>IfcResourceLevelRelationship</em>, attribute order changed.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p>An <i>IfcCurrencyRelationship</i> is used where there may be a need to reference an <i>IfcCostValue</i> in one currency to an <i>IfcCostValue</i> in another currency. It takes account of fact that currency exchange rates may vary by requiring the recording the date and time of the currency exchange rate used and the source that publishes the rate. There may be many sources and there are different strategies for currency conversion (spot rate, forward buying of currency at a fixed rate).</p>
<p>The source for the currency exchange is defined as an instance of <i>IfcLibraryInformation</i> that includes a name and a URL.</p>

</EPM-HTML>"
3979;IfcAppliedValueRelationship;"<EPM-HTML> 

<p>An <i>IfcAppliedValueRelationship</i> is a relationship class that enables cost values to be aggregated together as components of another cost value.</p>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in Release IFC2.0.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Subtyped from <i>IfcResourceLevelRelationship</i>, attribute order changed.
</blockquote>

<p class=""use-head"">Use definitions</p>
<p>Dependency relationships can exist between applied values on the basis that one particular value may be determined by operations on one or more other values. This is captured through the <i>IfcAppliedValueRelationship</i> entity. In this relationship, one instance of <i>IfcAppliedValue</i> acts as the principal (<i>IfcAppliedValueRelationship.ComponentOf</i>) whose value may be
determined from the instances of <i>IfcAppliedValue</i> that are defined as its components
(<i>IfcAppliedValueRelationship.Components</i>)</p>
<p>An <i>IfcAppliedValueRelationship</i> has an <i>ArithmeticOperator</i> attribute that specifies the form of arithmetical operation implied by the relationship.</p>
<p>A practical consideration when using the applied value relationship is that when the arithmetic operator is ADD, then the
type of the <i>IfcAppliedValue.AppliedValue</i> attribute will be <i>IfcMeasureWithUnit</i> or <i>IfcMonetaryMeasure</i> while if the arithmetic operator is MULTIPLY, then the type of the <i>IfcAppliedValue.AppliedValue</i> attribute for one instance of
<i>IfcAppliedValue</i> will be <i>IfcMeasureWithUnit</i> or <i>IfcMonetaryMeasure</i> while for other instances it will be
<i>IfcRatioMeasure</i>.</p>
<p>If the arithmetic operator is SUBTRACT or DIVIDE then there can only be two occurrences of IfcAppliedValue that can contribute and the order in which they occur is significant. The value of (A - B) will usually differ from the value of (B - A) whilst (X / Y) is the reciprocal of (Y / X).</p>

<p>Figure 239 illustrates one level aggregation of applied values. A relationship exists between applied value A and applied values B, C and D such that the value of A is determined by the addition of B, C and D such that: A = B + C + D</p>

<table summary=""cost relationship"">
<tr valign=""top""><td><img src=""figures/IfcAppliedValueRelationship_Fig-1.png"" alt=""Adding Applied Values"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 239 &mdash; Applied value relationship single level</p></td></tr>
</table>

<p>Figure 240 illustrates two level aggregation of applied values. It is possible to develop more complex applied value specifications by creating hierarchies of applied value relationships. In the diagram, the development of a applied value is shown whereby, because B = E * F and D = G * H * J, then: A = ((E * F) + C + (G * H * J)).</p>

<table summary=""cost relationship"">
<tr><td><img src=""figures/IfcAppliedValueRelationship_Fig-2.png"" alt=""Multiply Applied Values"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 240 &mdash; Applied value relationship multiple level</p></td></tr>
</table>

</EPM-HTML>"
3989;IfcResourceCost;"<EPM-HTML> 

<p><i>IfcResourceCost</i> defines cost information for resources.</p> 

<blockquote class=""history"">
HISTORY: New Entity in IFC 2x4.
</blockquote>

</EPM-HTML>"
4005;IfcTimeSeries;"<epm-html>

<p>A time series is a set of a time-stamped data entries. It allows a natural association of data collected over intervals of time. Time series can be regular or irregular. In regular time series data arrive predictably at predefined intervals.  In irregular time series  some or all time stamps do not follow a repetitive pattern and unpredictable bursts of data may arrive at unspecified points in time.</p>

<p>The modeling of buildings and their performance involves data that are generated and recorded over a period of time.  Such data cover a large spectrum, from weather data to schedules of all kinds to status measurements to reporting to everything else that has a time related aspect. Their correct placement in time is essential for their proper understanding and use, and the <i>IfcTimeSeries</i> subtypes provide the appropriate data structures to accommodate these types of data.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC 2x2.
</blockquote>

</epm-html>"
4017;IfcRegularTimeSeries;"<epm-html>

<p>In a regular time series, the data arrives predictably at predefined intervals. In a regular time series there is no need to store multiple time stamps and the algorithms for analyzing the time series are therefore significantly simpler.  Using the start time provided in the supertype, the time step is used to identify the frequency of the occurrences of the list of values.</p>

<blockquote class=""example"">
EXAMPLE: A smoke detector samples the concentration of particulates in a space at a fixed rate (for example, every six seconds); a control system measures the outside air temperature every hour.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC 2x2.
</blockquote>

</epm-html>
"
4020;IfcTimeSeriesValue;"<epm-html>

<p>A time series value is a list of values that comprise the time series. At least one value must be supplied. Applications are expected to normalize values by applying the following three rules:</p>
<ul>
<li>All time (universal, local, daylight savings, and solar) is normalized against the ISO 8601 standard GMT/UTC (Universal Coordinated Time).</li>
<li>Any rollover is handled by the application providing the data.  Rollover occurs, for example, when the measurement device resets itself while measuring and the recording data do not include the data measured before the reset.</li>
<li>The normalized data refer to the preceding time unit.  The time series example shown in Figure 241 below contains four time points: Time ""a"" indicates the beginning of the time series and the associated datum has no relevance.  Data at time points ""b,"" ""c"" and ""d"" are associated with values 1, 2 and 3, respectively.</li>
</ul>

<table> 
<tr><td valign=""top"" align=""left""><img src=""figures/IfcTimeSeries_TimeSeriesValue.gif"" alt=""time series values"" width=""575"" height=""95"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 241 &mdash; Time series value</p></td></tr> 
</table> 

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</epm-html>"
4022;IfcIrregularTimeSeries;"<epm-html>

<p>In an irregular time series, unpredictable bursts of data arrive at unspecified points in time, or most time stamps cannot be characterized by a repeating pattern.</p>

<blockquote class=""example"">
EXAMPLE: A circulating pump cycles on and off at unpredictable times as dictated by the demands on the piping system; the amount of light in a classroom varies depending on when the lights are manually switched on and off and and how many lamps are controlled by each switch.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC 2x2.
</blockquote>

</epm-html>
"
4024;IfcIrregularTimeSeriesValue;"<epm-html>

<p>The <i>IfcIrregularTimeSeriesValue</i> describes a value (or set of values) at a particular time point.</p> 

<blockquote class=""history""> 
HISTORY: New entity in IFC 2x2.
</blockquote>

</epm-html>"
4041;IfcTaskTime;"<epm-html> 

<p><i>IfcTaskTime</i> captures the time-related information about a task including the different types (actual or scheduled) of starting and ending times.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x4, adapted from <i>IfcScheduleTimeControl</i>.  Differently to <i>IfcScheduleTimeControl</i> it is also possible to differentiate duration time measures between the two possible types; (1) work time and (2) elapsed time.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p>All given values should be provided by the application; the IFC schema does not deal with dependencies between task time values. There is also no consistency check through where rules that guarantee a meaningful population of time values. Thus, an application is responsible to provide reasonable values and, if an application receives task times, has to make consistency checks by their own.</p>

<p><i>IfcTaskTime</i> furthermore provides a generic mechanism to differentiate between user given time values and time values derived from user given time values and other constraints such as work calendars and assigned resources.</p>

</epm-html>"
4060;IfcSchedulingTime;"<epm-html> 

<p><i>IfcSchedulingTime</i> is the abstract supertype of entities that capture time-related information of processes.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x4.
</blockquote>

</epm-html>"
4069;IfcLagTime;"<epm-html>

<p><i>IfcLagTime</i> describes the time parameters that may exist within a sequence relationship between two processes.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x4.
</blockquote>

<p class=""head-use"">Use Definitions</p>
    <p>
      An <i>IfcLagTime</i> provides information about the
      time lag that exists between the predecessor and successor
      process in a sequence. The assertion of the time lag is
      optional for a sequence but for work schedules that
      specifically deal with processes occurring at particular
      times, it should be asserted.
    </p>
    <p>
      A lag time has a duration type. This allows the
      identification of whether elapsed time or work time is
      being measured (where work time is the estimate of the time
      required to complete the process and elapsed time being the
      amount of time actually allocated to the process)
    </p>
    <p>
      The form of measurement of the duration can be captured.
      Allowed values for this are MEASURED, PREDICTED or
      SIMULATED. The selection of this value depends on the use
      of the schedule. A NOTDEFINED value is also allowed.
    </p>
    <p>
      The value of the time lag may be selected as being either a
      percentage ratio or an actual time measure. If selected as
      a ratio, the percentage should apply to the duration of the
      predecessor process (relating process) such that e.g. a
      value of 0.5 (50%) would indicate that the successor task
      should start when the predecessor task is 50% complete (if
      a START-START sequence type is used) or should wait for 50%
      of the duration of the predecessor process to have elapsed
      after the finish of the predecessor process in case of a
      FINISH-START sequence type.
    </p>
    <p>
      The time unit for the task duration may also be set and
      this may be set to any allowed unit of time measure.
    </p>

</epm-html>"
4079;IfcResourceTime;"<epm-html>
    <p><i>IfcResourceTime</i> captures the time-related information about a construction resource.</p>
    <blockquote class=""history"">HISTORY: New entity in IFC2x4.</blockquote>
</epm-html>"
4095;IfcEventTime;"<epm-html> 
    <p>
      <i>IfcEventTime</i> captures the time-related information about an event
      including the different types of event dates (i.e. actual,
      scheduled, early, and late).
    </p>
    <blockquote class=""history"">HISTORY: New entity in IFC2x4.</blockquote>
    <p class=""head-use"">Use definitions</p>
    <p>
      All given values should be provided by the application,
      i.e. the IFC schema does not deal with dependencies between
      process time values. At this stage there is also no
      consistency check through where rules that guarantee a
      meaningful population of date values. Thus, an application
      is responsible to provide reasonable values and, if an
      application receives event dates, has to make consistency
      checks by their own.
    </p>
    <p>
      <i>IfcEventTime</i> furthermore provides a generic
      mechanism to differentiate between user given time values
      and time values derived from user given time values and
      other constraints such as work calendars and assigned
      resources (derived from the process graph). The data origin flag 
      is provided as a single attribute applying to all date time related attributes 
      of <i>IfcEventTime</i>.
    </p>
</epm-html>"
4100;IfcWorkTime;"<epm-html>

<p><i>IfcWorkTime</i> defines time periods that are used by <i>IfcWorkCalendar</i> for either describing working times or non-working exception times. Besides start and finish dates, a set of time periods can be given by various types of recurrence patterns.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x4.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p>A work time should have a meaningful name that describes the time periods (for example, working week, holiday name). Non-recurring time periods should have a start date (<i>IfcWorkTime.Start</i>) and a finish date (<i>IfcWorkTime.Finish</i>). In that case it is assumed that the time period begins at 0:00 on the start date and ends at 24:00 on the finish date.</p>

<p>The start and finish date is optional if a recurrence pattern is given (<i>IfcWorkTime.RecurrencePattern</i>).  They then restrict never-ending recurrence patterns.</p>

</epm-html>

"
4104;IfcRecurrencePattern;"<epm-html>

<p><i>IfcRecurrencePattern</i> defines repetitive time periods on the basis of regular recurrences such as each Monday in a week, or every third Tuesday in a month.  The population of the remaining attributes such as <i>DayComponent</i>, <i>Position</i>, and <i>Interval</i> depend on the specified recurrence type.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC2x4.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p><i>IfcRecurrencePattern</i> supports various recurrence patterns that are differentiated by a type definition (<i>IfcRecurrencePattern.RecurrenceType</i>), which is required to provide the meaning of the given values. It can be further constrained by applicable times through specified <i>IfcTimePeriod</i> instances, thus enabling time periods such as between 7:00 and 12:00 and between 13:00 and 17:00 for each of the applicable days, weeks or months.</p>

</epm-html>"
4128;IfcTimePeriod;"<epm-html>

<p><i>IfcTimePeriod</i> defines a time period given by a start and end time. Both time definitions consider the time zone and allow for the daylight savings offset.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC R2x4.
</blockquote>

<p class=""head-use"">Use definitions</p>
<p>A time period is defined by a start and an end time, which is defined by <i>IfcTime</i>. The given time period should be within reasonable values (for example, the start time must be before the end time). It is furthermore expected that both time definitions use the same time zone and, if given, the same daylight saving offset.</p>

</epm-html>"
4131;IfcTaskTimeRecurring;"<epm-html> 

<p><i>IfcTaskTimeRecurring</i> is a recurring instance of <i>IfcTaskTime</i> for handling regularly scheduled or repetitive tasks.</p>

<blockquote class=""history"">HISTORY: New entity in IFC2x4.</blockquote>

</epm-html>"
4134;IfcConnectionGeometry;"<EPM-HTML> 

<p><i>IfcConnectionGeometry</i> is used to describe the geometric and topological constraints that facilitate the physical connection of two objects. It is envisioned as a control that applies to the element connection relationships.</p>

<blockquote class=""note"">
NOTE&nbsp; The element connection relationship normally provides for a logical connection information, by referencing the relating and related elements. If in addition an <i>IfcConnectionGeometry</i> is provided, physical connection information is given by specifying exactly where at the relating and related element the element connection occurs. 
Using the eccentricity subtypes, the connection can also be described when there is a physical distance (or eccentricity) between the connection elements.
</blockquote>

<p>The <i>IfcConnectionGeometry</i> allows for the provision of connection constraints between geometric and topological elements, the following connection geometry/topology types are in scope:</p>
<ul>
  <li>point | vertex point,</li>
  <li>curve | edge curve,</li>
  <li>surface | face surface,</li>
</ul>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x Edition 3 CHANGE&nbsp; The definition of the subtypes has been enhanced by allowing either geometric representation items (point | curve | surface) or topological representation items with associated geometry (vertex point | edge curve | face &nbsp;surface).
</blockquote>

</EPM-HTML>"
4139;IfcConnectionPointGeometry;"<EPM-HTML> 
<p><i>IfcConnectionPointGeometry</i>
is used to describe the geometric constraints that facilitate the
physical connection of two objects at a point (here <i>IfcCartesianPoint</i>) or at an vertex with point
coordinates associated. It is envisioned as a control that applies to the element connection relationships. </p>

<blockquote class=""example"">
EXAMPLE&nbsp; The connection relationship between two path based elements (like a column and a beam) has a geometric constraint which describes the connection points by a <i>PointOnRelatingElement</i> for the column and a <i>PointOnRelatedElement</i> for the beam. The exact usage of the <i>IfcConnectionPointGeometry</i> is further defined in the geometry use sections of the elements that use it.<br>
  <br>
NOTE &nbsp;If the point connection has an offset (if the two points or vertex points at the relating and related element do not physically match), the subtype <i>IfcConnectionPointEccentricity</i> shall be used.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5, has been renamed from IfcPointConnectionGeometry in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x3"">
IFC2x Edition 3 CHANGE&nbsp; The provision of topology with associated geometry, <i>IfcVertexPoint</i>, is
enabled by using the <i>IfcPointOrVertexPoint</i>.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The <i>IfcPoint</i> (or the <i>IfcVertexPoint</i> with an associated <i>IfcPoint</i>) at the <i>PointOnRelatingElement</i> attribute defines the point where the basic geometry items of the connected elements connect. The point coordinates are provided within the local coordinate system of the <i>RelatingElement</i>, as specified at the <i>IfcRelConnectsSubtype</i> that utilizes the <i>IfcConnectionPointGeometry</i>. Optionally, the same point coordinates can also be provided within the local coordinate system of the <i>RelatedElement</i> by using the <i>PointOnRelatedElement</i> attribute. If both point coordinates are not identical within a common parent coordinate system (ultimately within the world coordinate system), the subtype <i>IfcConnectionPointEccentricity</i> shall be used. </p>

</EPM-HTML>"
4143;IfcConnectionPointEccentricity;"<EPM-HTML>

<p><i>IfcConnectionPointEccentricity</i> is used to describe the geometric constraints that facilitate the physical connection of two objects at a point or vertex point with associated point coordinates. There is a physical distance, or eccentricity, etween the connection points of both object. The eccentricity can be either given by:</p>
<ul>
<li>providing the <i>PointOnRelatingElement</i> and the <i>PointOnRelatedElement</i>, where both˙point coordinates are not identical within a common parent coordinate system (latestly within the world coordinate system),</li>
<li>providing the <i>PointOnRelatingElement</i> and the three distance measures, <i>EccentricityInX</i>, <i>EccentricityInY</i>, and <i>EccentricityInZ</i> (or only <i>EccentricityInX</i>, and <i>EccentricityInY</i> if the
underlying coordinate system is two-dimensional), or</li>
<li>providing both.</li>
</ul>

<blockquote class=""note"">
NOTE˙ If both, <i>PointOnRelatedElement</i>, and <i>EccentricityInX</i>, <i>EccentricityInY</i>, (<i>EccentricityInZ</i>) are provided, the values should be consistent. In case of any non-consistency, the calculated distance between <i>PointOnRelatingElement</i> and <i>PointOnRelatedElement</i> takes precedence.
</blockquote>

<p>The explicit values for <i>EccentricityInX</i>, <i>EccentricityInY</i>, and <i>EccentricityInZ</i> are always
measured in the following direction and coordinate system (defining when the value is positive or negative):</p>
<ul>
<li>from the <i>PointOnRelatedElement</i> to <i>PointOnRelatingElement</i> within the coordinate system of the <i>RelatingElement</i>.</li>
<li>in addition: when used to specify connections in structural analysis models, the <i>IfcStructuralMember</i> is to be used as the <i>RelatingElement</i> of the relationship object utilizing <i>IfcConnectionPointEccentricity</i>, and the <i>IfcStructuralConnection</i> is the <i>RelatedElement</i>.</li>
</ul>

<blockquote class=""history"">
HISTORY˙ New entity in IFC 2x Edition 3.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The <i>IfcPoint</i> (or the <i>IfcVertexPoint</i> with an associated <i>IfcPoint</i>) at the <i>PointOnRelatingElement</i> attribute defines the point where the basic geometry items of the connected elements connects. The point coordinates are provided within the local coordinate system of the <i>RelatingElement</i>, as specified at the <i>IfcRelConnects</i> subtype that utilizes the <i>IfcConnectionPointGeometry</i>. Optionally, the same point coordinates can also be provided within the local coordinate system of the <i>RelatedElement</i> by using the <i>PointOnRelatedElement</i> attribute, otherwise the distance to the point at the RelatedElement has to be given by the three eccentricity values.</p>

</EPM-HTML>"
4150;IfcConnectionCurveGeometry;"<EPM-HTML> 

<p><i>IfcConnectionCurveGeometry</i> is used to describe the geometric constraints that facilitate the physical connection of two objects at a curve or at an edge with curve geometry associated. It is envisioned as a control that applies to the element connection relationships. </p>

<blockquote class=""example"">
EXAMPLE&nbsp; The connection relationship between two walls has a geometric constraint which describes the end caps (or cut-off of the wall ends) by a <i>CurveOnRelatingElement</i> for the first wall and a <i>CurveOnRelatedElement</i> for the second wall. The exact usage of the <i>IfcConnectionCurveGeometry</i> is further defined in the geometry use sections of the elements that use it.
</blockquote>

<p>The available geometry for the connection constraint may be further restricted to only allow straight segments by applying <i>IfcPolyline</i>
only. Such an usage constraint is provided at the object definition of the <i>IfcElement</i> subtype, utilizing the element connection by referring to the subtype of <i>IfcRelConnects</i> with the associated&nbsp;<i>IfcConnectionCurveGeometry.</i></p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5, has been renamed from IfcLineConnectionGeometry in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x3"">
IFC2x Edition 3 CHANGE&nbsp; The provision of topology with associated geometry, <i>IfcEdgeCurve</i>, is enabled by using the <i>IfcCurveOrEdgeCurve</i>.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The <i>IfcCurve</i> (or the <i>IfcEdgeCurve</i> with an associated <i>IfcCurve</i>) at the <i>CurveOnRelatingElement</i> attribute defines the curve where the basic geometry items of the connected elements connects. The curve geometry and coordinates are provided within the local coordinate system of the <i>RelatingElement</i>, as specified at the <i>IfcRelConnects </i>Subtype that utilizes the <i>IfcConnectionCurveGeometry</i>. Optionally, the same curve geometry and coordinates can also be provided within the local coordinate system of the <i>RelatedElement</i> by using the <i>CurveOnRelatedElement</i> attribute. </p>

</EPM-HTML>"
4156;IfcConnectionSurfaceGeometry;"<EPM-HTML> 

<p><i>IfcConnectionSurfaceGeometry</i> is used to describe the geometric constraints that facilitate the physical connection of two objects at a surface or at a face with surface geometry associated. It is envisioned as a control that applies to the element connection relationships. </p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x3"">
IFC2x Edition 3 CHANGE&nbsp; The provision of topology with associated geometry, <i>IfcFaceSurface</i>, is enabled by using the <i>IfcSurfaceOrFaceSurface</i>.
</blockquote>

<p class=""head-use"">Geometry use definitions</p> 
<p>The <i>IfcSurface</i> (or the <i>IfcFaceSurface</i> with an associated <i>IfcSurface</i>) at the <i>SurfaceOnRelatingElement</i> attribute defines the surface where the basic geometry items of the connected elements connects. The surface geometry and coordinates are provided within the local coordinate system of the <i>RelatingElement</i>, as specified at the <i>IfcRelConnectsSubtype</i> that utilizes the <i>IfcConnectionSurfaceGeometry</i>. Optionally, the same&nbsp;surface geometry and coordinates can also be provided within the local coordinate system of the <i>RelatedElement</i> by using the <i>SurfaceOnRelatedElement</i> attribute.</p>

</EPM-HTML>"
4163;IfcConnectionVolumeGeometry;"<EPM-HTML>

<p><i>IfcConnectionVolumeGeometry</i> is used to describe the geometric constraints that facilitate the physical connection (or overlap) of two objects at a volume defined by a solid or closed shell. It is envisioned as a control that applies to the element connection or interference relationships.</p>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x4.
</blockquote>

<p class=""head-use"">Geometry use definitions</p> 
<p>The <i>IfcSolidModel</i> (or the <i>IfcClosedShell</i>) at the <i>VolumeOnRelatingElement</i> attribute defines the volume where the basic geometry items of the interfering elements overlap. The volume geometry and coordinates are provided within the local coordinate system of the <i>RelatingElement</i>, as specified at the subtypes of the relationship <i>IfcRelConnects</i> that utilizes the <i>IfcConnectionSurfaceGeometry</i>. Optionally, the same˙volume geometry and coordinates can also be provided within the local coordinate system of the <i>RelatedElement</i> by using the <i>VolumeOnRelatedElement</i> attribute.</p>

</EPM-HTML>"
4169;IfcGridAxis;"<EPM-HTML> 

<p>An individual axis, <i>IfcGridAxis</i>, is defined in the context of a design grid.  The axis definition is based on a curve of dimensionality 2. The grid axis is positioned within the XY plane of the position coordinate system defined by the <i>IfcDesignGrid</i>.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.0
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The standard geometric representation of <i>IfcGridAxis</i> is
defined using a 2D curve entity. Grid axes are normally defined
by an offset to another axis. The <i>IfcOffsetCurve2D</i>
supports this concept.</p>
<p>Each grid axis has a sense given by the parameterization of
the curve. The attribute <i>SameSense</i> is an indicator of
whether or not the sense of the grid axis agrees with, or
opposes, that of the underlying curve.</p>
<p>As shown in Figure 242, the grid axis is defined as a 2D curve within
the xy plane of the position coordinate system. Any curve can be
used to define a grid axis, most common is the use of IfcLine for
linear grids and <i>IfcCircle</i> for radial grids.</p>
<p>Most grids are defined by a pair of axis
lists, each defined by a base grid axis and axes given by an
offset to the base axis. The use of <i>IfcOffsetCurve2D</i> as
underlying AxisCurve supports this concept.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcGridAxis-Layout1.gif"" alt=""design grid""
border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 242 &mdash; Grid axis</p></td></tr>
</table>

</EPM-HTML>"
4179;IfcVirtualGridIntersection;"<EPM-HTML> 

<p><i>IfcVirtualGridIntersection</i> defines the derived location of the intersection between two grid axes. Offset values may be given to set an offset distance to the grid axis for the calculation of the virtual grid intersection.</p>

<p>The two intersecting axes (<i>IntersectingAxes</i>) define the intersection point, which exact location (in terms of the Cartesian point representing the intersection) has to be calculated from the geometric representation of the two participating curves.</p>

<blockquote class=""note"">
NOTE The <i>IfcGrid</i> local placement, that can be provided relative to the local placement of another spatial structure element, has to be taken into account for calculating the absolute placement of the <i>IfcVirtualGridIntersection</i>. Where rules and informal rules ensure, that the <i>IntersectingAxes</i> belong to the same <i>IfcGrid</i>
</blockquote>

<p>Offset values may be given (<i>OffsetDistances</i>). If given, the position within the list of <i>OffsetDistances</i>
corresponds with the position within the list of <i>IntersectingAxes</i>. Therefore:</p>
<ul>
<li><i>OffsetDistances[1]</i> sets the offset to <i>IntersectingAxes[1]</i>,</li>
<li><i>OffsetDistances[2]</i> sets the offset to <i>IntersectingAxes[2]</i>, and</li>
<li><i>OffsetDistances[3]</i> sets the offset to the virtual intersection in direction of the orientation of the cross product
of <i>IntersectingAxes[1]</i> and the orthogonal complement of the <i>IntersectingAxes[1]</i> (which is the positive or negative
direction of the z axis of the design grid position).</li>
</ul>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5. The entity name was changed from IfcConstraintRelIntersection in IFC Release 2x.
</blockquote>

<p><u>Informal Propositions</u>:</p>
<ol>
<li>Both, <i>IntersectingAxes[1]</i> and
<i>IntersectingAxes[2]</i> shall be two <i>IfcGridAxis</i>
defined by the same <i>IfcGrid</i>.</li>
<li><i>IntersectingAxes[1]</i> and <i>IntersectingAxes[2]</i>
shall not be part of the same row of grid axes, i.e. both shall
not be within the same set of <i>IfcGrid.UAxes</i> or
<i>IfcGrid.VAxes</i> of the corresponding <i>IfcGrid</i>.</li>
</ol>
<p><b><u>Geometry use definitions</u>:</b></p>
<p>The following figures explain the usage of the <i>OffsetDistances</i> and <i>IntersectingAxes</i> attributes.</p>

<p>Figure 246 illustrates two offset distances given where the virtual intersection is defined in the xy plane of the grid axis placement.</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr valign=""top""><td align=""left"" valign=""top""><img src=
""figures/IfcVirtualGridIntersection-Layout1.gif"" alt=""2D offsets"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 246 &mdash; Virtual grid intersection with two offsets</p></td></tr>
</table>

<p>Figure 247 illustrates three offset distances given where the virtual intersection is defined by an offset (in direction of the
z-axis of the design grid placement) to the virtual intersection in the xy plane of the grid axis placement.</p>

<table cellpadding=""2"" cellspacing=""2""><tr valign=""top""><td align=""left"" valign=""top""><img src=
""figures/IfcVirtualGridIntersection-Layout2.gif"" alt=""3D offsets""
border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 247 &mdash; Virtual grid intersection with three offsets</p></td></tr>
</table>

<p>The distance of the offset curve (<i>OffsetDistances[n]</i>)
is measured from the basis curve. The distance may be positive,
negative or zero. A positive value of distance defines an offset
in the direction which is normal to the curve in the sense of an
anti-clockwise rotation through 90 degrees from the tangent
vector T at the given point. (This is in the direction of
orthogonal complement(T).) This can be reverted by the
<i>SameSense</i> attribute at <i>IfcGridAxis</i> which may switch
the sense of the <i>AxisCurve</i>.</p>
<p><i>Illustration</i></p>

<p>Figure 248 illustrates an example of a negative offset where the figure shows the side of the offset.</p>
<ul>
<li><i>IntersectingAxes[1].AxisCurve</i> is an
<i>IfcTrimmedCurve</i> with an <i>IfcCircle</i> as
<i>BasisCurve</i> and <i>SenseAgreement</i> = TRUE.</li>
<li><i>IntersectingAxes[1].SameSense</i> = TRUE.</li>
<li><i>OffsetDistances[1]</i> is a negative length measure</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td align=""left"" valign=""top"" width=""320""><img src=""figures/IfcVirtualGridIntersection-Offset1.gif"" alt=""offset direction"" border=""0"" height=""211"" width=""306""></td></tr>
<tr><td><p class=""figure"">Figure 248 &mdash; Virtual grid intersection negative offset</p></td></tr>
</table>

</EPM-HTML>"
4182;IfcGridPlacement;"<EPM-HTML> 

<p><i>IfcGridPlacement</i> provides a specialization of <i>IfcObjectPlacement</i> in which
the placement and axis direction of the object coordinate system is defined by a reference to the design grid as defined in <i>IfcGrid</i>.</p>
<p>The location of the object coordinate system is given by the attribute <i>PlacementLocation</i>. It is defined as an
<i>IfcVirtualGridIntersection</i>, that is, an intersection between two grid axes with optional offsets.</p>
<p>The axis direction of the x-axis of the object coordinate
system is given either:</p>
<ul>
<li><u><i>PlacementRefDirection</i> = NIL</u>: by the tangent of the first grid axis (<i>PlacementLocation.IntersectingAxes[1]</i>) at the virtual intersection (maybe using the offset curve, if <i>PlacementLocation.OffsetDistances</i> is given);</li>
<li><u><i>PlacementRefDirection</i> = <i>IfcDirection</i></u>: by the explicitly provided direction information;</li>
<li><u><i>PlacementRefDirection</i> = <i>IfcVirtualGridIntersection</i></u>: by the tangent between the virtual grid intersection of <i>PlacementLocation</i> and the virtual grid intersection of <i>PlacementRefDirection</i>. Offsets as potentially provided in the <i>IfcVirtualGridIntersection</i>'s of <i>PlacementLocation</i> and <i>PlacementRefDirection</i> have to be taken into account.</li>
</ul>
<p>The direction of the y-axis of the <i>IfcGridPlacement</i> is the orthogonal complement to the x-axis. The plane defined by the x and y axis shall be co-planar to the xy plane of the local placement of the <i>IfcGrid</i>.˙</p> 
<p>The direction of the z-axis is the orientation of the cross product of the x-axis and the y-axis, i.e. the z-axis of the <i>IfcGridPlacement</i> shall be co-linear to the z-axis of the local placement of the <i>IfcGrid</i>.</p>

<blockquote class=""note"">
NOTE The <i>IfcGrid</i> local placement, that can be provided relative to the local placement of another spatial structure element, has to be taken into account for calculating the absolute placement of the virtual grid intersection.
</blockquote>
<blockquote class=""note"">
NOTE The <i>PlacementLocation.OffsetDistances[3]</i> and the <i>PlacementRefDirection.OffsetDistances[3]</i> shall either not be assigned or should have the same z offset value.
</blockquote>
<blockquote class=""history"">
HISTORY ˙New entity in IFC Release 1.5. The entity name was changed from IfcConstrainedPlacement in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Attribute data type of <i>PlacementRefDirection</i> has been changed to <i>IfcGridPlacementDirectionSelect</i>.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The following examples show the usage of placement location and direction for an <i>IfcGridPlacement</i>.</p>


<p>Figure 243 illustrates the case where <i>PlacementRefDirection</i> is <u>not</u> given - the object coordinate system is defined by:</p>
<ul>
<li><u>its location</u>: given by the virtual grid intersection of <i>PlacementLocation</i></li>
<li><u>its x-axis direction</u>: given by the tangent of the first intersecting axis in the offset location of the virtual grid intersection</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"" summary=""Geometry use definition"">
<tr><td align=""left"" valign=""top""><img src=""figures/IfcGridPlacement-Layout1.png"" alt=""without ref direction"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 243 &mdash; Grid placement</p></td></tr>
</table>

<p>Figure 244 illustrates the case where <i>PlacementRefDirection</i> is given as an <i>IfcDirection</i>- the object coordinate system is defined by:
<ul>
<li><u>its location</u>: given by the virtual grid intersection of <i>PlacementLocation</i></li>
<li><u>its x-axis direction</u>: given by the <i>DirectionRatios</i> of the <i>IfcDirection</i>, only the ratios for x and y are taken into account,</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"" summary=""Geometry use definition"">
<tr><td align=""left"" valign=""top""><img src=""figures/IfcGridPlacement-Layout3.png"" alt=""with ref direction"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 244 &mdash; Grid placement with direction</p></td></tr>
</table>

<p>Figure 245 illustrates the case where <i>PlacementRefDirection</i> is given as an <i>IfcVirtualGridIntersection</i>- the object coordinate system is defined by:
<ul>
<li><u>its location</u>: given by the virtual grid intersection of <i>PlacementLocation</i></li>
<li><u>its x-axis direction</u>: given by the tangent of the line between the virtual grid intersection of the <i>PlacementLocation</i> and the virtual grid intersection of the <i>PlacementRefDirection</i>.</li>
</ul>

<table cellpadding=""2"" cellspacing=""2"" summary=""Geometry use definition"">
<tr><td align=""left"" valign=""top""><img src=""figures/IfcGridPlacement-Layout2.png"" alt=""with ref direction"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 245 &mdash; Grid placement with intersection</p></td></tr>
</table>

</EPM-HTML>"
4185;IfcObjectPlacement;"<EPM-HTML> 
<p><i>IfcObjectPlacement</i> is an abstract supertype for the special types defining the object coordinate system. The
<i>IfcObjectPlacement</i> has to be provided for each product that has a shape representation.</p>
<p>The object placement can be given:</p>
<ul>
<li>absolute: by an axis2 placement, relative to the world coordinate system,</li>
<li>relative: by an axis2 placement, relative to the object placement of another product,</li>
<li>by grid reference: by the virtual intersection and reference direction given by two axes of a design grid.</li>
</ul>
<p>In any case the object placement has to unambiguously define the object coordinate system as either two-dimensional axis placement (<i>IfcAxis2Placement2D</i>) or three-dimensional axis placement (<i>IfcAxis2Placement3D</i>). The axis placement may have to be calculated.</p>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
4190;IfcLocalPlacement;"<EPM-HTML> 

<p><i>IfcLocalPlacement</i> defines the relative placement of a product in relation to the
placement of another product or the absolute placement of a product within the geometric representation context of the project. </p>
<p><i>IfcLocalPlacement</i> allows that an <i>IfcProduct</i> can be placed by this <i>IfcLocalPlacement</i> (through
the attribute<i>ObjectPlacement</i>) within the local coordinate system of the object placement of another <i>IfcProduct</i>,
which is referenced by the <i>PlacementRelTo</i>. Rules to prevent cyclic relative placements have to be introduced on the
application level.</p>
<p>If the <i>PlacementRelTo</i> is not given, then
the <i>IfcProduct</i> is placed absolutely within the
world coordinate system.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.0.
</blockquote>

<p class=""head-use"">Geometry use definitions</p>
<p>The following conventions shall apply as default relative positions if the relative placement is used. The conventions are given for all five direct subtypes of <i>IfcProduct</i>, the <i>IfcSpatialStructureElement</i>, <i>IfcElement</i>, <i>IfcAnnotation</i>, <i>IfcGrid</i>, <i>IfcPort</i>. More detailed placement information is given at the level of subtypes of those five types mentioned.</p>
<ul>
  <li>For the subtypes of <i>IfcSpatialStructureElement</i> the following conventions apply
    <ul>
      <li><i>IfcSite</i> shall be placed absolutely within the world coordinate system established by the geometric
representation context of the <i>IfcProject</i> </li>
      <li><i>IfcBuilding</i> shall be placed relative to the local placement of <i>IfcSite</i> </li>
      <li><i>IfcBuildingStorey</i> shall be placed relative to the local placement of <i>IfcBuilding</i> </li>
    </ul>
  </li>
  <li>For <i>IfcGrid</i> and <i>IfcAnnotation</i> the convention applies that it shall be placed relative
    <ul>
      <li> to the local placement of its container (<i>IfcSite, IfcBuilding, IfcBuildingStorey</i>)
        <ul>
          <li>it should be the same container element that is referenced by the <i>IfcRelContainedInSpatialStructure</i>
containment relationship,</li>
        </ul>
      </li>
    </ul>
  </li>
  <li>For <i>IfcPort</i> the convention applies that it shall be placed relative
    <ul>
      <li> to the local placement of the element it belongs to (<i>IfcElement</i>)
        <ul>
          <li>it should be the same element that is referenced by the <i>IfcRelConnectsPortToElement</i> connection
relationship,</li>
        </ul>
      </li>
    </ul>
  </li>
  <li> For <i>IfcElement</i> the convention applies that it shall be placed relative:
    <ul>
      <li> to the local placement of its container (<i>IfcSite, IfcBuilding, IfcBuildingStorey</i>)
        <ul>
          <li>it should be the same container element that is referenced by the <i>IfcRelContainedInSpatialStructure</i>
containment relationship,</li>
        </ul>
      </li>
      <li>to the local placement of the <i>IfcElement</i> to which it is tied by an element composition relationship
        <ul>
          <li>for features that are located relative to the main component (such as openings), as expressed by <i>IfcRelVoidsElement</i> and<i> IfcRelProjectsElement</i>,</li>
          <li>for elements that fill an opening (such as doors or windows), as expressed by<i>IfcRelFillsElement</i>,</li>
          <li>for coverings that cover the element, as expressed by<i>IfcRelCoversBldgElements,</i></li>
          <li>for sub components that are aggregated to the main component, as expressed by <i> IIfcRelAggregates</i> and <i>IfcRelNests</i>)</li>
        </ul>
      </li>
    </ul>
  </li>
</ul>
<p>If the <i>PlacementRelTo</i> relationship is not given, then it defaults to an absolute placement within the world
coordinate system established by the referenced geometric representation context within the project. </p>

</EPM-HTML>"
4199;IfcMaterial;"<EPM-HTML>

<p><i>IfcMaterial</i> is a homogeneous or inhomogeneous
substance that can be used to form elements (physical products or
their components).</p>
<p><i>IfcMaterial</i> is the basic entity for material
designation and definition; this includes identification by name
and classification (via reference to an external classification),
as well as association of material properties (isotropic or
anisotropic) defined by (subtypes of)
<i>IfcMaterialProperties</i>. An instance of <i>IfcMaterial</i>
may be associated to an element or element type using the
<i>IfcRelAssociatesMaterial</i> relationship. The assignment
might either be direct as a single material information, or
via</p>
<ul>
<li>a material layer set</li>
<li>a material profile set</li>
<li>a material constituent set</li>
</ul>
<p>An <i>IfcMaterial</i> may also have presentation information
associated. Such presentation information is provided by
<i>IfcMaterialDefinitionRepresentation</i>, associating line
styles, hatching definitions or surface coloring/rendering
information to a material.</p>

<blockquote class=""history"">
HISTORY˙New entity in IFC2x4
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE˙ The attributes <i>Description</i> and <i>Category</i> have been added.
</blockquote>

</EPM-HTML>"
4206;IfcMaterialDefinition;"<EPM-HTML>
<p><i>IfcMaterialDefinition</i> is a general supertype for all
material related information items in IFC that have common
material related properties that may include association of
material with some shape parameters or assignments to identified
parts of a component.</p>
<p>There are three ways of assigning materials to a single component or
multiple components; they are characterized as:</p>
<ul>
<li>by layer - assigning a material to a layer with constant
thickness</li>
<li>by profile - assigning a material to a profile with a
constant of varying shape along an extrusion</li>
<li>by constituents - assigning a material to an identified part
of a component shape; the identification is by a keyword rather than 
by a shape parameter</li>
</ul>
<p>Each instantiable subtype of <i>IfcMaterialDefinition</i> may
have material properties assigned, or have an external
classification of its definition. It can be assigned to either a
subtype of <i>IfcElement</i>, or a subtype of
<i>IfcElementType</i> by using the objectified relationship
<i>IfcRelAssociatesMaterial</i>.</p>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x4
</blockquote>

</EPM-HTML>"
4217;IfcMaterialLayer;"<EPM-HTML>

<p><i>IfcMaterialLayer</i> is a single and identifiable part of an element which is constructed of a number of layers (one or more). Each <em>IfcMaterialLayer</em> has a constant thickness and is located relative to the referencing <em>IfcMaterialLayerSet</em> along the MlsBase.</p>

<blockquote>
<p><small>EXAMPLE&nbsp; A cavity wall with brick masonry used with
an air gap in between would be modeled using three
<em>IfcMaterialLayer</em>'s: [1] Brick, [2] Air gap, [3] Brick. The
inner layer ""Brick"" would have a <em>Name</em> = ""Brick"", an
individual <em>LayerThickness</em>, and potentially a
<em>Category</em> indicating it as ""load bearing"", and a
<em>Priority</em> that controls how this material layer interacts
with other material layers in wall connections.</small></p>
</blockquote>

<p>The <em>IfcMaterialLayer</em> may have a material layer name,
that might be different to the <em>IfcMaterial</em> name
referenced.</p>

<blockquote>
<p><small>EXAMPLE&nbsp; The <em>IfcMaterialLayer</em> name of an
insulation layer can be ""Insulation"", whereas the
<em>IfcMaterial</em> name is ""polystyrene insulating
boards"".</small></p>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC 1.5
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The attributes <em>Name</em>, <em>Description</em>, <em>Category</em>, <em>Priority</em> have been added at the end of attribute list. Data type of <em>LayerThickness</em> relaxed to <em>IfcNonNegativeLengthMeasure</em>.
</blockquote>

</EPM-HTML>"
4227;IfcMaterialLayerWithOffsets;"<EPM-HTML>
<p><i>IfcMaterialLayerWithOffsets</i> is a specialization of <i>IfcMaterialLayer</i> enabling definition
of offset values along edges (within the material layer set usage in parent layer set).</p>

<p>It defines the assignment of two offset values for a material
layer in its intended use within a material layer set. Offsets are
applied to the edges of layered elements (that is, in directions
perpendicular to the layer set direction). Offsets shall not be
used in layer set direction, that is, for modelling gaps (or overlaps)
between layers; gaps shall be modeled as layers with appropriate
material assignment for the void.</p>

<blockquote><small>EXAMPLE &nbsp; At the top of a standard wall,
with shape representation SweptSolid, offset of a given layer can
be specified in the direction of the extrusion (positive Z axis),
applied at the start or end (extruded from bottom to top), and with
a positive (extending above extrusion) or negative (ending below
extrusion).</small><br>
<br>
<small>Take a standard wall with the outer material layer for the
external isolation extending above extrusion by 100mm, but starting
at the same base height. In this case the following values are
set:</small>
<ul>
<li><small><i>OffsetDirection</i> = .AXIS3.</small></li>
<li><small><i>OffsetValues[1]</i> = 0.0</small></li>
<li><small><i>OffsetValues[2]</i> = 100.0 (default unit assumed to
be mm)</small></li>
</ul>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New Entity in IFC2x4.
</blockquote>

<p><span style=""text-decoration:underline"">Informal propositions</span></p>
<ol>
<li>The <em>OffestDirection</em> shall not be identical to the
<em>LayerSetDirection</em> of the corresponding
<em>IfcMaterialLayerSetUsage</em></li>
<li>The attribute ReferenceExtent shall be asserted at the
corresponding <em>IfcMaterialLayerSetUsage</em></li>
</ol>

<p class=""use-head"">Attribute use definition</p>
<p>The <em>OffsetValues</em> and <em>OffsetDirection</em> correspond to the definitions <em>ReferenceExtent</em> and <em>LayerSetDirection</em> at the <em>IfcMaterialLayerSetUsage</em>.</p>
<p>Figure 289 shows an example of applying the <em>OffsetValues</em> to the material layers of a standard wall.</p>

<table>
<tr><td><img src=""figures/IfcMaterialLayerWithOffsets_fig-1.png"" width=""600"" height=""600"" alt=""IfcMaterialLayerWithOffsets_fig-1""></td></tr>
<tr><td><p class=""figure"">Figure 289 &mdash; Material layer with offsets</p></td></tr>
</table>

</EPM-HTML>"
4234;IfcMaterialLayerSet;"<EPM-HTML>

<p><i>IfcMaterialLayerSet</i> is a designation by which materials of an element constructed of a number of material layers is known and through which the relative positioning of individual layers can be expressed.</p>

<p>The Material Layer Set Base (MlsBase) describes the axis along
which the material layers are positioned. The MlsBase is positioned
along the reference axis or reference plane of the element
supporting the <em>IfcMaterialLayerSetUsage</em> concept with a
potential offset (see here). The positive Material Layer Set
Direction (MlsDirection) describes the direction by which the
individual material layers, with their material layer thicknesses
are stacked. <em>IfcMaterialLayer</em>'s are stacked with no gap,
gaps within a material layer set are expresses as layers by
themselves.</p>

<blockquote>
<p><small>EXAMPLE A cavity brick wall would be modeled as
<em>IfcMaterialLayerSet</em> consisting of three
<em>IfcMaterialLayer</em>'s: brick, air cavity and brick. The air
gap is identified, using the <em>IsVentilated</em> flag at
<em>IfcMaterialLayer</em>.</small></p>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC 1.0
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Subtyped from <em>IfcMaterialDefinition</em>, the attribute <em>Description</em>
has been added at the end of attribute list.
</blockquote>

<p class=""use-head"">Attribute use definition</p>
<p>As shown in Figure 285, each <em>IfcMaterialLayerSet</em> implicitly defines a material
layer set base line (MlsBase), to which the start of the first
<em>IfcMaterialLayer</em> is aligned. The total thickness of a
layer set is calculated from the individual layer thicknesses, the
first layer starting from the MlsBase and following layers being
placed on top of the previous (no gaps or overlaps).</p>

<table>
<tr><td><img src=""figures/IfcMaterialLayerSet-01.png"" alt=""material layer set"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 285 &mdash; Material layer set</p></td></tr>
</table>

</EPM-HTML>"
4239;IfcMaterialProfileSet;"<EPM-HTML>

<p><i>IfcMaterialProfileSet</i> is a designation by which individual material(s) of a prismatic element (for example, beam or column) constructed of a single or multiple material profiles is known. If only a single material profile is used (the most typical case) then no <i>CompositeProfile</i> is asserted.</p>

<blockquote><small>NOTE ˙ In case of multiple <i>MaterialProfiles</i>, the relative positioning of individual profiles in <i>IfcMaterialProfileSet</i> are defined using the concept of <i>IfcCompositeProfileDef</i> in <i>IfcProfileResource</i> schema; otherwise, only one <i>MaterialProfile</i> is given and defined by an individual <i>IfcProfileDef</i> (subtype).</small></blockquote>

<blockquote class=""history"">
HISTORY˙New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
4244;IfcMaterialProfile;"<EPM-HTML>

<p><i>IfcMaterialProfile</i> is a single and identifiable part of an element which is constructed of a number of profiles (one or more).</p>

<blockquote><small>NOTE ˙ In case of multiple <i>MaterialProfiles</i>, the relative positioning of individual profiles in <i>IfcMaterialProfileSet</i> are defined using the concept of <i>IfcCompositeProfileDef</i> in <i>IfcProfileResource</i> schema; otherwise, only one <i>MaterialProfile</i> is given and defined by an individual <i>IfcProfileDef</i> (subtype).</small></blockquote>

<blockquote class=""history"">
HISTORY˙New Entity in IFC2x4
</blockquote>

</EPM-HTML>
"
4253;IfcMaterialProfileWithOffsets;"<EPM-HTML>

<p><i>IfcMaterialProfileWithOffsets</i> is a specialization of <i>IfcMaterialProfile</i> enabling definition offset values for profile start or end in its use in parent material profile set usage.</p>

<p>Relative positions of <i>IfcMaterialProfileWithOffsets</i> in the longitudinal direction of an element can be defined giving offsets at the start and end. This shall not be used for relative positions of individual profiles in the plane of profile definition, which is given in composite profile definition itself. Also, care should be taken especially when used with <i>IfcMaterialProfileSetUsageTapering</i> for correct start and end offset assignement.</p>

<blockquote class=""history"">
HISTORY˙ New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
4255;IfcMaterialConstituentSet;"<EPM-HTML>

<p><i>IfcMaterialConstituentSet</i> is a collection of individual material constituents, each assigning a material to a part of an element. The parts are only identified by a keyword (as opposed to an <i>IfcMaterialLayerSet</i> or <i>IfcMaterialProfileSet</i> where each part has an individual shape parameter (layer thickness or layer profile).</p>

<blockquote><small>EXAMPLE The different materials of a window
construction shall be provided for the window lining and the
window glazing. An <i>IfcMaterialConstituentSet</i> is assigned
to the window with two <i>IfcMaterialConstituent</i>'s, one with
the <i>Name</i> = 'Lining', one with the <i>Name</i> =
'Glazing'.</small><br>
<small>NOTE See the ""Material Use Definition"" at the individual
element to which an <i>IfcMaterialConstituentSet</i> may apply
for a required or recommended definition of such
keywords.</small></blockquote>

<blockquote class=""history"">
HISTORY˙New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
4259;IfcMaterialConstituent;"<EPM-HTML>

<p><i>IfcMaterialConstituent</i> is a single and identifiable part of an element which is constructed of a number of part (one or more) each having an individual material. The association of the material constituent to the part is provided by a keyword as value of the <small>Name</small> attribute.</p>

<blockquote><small>NOTE See the ""Material Use Definition"" at the individual element to which an <i>IfcMaterialConstituentSet</i> may apply for a required or recommended definition of such keywords as value for <i>IfcMaterialConstituent.Name</i>.</small></blockquote>

<blockquote class=""history"">
HISTORY˙New Entity in IFC2x4
</blockquote>

</EPM-HTML>"
4266;IfcMaterialRelationship;"<EPM-HTML>
<p><i>IfcMaterialRelationship</i>  defines a relationship between part and whole in material definitions (as in composite materials). The parts, expressed by the set of <i>RelatedMaterials</i>, are material constituents of which a single material aggregate is composed.</p>

<blockquote class=""history"">
HISTORY˙New Entity in IFC2x4
</blockquote>

</EPM-HTML>"
4270;IfcMaterialProperties;"<EPM-HTML>
<p><em>IfcMaterialProperties</em> is defined as an abstract
supertype for entities that apply material properties to material
definitions. A set of material properties that are assigned to an
individual material definiton may be identified by a <em>Name</em>
and a <em>Description</em>.</p>

<blockquote>
<p><small>NOTE&nbsp; The set of material properties can be assigned
to an individual <em>IfcMaterial</em>, a set or composite of
materials (<em>IfcMaterialConstituent</em>,
<em>IfcMaterialConstituentSet</em>), or set or individual material
layer (<em>IfcMaterialLayer</em>, <em>IfcMaterialLayerSet</em>), or
a set or individual material profile (<em>IfcMaterialProfile</em>,
<em>IfcMaterialProfileSet</em>)</small></p>
</blockquote>

<p>The applicable set of material properties is defined at the
subtype <em>IfcExtendedMaterialProperties</em>. It includes
material properties defined in this IFC specification and those
defined as user-defined extended material properties.</p>

<blockquote class=""history:>
HISTORY&nbsp; New Entity in IFC 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The subtypes that represented a fixed list of statically defined material properties, IfcMechanicalMaterialProperties, IfcThermalMaterialProperties, IfcHygroscopicMaterialProperties, IfcGeneralMaterialProperties, IfcOpticalMaterialProperties, IfcWaterProperties, IfcFuelProperties, IfcProductsOfCombustionProperties have been deleted, use the generic <em>IfcExtendedMaterialProperties</em> instead.
</blockquote>

</EPM-HTML>"
4275;IfcExtendedMaterialProperties;"<EPM-HTML>

<p>The <em>IfcExtendedMaterialProperties</em> assign a set of
defined material properties to associated material definitions.
This provides a mechanism to assign any material properties to
material. Those material properties that are defined as part of the
IFC specification are provided within the use definitions
below.</p>
<blockquote><small>NOTE The usage of this entity has changed in
IFC2x4, it is now used to express all material
properties.</small></blockquote>
<p>The <i>IfcProperty</i> (instantiable subtypes) is used to
express the individual material properties.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The attributes <em>Name</em> and <em>Description</em> are promoted to supertype,
attribute ExtendedProperties has been renamed to <em>Properties</em>.
</blockquote>

<p class=""use-head"">Extended property use definitions</p>
<p>The following sets of material property definitions are part of
this IFC release:</p>
<ul>
<li><a href=""text/Mprop_GeneralProperties.htm"" target=""SOURCE"">General Material Properties</a></li>
<li><a href=""text/Mprop_MechanicalProperties.htm"" target=""SOURCE"">General Mechanical Properties</a>
<ul>
<li><a href=""text/Mprop_MechanicalSteelProperties.htm"" target=""SOURCE"">Steel Mechanical Properties</a></li>
<li><a href=""text/Mprop_MechanicalConcreteProperties.htm"" target=""SOURCE"">Concrete Mechanical Properties</a></li>
<li><a href=""text/Mprop_MechanicalWoodProperties.htm"" target=""SOURCE"">Timber and Wood-based Mechanical Properties</a></li>
</ul>
</li>
<li><a href=""text/Mprop_ThermalProperties.htm"" target=""SOURCE"">General Thermal Properties</a></li>
<li><a href=""text/Mprop_HygroscopicProperties.htm"" target=""SOURCE"">General Hygroscopic Properties</a></li>
<li><a href=""text/Mprop_OpticalProperties.htm"" target=""SOURCE"">General Optical Properties</a></li>
<li><a href=""text/Mprop_WaterProperties.htm"" target=""SOURCE"">General Water Properties</a></li>
<li><a href=""text/Mprop_FuelProperties.htm"" target=""SOURCE"">General Fuel Properties</a></li>
<li><a href=""text/Mprop_ProductsOfCombustionProperties.htm"" target=""SOURCE"">General Products of Combustion Properties</a></li>
<li><a href=""text/Mprop_EnergyCalculationProperties.htm"" target=""SOURCE"">General Energy Calculation Properties</a></li>
</ul>
</EPM-HTML>"
4277;IfcMaterialClassificationRelationship;"<EPM-HTML>

<p><i>IfcMaterialClassificationRelationship</i> is a relationship assigning classifications to materials.</p>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE˙ The entity <i>IfcMaterialClassificationRelationship</i> is deprecated since IFC2x4 and shall no longer be used. Use <i>IfcExternalReferenceRelationship</i> instead.
</blockquote>

</EPM-HTML>
"
4280;IfcMaterialLayerSetUsage;"<EPM-HTML>
<p><i>IfcMaterialLayerSetUsage</i> determines the usage of
<i>IfcMaterialLayerSet</i> in terms of its location and
orientation relative to the associated element geometry. The
location of material layer set shall be compatible with the
building element geometry (that is, material layers shall fit inside
the element geometry). The rules to ensure the compatibility
depend on the type of the building element.</p>

<blockquote><small>EXAMPLE ˙For a cavity brick wall with shape
representation SweptSolid, the
<i>IfcMaterialLayerSet.TotalThickness</i> shall be equal to the
wall thickness. Also the <i>OffsetFromReferenceLine</i> shall
match the exact positions between the two shape representations
of <i>IfcWallStandardCase</i>, i.e. the
<i>IfcShapeRepresentation</i>'s with
<i>RepresentationIdentifier</i>=""Axis"" and
<i>RepresentationIdentifier</i>=""Body"".</small><br>
<br>
<small>NOTE ˙Refer to the implementation guide and agreements for
more information on matching between building element geometry
and material layer set usage.</small></blockquote>

<p>The <i>IfcMaterialLayerSetUsage</i> is always assigned to an
individual occurrence object only (i.e. to relevant subtypes of
<i>IfcElement</i>). The <i>IfcMaterialLayerSet</i>, referenced by
<i>ForLayerSet</i> can however be shared among several occurrence
objects. If the element type is available (i.e. the relevant
subtype of <i>IfcElementType</i>, then the
<i>IfcMaterialLayerSet</i> can be assigned to the type object.
The assignment between a˙subtype of <i>IfcElement</i> and the
<i>IfcMaterialLayerSetUsage</i> is handled by
<i>IfcRelAssociatesMaterial</i>.</p>

<p class=""use-head"">Use definition</p>
<p>The <i>IfcMaterialLayerSetUsage</i> is primarily intended to
be associated with planar building elements having a constant
thickness. With further agreements on the interpretation of
<i>LayerSetDirection</i>, the usage can be extended also to other
cases, e.g. to curved building elements, provided that the
material layer thicknesses are constant.</p>
<p>Generally, an element may be layered in any of its primary
directions, denoted by its x, y or z axis. The geometry use
definitions at each˙specific types of building element will
determine the applicable˙<i>LayerSetDirection</i>.</p>

<p>The following examples illustrate how the <i>IfcMaterialLayerSetUsage</i> attributes (LayerSetDirection, DirectionSense, OffsetFromReferenceLine) can
be used in different cases. The normative material use definitions are documented at each element (how these shall be used).</p>

<p>Figure 286 shows an example of the use of <i>IfcMaterialLayerSetUsage</i> aligned to the axis of a wall.</p>

<blockquote><small>EXAMPLE&nbsp; For a standard wall with extruded
geometric representation (vertical extrusion), the layer set
direction will be perpendicular to extrusion direction,
and˙</small><small>can be derived from the direction of the wall
axis. With the <i>DirectionSense</i></small><small>(positive in
this example) the individual <i>IfcMaterialLayers</i> are
assigned consecutively right-to-left or left-to-right. For a
curved wall, ""direction denoting the wall thickness"" can be
derived from the direction of the wall axis, and it will remain
perpendicular to the wall path.</small> <small>The
<i>DirectionSense</i></small><small><i>˙</i>applies as well.<br>
<br>
NOTE&nbsp; According to the <i>IfcWallStandardCase</i> material use
definition the <i>LayerSetDirection</i> for
<i>IfcWallStandardCase</i> is always AXIS2 (i.e. along the
y-axis), as shown in this example.</small></blockquote>

<table>
<tr><td><img src=""figures/IfcMaterialLayerSetUsage_Wall-01.png"" alt=""Mls usage""border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 286 &mdash; Material layer set usage for wall</p></td></tr>
</table>

<p>Figure 287 shows an example of the use of <i>IfcMaterialLayerSetUsage</i> aligned to a slab.</p>

<blockquote><small>EXAMPLE&nbsp;˙For a slab with perpendicular
extruded geometric representation, the <i>LayerSetDirection</i>
will coincide with the extrusion direction (in positive or
negative sense). In this example, the material layer set base is
the extruded profile and consistent with the
<i>IfcExtrudedAreaSolid.Position</i>,˙</small><small>with the
<i>DirectionSense</i></small><small>being positive, the
individual <i>IfcMaterialLayers</i> are built up from the base
towards positive z direction in this case.<br>
<br>
NOTE ˙</small><small>According to the <i>IfcSlabStandardCase</i>
material use definition the <i>LayerSetDirection</i> for
<i>IfcSlabStandardCase</i> is always AXIS3 (i.e. along the
z-axis).</small></blockquote>

<table>
<tr><td><img src=""figures/IfcMaterialLayerSetUsage_Slab-01.png"" alt=""Mls usage"" border=""0"" height=""320"" width=""601""></td></tr>
<tr><td><p class=""figure"">Figure 287 &mdash; Material layer set usage for slab</p></td></tr>
</table>

<p>Figure 288 shows an example of the use of <i>IfcMaterialLayerSetUsage</i> aligned to a roof slab with non-perpendicular extrusion.</p>

<blockquote><small>EXAMPLE&nbsp;˙For a slab with non-perpendicular
extruded geometric representation, the guidelines above apply as
well</small><small>. The material layer thickness and the
<i>OffsetFromReferenceLine</i> is always measured
perpendicularly, even if the extrusion direction is not
perpendicular. Therefore the total material layer thickness is
not equal to the extrusion depth of the
geometry.</small></blockquote>

<table>
<tr><td><img src=""figures/IfcMaterialLayerSetUsage_RoofSlab-01.png"" alt=""Mls usage"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 288 &mdash; Material layer set usage for roof slab</p></td></tr>
</table>

</EPM-HTML>"
4286;IfcMaterialUsageDefinition;"<EPM-HTML>
<p><i>IfcMaterialUsageDefinition</i> is a general supertype for all
material related information items in IFC that have occurrence
specific assignment parameters to assign a set of materials with
shape parameters to a reference geometry item of that
component.</p>
<p>There are two ways of assigning a set of materials with shape
parameters:</p>
<ul>
<li>a layer set to a reference curve - assigning a material layer
set with material layers having a sequence and thickness
parameter to a reference curve of an element - represented by the
'Axis' shape representation of that element</li>
<li>a profile set to a cardinal point - assigning a material
profile set with assigned profile geometry and insertion points
to a reference curve by an offset, called ""cardinal point"" - the
reference curve is represented by the 'Axis' shape representation
of that element</li>
</ul>
<p>Each instantiable subtype of <i>IfcMaterialUsageDefinition</i>
has to be assigned to a subtype of <i>IfcElement</i> by using the
objectified relationship <i>IfcRelAssociatesMaterial</i>; it is
only valid in conjunction with an element occurrence.</p>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x4
</blockquote>

<p><u>Informal proposition</u></p>
<ol>
<li>It is illegal to assign a subtype of
<i>IfcMaterialUsageDefinition</i> to a subtype of
<i>IfcElementType</i>, it shall only be assigned to an element
occurrence.</li>
</ol>
</EPM-HTML>"
4290;IfcMaterialProfileSetUsage;"<EPM-HTML>

<p><i>IfcMaterialProfileSetUsage</i> determines the usage of <i>IfcMaterialProfileSet</i> in terms of its location relative to the associated element geometry. The location of a material profile set shall be compatible with the building element geometry (that is, material profiles shall fit inside the element geometry). The rules to ensure the compatibility depend on the type of the building element. For building elements with shape representations which are based on extruded solids, this is accomplished by referring to the identical profile definition in the shape model as in the material profile set.</p>

<blockquote><small>NOTE ˙ Refer to the implementation guide and agreements for more information on matching between building element geometry and material profile set usage.</small></blockquote>
<blockquote><small>NOTE ˙ The referenced <i>IfcMaterialProfileSet</i> may represent a single material
profile, or a composite profile with two or more material profiles.</small></blockquote>

<blockquote class=""history"">
HISTORY˙New Entity in IFC2x4.
</blockquote>

</EPM-HTML>"
4295;IfcMaterialProfileSetUsageTapering;"<EPM-HTML>

<p><i>IfcMaterialProfileSetUsageTapering</i> specifies dual material profile sets in association with tapered prismatic (beam- or column-like) elements.</p>

<blockquote class=""history"">
HISTORY˙ New entity in IFC 2x4
</blockquote>

<p class=""head-use"">Usage with tapered building elements</p>
<p>The inherited attribute <i>ForProfileSet</i> specifies the
profile and material at the start of the member,
<i>ForProfileEndSet</i> at its end. Start and end correspond to
the extrusion direction in the shape model of the shape
representation of the element or element type.</p>
<p>Both material profile sets should refer to the same material,
that is, only differ with respect to their profiles.</p>

<p class=""head-use"">Usage with structural analysis curve members</p>
<p><i>IfcMaterialProfileSetUsageTapering</i> may be used with the
structural analysis idealization
(<i>IfcStructuralCurveMember</i>) of uniform members as well as
of tapered members.</p>
<p>In case of uniform members, <i>ForProfileSet</i> and
<i>ForProfileEndSet</i> refer to the same material profile set.
In case of tapered members, <i>ForProfileSet</i> specifies the
profile and material at the start of the member,
<i>ForProfileEndSet</i> at its end. Start and end correspond to
the edge direction in the topological representation of the curve
member.</p>

</EPM-HTML>"
4304;IfcMaterialList;"<EPM-HTML>
<p><i>IfcMaterialList</i> is a list of the different materials
that are used in an element.</p>

<blockquote><small>NOTE: The class <i>IfcMaterialList</i> will
normally be used where an element is described at a more abstract
level. For example, for an architectural specification writer,
the only information that may be needed about a concrete column
is that it contains concrete, reinforcing steel and mild steel
ligatures. It shall not be used for elements consisting of
material layers when the different layers can be defined and the
class <i>IfcMaterialLayerSet</i> can be used. Also,
<i>IfcMaterialList</i> shall not be used for elements consisting
of a single identifiable material (for example, to represent anisotropic
material).</small></blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE˙ The entity <i>IfcMaterialList</i> is deprecated and shall no longer
be used. Use <i>IfcMaterialConstituentSet</i> instead.
</blockquote>

</EPM-HTML>"
4367;IfcDerivedUnit;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: A derived unit is an expression of units.</p>

<blockquote class=""example"">
EXAMPLE: Newton per square millimetre is a derived unit.
</blockquote>

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 name: derived_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
4374;IfcDerivedUnitElement;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: A derived unit element is one of the unit quantities 
which makes up a derived unit.</p>

<blockquote class=""example"">
EXAMPLE: Newtons per square millimetre is a derived unit. 
It has two elements, Newton whose exponent has a value of 1 and millimetre whose exponent is -2.
</blockquote>

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 name: derived_unit_element, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1. 
</blockquote>

</EPM-HTML>"
4377;IfcNamedUnit;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: A named unit is a unit quantity associated with the word, or group of words, by which the unit is identified.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: named_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New type in IFC Release 1.5.1.
</blockquote>

<EPM-HTML>"
4384;IfcContextDependentUnit;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: A context dependent unit is a unit which is not related to the SI system.</p>

<blockquote class=""note"">
NOTE The number of parts in an assembly is a physical quantity measured in units that may be called ""parts"" but which cannot be related to an SI unit.
</blockquote>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: context_dependent_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
4388;IfcConversionBasedUnit;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: A conversion based unit is a unit that is defined based on a measure with unit.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: conversion_based_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC 2x3 change: standard names of typical units added.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC 2x4 change: further names added: square inch, square foot, square mile, square yard, cubic inch, cubic foot, cubic yard, fluid ounce UK/US, ton UK/US, degree.
</blockquote>

<p>Example: An inch is a converted unit. It is from the Imperial system, its name is ""inch"" and it can be related to the si unit, millimetre, through a measure with unit whose value is 25.4 millimetre. A foot is also a converted unit. It is from the Imperial system, its name is ""foot"" and it can be related to an <i>IfcSIUnit</i>, millimetre, either directly or through the unit called ""inch"". Note that several US customary units differ from Imperial units (nonmetric English units) of the same name.</p>

<p>To identify some commonly used conversion based units, the standard designations (case insensitive) for the Name attribute include the following:</p>

<table border=""1"">
	<tr><td><i><b>Name</b></i></td>	<td><i><b>Description</b></i></td></tr>
	<tr><td>'inch'</td>		<td>Length measure equal to 25.4 mm</td></tr>
	<tr><td>'foot'</td>		<td>Length measure equal to 304.8 mm</td></tr>
	<tr><td>'yard'</td>		<td>Length measure equal to 914 mm</td></tr>
	<tr><td>'mile'</td>		<td>Length measure equal to 1609 m</td></tr>
	<tr><td>'square inch'</td>	<td>Area measure equal to 0.0006452 square meters</td></tr>
	<tr><td>'square foot'</td>	<td>Area measure equal to 0.09290 square meters</td></tr>
	<tr><td>'square yard'</td>	<td>Area measure equal to 0.83612736 square meters</td></tr>
	<tr><td>'acre'</td>		<td>Area measure equal to 4046.86 square meters</td></tr>
	<tr><td>'square mile'</td>	<td>Area measure equal to 2 588 881 square meters</td></tr>
	<tr><td>'cubic inch'</td>	<td>Volume measure equal to 0.00001639 cubic meters</td></tr>
	<tr><td>'cubic foot'</td>	<td>Volume measure equal to 0.02832 cubic meters</td></tr>
	<tr><td>'cubic yard'</td>	<td>Volume measure equal to 0.7636 cubic meters</td></tr>
	<tr><td>'litre'</td>		<td>Volume measure equal to 0.001 cubic meters</td></tr>
	<tr><td>'fluid ounce UK'</td>	<td>Volume measure equal to 0.0000284130625 cubic meters</td></tr>
	<tr><td>'fluid ounce US'</td>	<td>Volume measure equal to 0.00002957353 cubic meters</td></tr>
	<tr><td>'pint UK'</td>		<td>Volume measure equal to 0.000568 cubic meters</td></tr>
	<tr><td>'pint US'</td>		<td>Volume measure equal to 0.000473 cubic meters</td></tr>
	<tr><td>'gallon UK'</td>	<td>Volume measure equal to 0.004546 cubic meters</td></tr>
	<tr><td>'gallon US'</td>	<td>Volume measure equal to 0.003785 cubic meters</td></tr>
	<tr><td>'degree'</td>		<td>Angle measure equal to &pi;/180 rad</td></tr>
	<tr><td>'ounce'</td>		<td>Mass measure equal to 28.35 g</td></tr>
	<tr><td>'pound'</td>		<td>Mass measure equal to 0.454 kg</td></tr>
	<tr><td>'ton UK'</td>		<td>Mass measure equal to 1016.0469088 kg, also known as long ton, gross ton, shipper's ton</td></tr>
	<tr><td>'ton US'</td>		<td>Mass measure equal to 907.18474 kg, also known as short ton, net ton</td></tr>
	<tr><td>'lbf'</td>		<td>Force measure equal to 4.4482216153 N, pound-force</td></tr>
	<tr><td>'kip'</td>		<td>Force measure equal to 4448.2216153 N, kilopound-force</td></tr>
	<tr><td>'psi'</td>		<td>Pressure measure equal to 6894.7572932 Pa, pound-force per square inch</td></tr>
	<tr><td>'ksi'</td>		<td>Pressure measure equal to 6894757.2932 Pa, kilopound-force per square inch</td></tr>
	<tr><td>'minute'</td>		<td>Time measure equal to 60 s</td></tr>
	<tr><td>'hour'</td>		<td>Time measure equal to 3600 s</td></tr>
	<tr><td>'day'</td>		<td>Time measure equal to 86400 s</td></tr>
	<tr><td>'btu'</td>		<td>Energy measure equal to 1055.056 J, British Thermal Unit</td></tr>
</table>

</EPM-HTML>"
4393;IfcConversionBasedUnitWithOffset;"<EPM-HTML>

<p><i>IfcConversionBasedUnitWithOffset</i> is a unit which is converted from another unit by applying a conversion factor and an offset.</p>

<blockquote class=""history"">
HISTORY New entity in IFC 2x4.
</blockquote>

<p>Example: The temperature unit Fahrenheit is based on the temperature unit Kelvin as follows:</p>

<blockquote><i>f</i>&nbsp;=&nbsp;<i>k</i>&nbsp;&middot;&nbsp;1.8&nbsp;&ndash;&nbsp;459.67</blockquote>

<p>wherein <i>k</i> is an absolute temperature expressed in Kelvin and <i>f</i> is the same temperature in Fahrenheit.  The following entity instances provide Fahrenheit as a unit:</p>

<blockquote><code>
IfcConversionBasedUnitWithOffset(<br>
&nbsp;&nbsp;&nbsp;&nbsp;IfcDimensionalExponents(0, 0, 0, 0, 1, 0, 0),<br>
&nbsp;&nbsp;&nbsp;&nbsp;THERMODYNAMICTEMPERATUREUNIT,<br>
&nbsp;&nbsp;&nbsp;&nbsp;'Fahrenheit',<br>
&nbsp;&nbsp;&nbsp;&nbsp;IfcMeasureWithUnit(<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;IfcThermodynamicTemperatureMeasure(1.8),<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;IfcSiUnit(THERMODYNAMICTEMPERATUREUNIT, ?, KELVIN)),<br>
&nbsp;&nbsp;&nbsp;&nbsp;-459.67);
</code></blockquote>

</EPM-HTML>
"
4395;IfcMeasureWithUnit;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: A measure with unit is the specification of a physical quantity  as defined in ISO 31 (clause 2).</p>

<p><i>IfcMeasureWithUnit</i> has two usages:<br>
1. For representing measure value together with its unit on the entity type attribute level; thus
   overriding the IFC model global unit assignments.<br>
2. For conversion based unit to give the conversion rate and its base.
</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: measure_with_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
4567;IfcSIUnit;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-41:1992</u>: An SI unit is the fixed quantity used as a standard in terms of which items are measured as defined by ISO 1000 (clause 2).</p>

<p><i>IfcSIUnit</i> covers both standard base SI units such as meter and second, and derived SI units such as Pascal, square meter and cubic meter.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: si_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
4619;IfcDimensionalExponents;"<EPM-HTML>

<P><U>Definition from ISO/CD 10303-41:1992</U>: The dimensionality of any quantity can be expressed as a product of powers of the dimensions of base quantities. 
The dimensional exponents entity defines the powers of the dimensions of the base quantities. All the physical 
quantities are founded on seven base quantities (ISO 31 (clause 2)).
</P>
<BLOCKQUOTE><FONT SIZE=""-1"">NOTE: Length, mass, time, electric current, thermodynamic temperature, amount of substance, 
and luminous intensity are the seven base quantities.
</FONT></BLOCKQUOTE>

<BLOCKQUOTE><FONT SIZE=""-1"">EXAMPLE: A length of 2 millimetres has a length exponent of 1. The remaining exponents 
are equal to 0.
</FONT></BLOCKQUOTE>

<BLOCKQUOTE><FONT SIZE=""-1"">EXAMPLE: A velocity of 2 millimetres per second has a length exponent of 1 and 
a time exponent of -1. The remaining exponents are equal to 0.
</FONT></BLOCKQUOTE>

<BLOCKQUOTE><FONT SIZE=""-1"">
  NOTE Corresponding STEP name: dimensional_exponents, please refer to ISO/IS 10303-41
  for the final definition of the formal standard.
</FONT></BLOCKQUOTE>

<BLOCKQUOTE><FONT SIZE=""-1"" COLOR=""#0000FF"">
  HISTORY New entity in IFC Release 1.5.1. 
</FONT></BLOCKQUOTE>

</EPM-HTML>"
4709;IfcMonetaryUnit;"<EPM-HTML>

<p><i>IfcMonetaryUnit</i> is a unit to define currency for money.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE: Type of the attribute Currency changed.
</blockquote>

</EPM-HTML>
"
4711;IfcUnitAssignment;"<EPM-HTML>

<p><i>IfcUnitAssignment</i> indicates a set of units which may be assigned. Within an <i>IfcUnitAssigment</i> each unit definition shall be unique; that is, there shall be no redundant unit definitions for the same unit type such as length unit or area unit. For currencies, there shall be only a single <i>IfcMonetaryUnit</i> within an <i>IfcUnitAssignment</i>.</p>

<blockquote><small>
NOTE&nbsp; A project (<i>IfcProject</i>) has a unit assignment which establishes a set of units which will be used globally within the project, if not otherwise defined. Other objects may have local unit assignments if there is a requirement for them to make use of units which do not fall within the project unit assignment.</small>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
4719;IfcFillAreaStyleHatching;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The fill area style hatching defines a styled pattern of curves for hatching an annotation fill area or a surface.</p>

<p>The <i>IfcFillAreaStyleHatching</i> is used to define simple, vector-based hatching patterns, based on styled straight lines. The curve font, color and thickness is given by the <i>HatchLineAppearance</i>, the angle by the <i>HatchLineAngle</i> and the distance to the next hatch line by <i>StartOfNextHatchLine</i>, being either an offset distance or a vector.</p>

<blockquote class=""note"">
NOTE&nbsp; If the hatch pattern involves two (potentially crossing) rows of hatch lines, then two instances of <i>IfcFillAreaStyleHatching</i> should be assigned to the <i>IfcFillAreaStyle</i>. Both share the same (virtual) point of origin of the hatching that is used by the reference hatch line (or the <i>PointOfReferenceHatchLine</i> if there is an offset).
</blockquote>

<p>For better control of the hatching appearance, when using hatch lines with other fonts then continuous, the <i>PatternStart</i> allows to offset the start of the curve font pattern along the reference hatch line (if not given, the <i>PatternStart</i> is at zero distance from the virtual point of origin). If the reference hatch line does not go through the origin (of the virtual hatching coordinate system), it can be offset by using the&nbsp;<i>PatternStart&nbsp;</i><strike><i>PointOfReferenceHatchLine</i>.</strike></p>

<blockquote class=""note"">
NOTE&nbsp; The coordinates of the <i>PatternStart </i><strike>and the </strike><i><strike>PointOfReferenceHatchLine</strike></i> are given relative to the assumed 0., 0. virtual point of origin at which the hatch pattern is later positioned by the <i>FillStyleTarget</i> point at <i>IfcAnnotationFillAreaOccurrence</i>. The measure values are given in global drawing length units and apply to the target plot scale for the scale depended representation subcontext.
</blockquote>

<blockquote class=""deprecated"">
NOTE &nbsp;The use of </small><small><i>PointOfReferenceHatchLine</i> is deprecated.
</blockquote>

<p>Figure 292 illustrates hatch attributes.</p>

<table>
<tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2""
 width=""100%""> <tbody> <tr> <td align=""left""
 valign=""top"" width=""300""><img alt=""hatch example 1""
 src=""figures/IfcFillAreaStyleHatching_Fig1.gif"" height=""300""
 width=""300""></td> <td align=""left""
 valign=""top""><small><u>Example 1</u><br>
This example shows simple hatching given by using a curve font ""continuous"" at <i>HatchLineAppearance</i>.<br>
<br>
The distance of hatch lines is given by a positive length measure. The
angle (here 45' if measures in degree) is provided by <i>HatchLineAngle</i>.<br>
<br>
The <i>PatternStart</i> is
set to NIL ($) in this example.</small></td> <td
 align=""left"" valign=""top"" width=""300""><img
 alt=""hatch example 2""
 src=""figures/IfcFillAreaStyleHatching_Fig2.gif"" height=""300""
 width=""300""></td> <td align=""left""
 valign=""top""><small><u>Example 2</u><br>
This shows hatching from example 1 with using a different curve font at <i>HatchLineAppearance</i>.<br>
<br> </small><small>The distance of hatch lines is given by a positive
length measure, therefore the font pattern start is at a point at the
next hatch line given by a vector being perpendicular to the point of
origin at the reference hatch line.<br> <br> </small><small>The
<i>PatternStart</i> is set to NIL ($) in this example.</small></td>
</tr> <tr> <td width=""300""><img
 alt=""hatch example 3""
 src=""figures/IfcFillAreaStyleHatching_Fig3.gif"" height=""300""
 width=""300""></td> <td align=""left""
 valign=""top""><small><u>Example 3</u><br>
This example uses hatching from example 2 with a vector to determine the pattern start of the next hatch lines.<br> <br>
The pattern start is the beginning of the first visual curve font pattern segment at <i>IfcCurveFont.CurveFont</i>.<br> <br> </small><small>The <i>PatternStart</i> is set to NIL ($) in this example.</small><br>
</td> <td width=""300""><img alt=""hatch example 4""
 src=""figures/IfcFillAreaStyleHatching_Fig4.gif"" height=""300""
 width=""300""></td> <td align=""left""
 valign=""top""><small><u>Example 4</u><br>
This example uses hatching from example 3 where the pattern start is offset from the point of origin at the reference hatch line. That is, the first visible curve font pattern segment now does not start at the point of origin at the reference hatch line.</small><br>
<small><br> </small></td> </tr> <tr>
<td><img alt=""hatch example 5""
 src=""figures/IfcFillAreaStyleHatching_Fig5.gif"" height=""300""
 width=""300""></td> <td align=""left""
 valign=""top""><small><u>Example 5</u><br>
This example uses hatching from example 4 where the hatch pattern is shifted against the underlying coordinate system.<br> <br>
The point that is mapped to the insertion point of the <i>IfcAnnotationFillAreaOccurrence</i> now has an X and Y offset from the start of the reference hatch line. That is, the reference hatch line now does not go through the insertion point of the hatching.<br> <br> <br> <br> </small></td>
<td valign=""top""><img alt=""fig 6""
 src=""figures/IfcFillAreaStyleHatching_Fig6.gif"" height=""300""
 width=""300""></td> <td valign=""top""><small><u>Example 6</u><br>
This example shows use of <i>IfcFillAreaStyleHatching</i> attributes for two <i>IfcFillAreaStyleHatching</i>'s within one <i>IfcFillAreaStyle</i>.<br> <br>Note that the <i>PatternStart</i> now displaces both the reference hatch line from the point of origin and the start of the curve pattern. This can be used in cases when more than one <i>IfcFillAreaStyleHatching</i> is used in an <i>IfcFillAreaStyle</i> in order to place rows of hatch lines with an offset from each other.</small></td>
</tr> </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 292 &mdash; Fill area style hatching</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: fill_area_style_hatching. Please refer to ISO/IS 10303-46:1994, p. 108 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The <i>IfcFillAreaStyleHatching</i> has been changed by making the attributes PatternStart and PointOfReferenceHatchLine OPTIONAL. The attribute <i>StartOfNextHatchLine</i> has changed to a SELECT with the additional choice of <i>IfcPositiveLengthMeasure</i>. Upward compatibility for file based exchange is guaranteed.
</blockquote>

</EPM-HTML>"
4728;IfcCurveStyle;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A curve style specifies the visual appearance of curves.</p>

<p>An <i>IfcCurveStyle</i> provides the style table for presentation information assigned to geometric curves. The style is defined by a color, a font and a width. The <i>IfcCurveStyle</i> defines curve patterns as model patterns, that is, the distance between visible and invisible segments of curve patterns are given in model space dimensions (that have to be scaled using the target plot scale).</p>

<p>Styles are intended to be shared by multiple <i>IfcStyledItem</i>'s, assigning the style to occurrences of (subtypes of) <i>IfcGeometricRepresentationItem</i>'s. Measures given to a font pattern or a curve width are given in global drawing length units.</p>

<blockquote class=""note"">
NOTE&nbsp; global units are defined at the single <i>IfcProject</i> instance, given by <i>UnitsInContext:IfcUnitAssignment</i>, the same units are used for the geometric representation items and for the style definitions.
</blockquote>

<p>The measure values for font pattern and curve width apply to the model space with a target plot scale provided for the correct appearance in the default plot scale.. For different scale and projection dependent curve styles a different instance of <i>IfcCurveStyle</i> needs to be used by <i>IfcPresentationStyleAssignment</i> for different <i>IfcGeometricRepresentationSubContext</i> dependent representations.</p>

<blockquote>
NOTE&nbsp; the target plot scale is given by <i>IfcGeometricRepresentationSubContext.TargetScale</i>.
</blockquote>

<p>An <i>IfcCurveStyle</i> can be assigned to <i>IfcGeometricRepresentationItem</i>'s via the <i>IfcPresentationStyleAssignment</i> through an intermediate <i>IfcStyledItem</i> or <i>IfcAnnotationCurveOccurrence</i>.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: curve_style. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.</small> </font>
</blockquote>

</EPM-HTML>"
4733;IfcPresentationStyle;"<EPM-HTML>

<p><i>IfcPresentationStyle</i> is an abstract generalization of style table for presentation information assigned to geometric representation items. It includes styles for curves, areas, surfaces, text and symbols. Style information may include colour, hatching, rendering, and text fonts.</p>

<p>Each subtype of&nbsp; <i>IfcPresentationStyle</i> can be assigned to <i>IfcGeometricRepresentationItem</i>'s via the <i>IfcPresentationStyleAssignment</i> through an intermediate <i>IfcStyledItem</i> or one of its subtypes.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

</EPM-HTML>"
4740;IfcTextStyle;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The text style is a presentation style for annotation text.</p>

<p>The <i>IfcTextStyle</i> provides the text style table for presentation information assigned to text literals. The style is defined by color, text font characteristics, and text box characteristics. The definitions are based upon:</p>
<ul>
  <li>definitions from ISO/IS 10303-46:1994 for (old) vector based and monospace text.</li>
  <li>definitions from <a target=""_blank"" href=""http://www.w3.org/TR/REC-CSS1"">Cascading Style Sheets, level 1</a>, W3C Recommendation 17 Dec 1996, revised 11 Jan 1999, CSS1, for all true type text. The use of the CSS1 definitions is the preferred way to represent text styles.</li>
</ul>

<p>An <i>IfcTextStyle</i>, when representing (old) vector based and monospace text, is instantiated with:</p>
<ul>
  <li><i>TextCharacterAppearance</i>:: <i>IfcTextStyleForDefinedFont</i> (with <i>BackgroundColour</i> = NIL)</li>
  <li><i>TextStyle</i>:: <i>IfcTextStyleWithBoxCharacteristics</i></li>
  <li><i>TextFontStyle</i>:: <i>IfcDraughtingPreDefinedTextFont</i> or <i>IfcExternallyDefinedTextFont</i></li>
</ul>

<p>An <i>IfcTextStyle</i>, when representing (new) true type text, based on CSS1 definitions, is instantiated with:</p>
<ul>
  <li><i>TextCharacterAppearance</i>:: <i>IfcTextStyleForDefinedFont</i></li>
  <li><i>TextStyle</i>:: <i>IfcTextStyleTextModel</i></li>
  <li><i>TextFontStyle</i>:: <i>IfcTextStyleFontModel</i></li>
</ul>

<p>An <i>IfcTextStyle</i> can be assigned to <i>IfcTextLiteral</i> via the <i>IfcPresentationStyleAssignment</i> through an intermediate <i>IfcAnnotationTextOccurrence</i>.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: text_style. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard. In order to avoid ANDOR subtype relationships, the <i>IfcTextBlockStyleSelect</i> has been introduced that allows the combination of a text style as having box characteristic, and/or having spacing, or having none of those additional properties.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding CSS1 definitions are: Font properties (font-family, font-style, font-variant, font-weight, font-size), Color and background properties (color, background-color) and Text properties (word-spacing, letter-spacing, text-decoration, text-transform, text-align, text-indent, line-height).
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The <i>IfcTextStyle</i> has been changed by adding <i>TextFontStyle</i> and different data types for <i>TextStyle</i> and <i>IfcCharacterStyleSelect</i>.
</blockquote>

</EPM-HTML>"
4746;IfcTextStyleForDefinedFont;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A text style for defined font is a character glyph style for pre-defined or externally defined text fonts.</p>

<p><u>Definition from CSS1 (W3C Recommendation)</u>: These properties describe the color (often called foreground color) and background of an element (i.e. the surface onto which the content is rendered). One can set a background color.</p>

<blockquote>
NOTE&nbsp; The CSS1 definition allows also for a background image. This has not been incorporated into IFC.
</blockquote>

<p>The <i>IfcTextStyleForDefinedFont</i> combines the text font color with an optional background color, that fills the text box, defined by the planar extent given to the text literal.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: text_style_for_defined_font. Please refer to ISO/IS
10303-46:1994, p.122 for the final definition of the formal standard. The attribute <i>BackgroundColour</i>
has been added.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding CSS1 definitions are Color and background properties (color, background-color).</font>
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The <i>IfcTextStyleForDefinedFont</i> has been added and replaces <i>IfcColour</i> at the <i>IfcCharacterStyleSelect</i>.
</blockquote>

</EPM-HTML>"
4749;IfcPreDefinedCurveFont;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The predefined curve font type is an abstract supertype provided to define an application specific curve font. The name label shall be constrained in the application protocol to values that are given specific meaning for curve fonts in that application protocol.</p>

<blockquote class=""note"">
NOTE: The <I>IfcPreDefinedCurveFont</I> is an abstract entity, subtypes of it provide the predefined curve font by agreement of the values of the inherited <I>Name</I> attribute. Currently the only subtype provided is <I>IfcDraughtingPreDefinedCurveFont</I>.
</blockquote> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 name: pre_defined_curve_font. Please refer to ISO/IS 10303-46:1994, p. 103 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4751;IfcDraughtingPreDefinedCurveFont;"<EPM-HTML>

<p>The draughting predefined curve font type defines a selection of widely used curve fonts for draughting purposes by name.</p> 

<blockquote class=""note""> 
NOTE&nbsp; The <I>IfcDraughtingPreDefinedCurveFont</I> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&#151;Product data representation and exchange, Part 46 Technical Corrigendum 2: Integrated generic resources: Visual presentation.
</blockquote> 

<p>Figure 291 (from ISO 10303-46 TC2) illustrates predefined curve fonts.</p>
<table>
<tr><td><img src=""figures/IfcDraughtingPreDefinedCurveFont_Fig1.gif"" alt=""predefined fonts"" width=""550"" height=""330"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 291 &mdash; Draughting predefined curve font</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; If the <I>IfcDraughtingPreDefinedCurveFont</I> is used within an <I>IfcCurveStyleFontAndScaling</I> then the segment and space lengths that are given in the table are as such for the scale factor 1.0
</blockquote> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 name: pre_defined_curve_font. Please refer to ISO/IS 10303-46:1994 TC2, page 12 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4756;IfcTextStyleWithBoxCharacteristics;"<EPM-HTML>

<p>The text style with box characteristics allows the presentation of annotated text by specifying the characteristics of the character boxes of the text and the spacing between the character boxes.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcTextStyleWithBoxCharacteristics</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&mdash;Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation.
</blockquote>

<p>The <i>IfcTextStyleWithBoxCharacteristics</i> is mainly used to provide some compatibility with ISO10303. Its usage is restricted to monospace text fonts (having uniform character boxes) and simple vector based text fonts. For true text fonts however the use of <i>IfcTextStyleTextModel</i> is required.</p>

<p>Figure 296 (from ISO 10303-46, page 91) illustrates angles.  Figure 297 illustrates attribute use.</p>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" width=""100%"">
  <tbody>
    <tr>
      <td><img src=""figures/IfcTextStyleWithBoxCharacteristics_Fig1.gif"" alt=""box angles"" border=""0"" height=""270"" width=""400""></td>
      <td><img alt=""use of attributes"" src=""figures/IfcTextStyleWithBoxCharacteristics_Fig2.gif"" height=""264"" width=""556""></td>
    </tr>
    <tr>
      <td><p class=""figure"">Figure 296 &mdash; Text style box angles</p></td>
      <td><p class=""figure"">Figure 297 &mdash; Text style box attributes</p></td>
    </tr>
  </tbody>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: text_style_with_box_characteristics. Please refer to ISO/IS 10303-46:1994, p. 123 for the final definition of the formal standard. The four optional attributes <i>BoxHeight, BoxWidth, BoxSlantAngle, BoxRotateAngle</i> are included directly at the entity, and are not handled through the box_characteristic_select selecting box_height, box_width, box_slant_angle, box_rotate_angle, each being defined types.&nbsp;
The <i>CharacterSpacing</i> attribute has been added from ISO/IS 10303-46:1994 entity text_style_with_spacing.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The attribute item <i>CharacterSpacing</i> has been added.
</blockquote>

</EPM-HTML>"
4769;IfcTextStyleTextModel;"<EPM-HTML>

<p><u>Definition from CSS1 (W3C Recommendation)</u>: The properties defined in the text model affect the visual presentation of characters, spaces, words, and paragraphs.</p>

<p>The <i>IfcTextStyleTextModel</i> combines all text style properties, that affect the presentation of a text literal within a given extent. It includes the spacing between characters and words, the horizontal and vertical alignment of the text within the planar box of the extent, decorations (like underline), transformations of the literal (like uppercase), and the height of each text line within a multi-line text block.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding CSS1 definitions are Text properties (word-spacing, letter-spacing, text-decoration, vertical-align, text-transform, text-align, text-indent, line-height).
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

</EPM-HTML>"
4783;IfcFillAreaStyle;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The style for filling visible curve segments, annotation fill areas or surfaces with tiles or hatches.</p>

<p>An <i>IfcFillAreaStyle</i> provides the style table for presentation information assigned to annotation fill areas or surfaces for hatching and tiling. The <i>IfcFillAreaStyle </i>defines hatches as model hatches, that is, the distance between hatch lines, or the curve patterns of hatch lines are given in model space dimensions (that have to be scaled using the target plot scale). The <i>IfcFillAreaStyle</i> allows for the following combinations of defining the style of hatching and tiling:</p>

<ul>
<li>Solid fill for areas and surfaces by only assigning <i>IfcColour</i> to the set of <i>FillStyles</i>. It then provides the background colour for the filled area or surface.</li>
</ul>

<blockquote> <blockquote><small>NOTE&nbsp; Color information of surfaces for rendering is assigned by using <i>IfcSurfaceStyle</i>, not by using <i>IfcFillAreaStyle</i>.</small></blockquote></blockquote>

<ul> 
<li>Vector based hatching for areas and surfaces based on a single row of hatch lines by assigning a single instance of <i>IfcFillAreaStyleHatching</i> to the set of <i>FillStyles</i>.</li> <ul> <li>If an instance of <i>IfcColour</i> is assigned in addition to the set of <i>FillStyles</i>, it provides the background colour for the hatching.</li> </ul> <li>Vector based hatching for areas and surfaces based on two (potentially crossing) rows of hatch lines by assigning two instances of <i>IfcFillAreaStyleHatching</i> to the set of <i>FillStyles.</i></li> 

<ul> <li>If an instance of <i>IfcColour</i> is assigned in addition to the set of <i>FillStyles</i>, it provides the background colour for the hatching.</li> </ul>
</ul>

<blockquote> <blockquote class=""note"">
NOTE&nbsp; Assigning more then two instances of <i>IfcFillAreaStyleHatching</i> to define three or more rows of hatch lines is not encouraged.
</blockquote> </blockquote>

<ul>
<li>Tiling for areas and surfaces by assigning a single instance of <i>IfcFillAreaStyleTiles</i> to the set of <i>FillStyles</i>.</li> <ul> <li>If an instance of <i>IfcColour</i> is assigned in addition to the set of <i>FillStyles</i>, it provides the background colour for the tiling.</li> </ul>
</ul>

<blockquote> <blockquote class=""change-ifc2x3"">
IFC2x3 NOTE&nbsp; The use of IfcFillAreaStyleTiles is discouraged., as its definition might change is future releases.
</blockquote></blockquote>

<ul>
<li>Externally defined hatch style by assigning a single instance of <i>IfcExternallyDefinedHatchStyle</i> to the set of <i>FillStyles</i>. 
  <ul><li>If an instance of <i>IfcColour</i> is assigned in addition to the set of <i>FillStyles</i>, it provides the background colour for the hatching.</li></ul>
</li>
</ul>

<p>Measures given to a hatch or tile pattern are given in global drawing length units.</p>

<blockquote class=""note"">
NOTE&nbsp; Global units are defined at the single <i>IfcProject</i> instance, given by <i>UnitsInContext:IfcUnitAssignment</i>, the same units are used for the geometric representation items and for the style definitions.
</blockquote>

<p>The measure values for hatch or tile pattern apply to the model space with a target plot scale provided for the correct appearance in the default plot scale. For different scale and projection dependent fill area styles a different instance of <i>IfcFillAreaStyle</i> needs to be used by <i>IfcPresentationStyleAssignment</i> for different <i>IfcGeometricRepresentationSubContext</i> dependent representations.</p>

<blockquote class=""note"">
NOTE&nbsp; the target plot scale is given by <i>IfcGeometricRepresentationSubContext.TargetScale</i>.
</blockquote>

<p>An <i>IfcFillAreaStyle</i> can be assigned to <i>IfcFillArea</i> via the <i>IfcPresentationStyleAssignment</i> through an intermediate <i>IfcStyledItem</i> or subtype <i>IfcAnnotationFillAreaOccurrence</i>.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: fill_area_style. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4793;IfcFillAreaStyleTiles;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The fill area style tiles defines a two dimensional tile to be used for the filling of annotation fill areas or other closed regions. The content of a tile is defined by the tile set, and the placement of each tile determined by the filling pattern which indicates how to place tiles next to each other. Tiles or parts of tiles outside of the annotation fill area or closed region shall be clipped at the of the area or region.</p> 

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: fill_area_style_tiles. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4797;IfcOneDirectionRepeatFactor;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A one time repeat factor is a vector used in the fill area style hatching and fill area style tiles entities for determining the origin of the repeated hatch line relative to the origin of the previous hatch line, Given the initial position of any hatch line, the one direction repeat factor determines two new positions according to the equation:</p> 

<blockquote> 
<p>I + k * R &nbsp;&nbsp;&nbsp;k <span style=""font-family:Symath"">X</span>{-1,1}</p>
</blockquote> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 name: one_direction_repeat_factor. Please refer to ISO/IS 10303-46:1994, p. 112 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4800;IfcTwoDirectionRepeatFactor;"<EPM-HTML>
	 
<p><u>Definition from ISO/CD 10303-46:1992</u>: A two direction repeat factor combines two vectors which are used in the fill area style tiles entity for determining the shape and relative location of tiles. Given the initial position of any tile, the two direction repeat factor determines eight new positions according to the equation:</p>

<blockquote>
		<p>k<sub>1</sub>* R<sub>1</sub> + k<sub>2</sub>* R<sub>2</sub>
		  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;k <span
		  style=""font-family:Symath"">X</span>{-1,1}&nbsp;<img
		  src=""figures/IfcFillAreaStyleTileSymbolWithStyle_Fig1.gif"" alt=""formula""
		  width=""100"" height=""30"" border=""0"" align=""middle""></p>
</blockquote> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 name: two_direction_repeat_factor. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history""> 
HISTORY New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4804;IfcFillAreaStyleTileSymbolWithStyle;"<EPM-HTML>

<p>The fill area style tile symbol with style is a symbol that is used as a tile within an annotated tiling.</p> 

<blockquote class=""note""> 
NOTE: The <I>IfcFillAreaStyleTileSymbolWithStyle</I> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&#151;Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation.
</blockquote> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 name: fill_area_style_tile_symbol_with_style. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote> 

</EPM-HTML>"
4806;IfcStyledItem;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The styled item is an assignment of style for presentation to a geometric representation item as it is used in a representation.</p>

<blockquote class=""note"">
NOTE &nbsp;Corresponding ISO 10303 name: styled_item. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<p>The <i>IfcStyledItem</i> holds presentation style information for products, either explicitly for an <i>IfcGeometricRepresentationItem</i> being part of an <i>IfcShapeRepresentation</i> assigned to a product, or by assigning presentation information to <i>IfcMaterial</i> being assigned as other representation for a product.</p>
<ul>
<li>If the <i>IfcStyledItem</i> is used within a reference from an <i>IfcProductDefinitionShape</i> then one <i>Item</i> shall be provided.</li>
<li>If the <i>IfcStyledItem</i> is used within a reference from an <i>IfcMaterialDefinitionRepresentation</i> then no <i>Item</i> shall be provided.</li>
</ul>

<blockquote class=""history"">
HISTORY &nbsp;New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x2"">
IFC2x2 Addendum 1 CHANGE&nbsp; The entity <i>IfcStyledItem</i> has been made non abstract and the attribute <i>Name</i> added.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE The attribute <i>Item</i> has been made optional, upward compatibility for file
based exchange is guaranteed.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE The subtype <i>IfcAnnotationOccurrence</i> and its subtypes are deleted. Use <i>IfcStyledItem</i> for all instantiations. The data type of <i>Styles</i> has been changed to <i>IfcStyleAssignmentSelect</i>
</blockquote>

<p class=""head-use"">Use Definition</p>

<p>Figure 293 illustrates use of <i>IfcStyledItem</i> for the two usage examples:</p>
<ul>
<li><small>As a presentation for a geometric representation item</small></li>
<li><small>As a presentation for a material definition</small></li>
</ul>
<blockquote class=""note"">NOTE&nbsp; The new <i>IfcStyleAssignmentSelect</i> allows the direct assignment styles, such as <i>IfcCurveStyle</i>, <i>IfcSurfaceStyle</i> without using the intermediate <i>IfcPresentationStyleAssignment</i></blockquote>

<table summary=""use diagram"">
<tr><td><img src=""figures/IfcStyledItem_fig-1.png"" alt=""2x4 example"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 293 &mdash; Styled item</p></td></tr>
</table>

</EPM-HTML>"
4814;IfcPresentationStyleAssignment;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The presentation style assignment is a set of styles which are assigned to styled items for the purpose of presenting these styled items.</p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 name: presentation_style_assignment. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in Release IFC2x2.
</blockquote>

</EPM-HTML>"
4825;IfcSymbolStyle;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The symbol style is the presentation style that indicates the presentation of annotation symbols.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 name: symbol_style. Please refer to ISO/IS 10303-46:1994, p. 124 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history""> 
HISTORY: New entity in Release IFC2x2.
</blockquote>

</EPM-HTML>"
4829;IfcSurfaceStyle;"<EPM-HTML> 

<p><i>IfcSurfaceStyle</i> is an assignment of one or many surface style elements to a surface, defined by subtypes of <i>IfcSurface</i>, <i>IfcFaceBasedSurfaceModel</i>, <i>IfcShellBasedSurfaceModel</i>, or by subtypes of <i>IfcSolidModel</i>. The positive direction of the surface normal relates to the positive side. In case of solids the outside of the solid is to be taken as positive side.</p> 

<blockquote class=""note"">
NOTE: The surface style is often referred to as material definition in rendering applications.
</blockquote>
 
<blockquote class=""note""> 
NOTE Corresponding ISO 10303 entity: surface_style_usage and surface_side_style. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard. The surface style definition in regard to support of rendering has been greatly expanded beyond the scope of ISO/IS 10303-46.
</blockquote> 

<blockquote class=""history"">
HISTORY New Entity in IFC 2.x.
</blockquote> 

</EPM-HTML>"
4847;IfcSurfaceStyleShading;"<EPM-HTML> 
	 
<p><u>Definition from ISO/CD 10303-46:1992</u>: The surface style rendering allows the realistic visualization of surfaces referring to rendering techniques based on the laws of physics and mathematics.</p> 

<p>The entity <i>IfcSurfaceStyleShading</i> allows for colour information used for shading, whereas subtypes provide data for more sophisticated rendering techniques. The surface colour is used for colouring or simple shading of the assigned surfaces.</p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 entity: surface_style_rendering. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard. No rendering method is defined for each surface style (such as constant, colour, dot or normal shading), therefore the attribute rendering_method has been omitted.
</blockquote>
 
<blockquote class=""history"">
HISTORY: New entity in IFC 2x.
</blockquote>

</EPM-HTML>"
4850;IfcSurfaceStyleRendering;"<EPM-HTML>

<p><i>IfcSurfaceStyleRendering</i> holds the properties for visualization related to a particular surface side style. </p> 

<p>It allows rendering properties to be defined by:</p> 
	 <ul> 
		<li>a transparency component (<i>Transparency</i> attribute)</li> 
		<li>a colour component (<i>SurfaceColour</i> attribute inherited from <i>IfcSurfaceStyleShading</i>)</li> 
		<li>a reflectance component, given either by 
		  <ul> 
			 <li>applying reflectance factors to the surface colour: 
				<ul> 
				  <li>diffuse component (<i>SurfaceColour * DiffuseFactor</i>)</li>				  
				  <li>transmission component (<I>SurfaceColour * TransmissionFactor</I>)</li> 
				  <li>diffuse transmission component (<i>SurfaceColour * DiffuseTransmissionFactor</i>)</li> 
				  <li>reflection component (<i>SurfaceColour * ReflectionFactor</i>)</li> 
				  <li>specular component (<i>SurfaceColour * SpecularFactor</i> attribute together with <i>SpecularHighlight</i>)</li> 
				</ul> </li> 
			 <li>explicitly defining such factors as colours (<i>DiffuseColour</i>, <i>TransmissionColour</i>, <i>DiffuseTransmissionColour</i>, <i>ReflectionColour</i> and <i>SpecularColour</i>)</li> 
		  </ul> </li> 
		<li>a displacement component, currently only given by a texture map with the TextureType = bump</li> 
		<li>a coverage component, currently only given by the alpha component of the texture map (2 or 4 component colour texture)</li> 
	 </ul> 

<blockquote class=""note"">
NOTE: The inherited attribute <I>SurfaceColour</I> is treated as the ambient colour and specifies how much ambient light from light sources this surface shall reflect. Ambient light is omnidirectional and depends only on the number of light sources, not their positions with respect to the surface.
</blockquote> 

<blockquote class=""note""> 
NOTE: If the reflectance method, as given by the <i>IfcReflectanceMethodEnum</i> is ""GLASS"", the transmission factor controls the level of transparency in the glass, In this case the transparency factor is interpreted as transmission factor.
</blockquote> 

<blockquote class=""note"">
NOTE: Both <I>Transparency</I> and <I>TransmissionColour</I> (or factor) are included, the following definitions apply:
		<ul> 
		  <li>Transparency is the ratio of the transmitted flux in a solid angle of 2 * PI sr (one hemisphere). It is a simple colour filtration that does not account for refraction.</li> 
		  <li>Transmission factor of a material is the ratio of transmitted flux in a given solid angle to the transmitted flux of a completely diffuse material with 100% transmission in the same solid angle. It is the portion of light that goes through the material and may be refracted.</li> 
		</ul>
</blockquote> 

<blockquote class=""note"">
NOTE: IFC 2x2 adds additional capability for presentation of physically accurate illuminance on surfaces. VRML type rendering and rendering based on ISO 10303-46 continues to be supported by a subset of the information. For reflectance equations and further information about the surface style properties and its processing, see:
		<ul> 
		  <li>ISO/IEC 14772-1: 1997: The Virtual Reality Modeling Language</li> 
		</ul>
</blockquote> 

<blockquote class=""note"">
NOTE: The definition of <i>IfcSurfaceStyleRenderingProperties</i> includes the definitions as found in ISO 10303-46:1994, in particular of:
		<ul> 
		  <li>surface_style_rendering_with_properties</li>
		  <LI>surface_style_rendering_ambient</li>
		  <LI>surface_style_rendering_ambient_diffuse</li>
		  <LI>surface_style_rendering_ambient_diffuse_specular</li>
		  <LI>surface_style_transparent</li>
		</ul>
</blockquote> 

<blockquote>In addition to the attributes as defined in ISO 10303-46, (ambient_reflectance, diffuse_reflectance, specular_reflectance, specular_exponent, and specular_colour), the current IFC definition adds other colours, reflectance factors and specular roughness.
</blockquote> 

<blockquote class=""history"">
HISTORY: New Entity in IFC 2x.
</blockquote>

</EPM-HTML>"
4879;IfcSurfaceStyleLighting;"<EPM-HTML> 

<p><i>IfcSurfaceStyleLighting</i> is a container class for properties for calculation of physically exact illuminance related to a particular surface style.</p>

<p>Figure 294 shows the reflection and transmission components from an incident ray. The sum of the components for reflection and transmission is a value of 1.0 denoting that the incident ray is completely decomposed into reflection and transmission components. Each value of reflection and transmission is therefore within the range 0.0 to 1.0.</p> 

<table>
<tr><td><img src=""figures/IfcSurfaceLightingProperties_Fig1.gif"" alt=""material reflection components"" width=""300"" height=""236"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 294 &mdash; Surface style lighting</p></td></tr>
</table>

<p>All these factors can be measured physically and are ratios for the red, green and blue part of the light. These properties are defined in the model as Type <i>IfcColorRGB</i> with a factor for each colour.</p> 

<blockquote class=""example""> 
EXAMPLE&nbsp; A green glass transmits only green light, so its transmission factor is 0.0 for red, between 0.0 and 1.0 for green and 0.0 for blue. A green surface reflects only green light, so the reflectance factor is 0.0 for red, between 0.0 and 1.0 for green and 0.0 for blue.
</blockquote> 

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC 2x2.
</blockquote>

</EPM-HTML>
"
4884;IfcSurfaceStyleWithTextures;"<EPM-HTML>

<p>The entity <em>IfcSurfaceStyleWithTextures</em> allows to include image textures in surface styles. These image textures can be applied repeating across the surface or mapped with a particular scale upon the surface.</p>

<p>The entity <em>IfcSurfaceStyleWithTextures</em> is part of the surface style table for presentation information assigned to surfaces for shading, rendering and lighting with textures. The mapping of the texture onto the surface or the solid is determined by the texture coordinates, in absense of an <em>IfcTextureCoordinate</em> assigned to each surface texture, a default mapping of the texture to the geometric face or surface applies.</p>

<p>Surface textures included in the <em>IfcSurfaceStyleWithTextures</em> are two dimensional map formats. They define 2D images that contain an array of colour values describing the texture. Depending on the number of <em>IfcSurfaceTextures</em> being included in the list of <em>Textures</em> the <em>IfcSurfaceStyleWithTextures</em> either describes a single texture, or a multi texture.</p>
<ul>
<li>single texture: a single surface texture is applied to the styled geometric item (entirely or partly) with optional repetition and texture transformation</li>
<li>multi texture: two or more surface textures are applied to the styled geometric item (entirely or partly) with optional repetition, texture transformation or texture coordinate mapping being specific for each texture.</li>
</ul>
<p><span style=""text-decoration:underline"">Informal proposition</span></p>
<ol>
<li>Only one instance of <em>IfcSurfaceStyleWithTextures</em> shall be referenced by an <em>IfcStyledItem</em> and be assigned to an <em>IfcGeometricRepresentationItem</em></li>
</ol>

<blockquote class=""note"">
NOTE&nbsp; The definitions of texturing within this standard have been developed in dependence on the texture component of X3D. See ISO/IEC 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1, 18 Texturing component for the definitions in the international standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; inverse attribute <em>HasTextureCoordinates</em> deleted.
</blockquote>

</EPM-HTML>"
4886;IfcSurfaceTexture;"<EPM-HTML>

<p>An <em>IfcSurfaceTexture</em> provides a 2-dimensional
image-based texture map. It can either be given by referencing an
external image file through an URL reference
(<em>IfcImageTexture</em>), including the image file as a blob
(long binary) into the data set (<em>IfcBlobTexture</em>), or by
explicitly including an array of pixels
(<em>IfcPixelTexture</em>).</p>
<p>The following definitions from ISO/IEC 19775-1 X3D Architecture
and base components (<a href=
""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>)
apply:</p>
<ul>
<li><span style=""font-size:smaller;color:blue"">Texture: An image
used in a texture map to create visual appearance effects when
applied to geometry nodes.</span></li>
<li><span style=""font-size:smaller;color:blue"">Texture map: A
texture plus the general parameters necessary for mapping the
texture to geometry.</span></li>
</ul>
<p>Texture are defined by 2D images that contain an array of colour
values describing the texture. The texture values are interpreted
differently depending on the number of components in the texture
and the specifics of the image format. In general, texture may be
described using one of the following forms:</p>
<ol>
<li>Intensity textures (one-component)</li>
<li>Intensity plus alpha opacity textures (two-component)</li>
<li>Full RGB textures (three-component)</li>
<li>Full RGB plus alpha opacity textures (four-component)</li>
</ol>
<blockquote class=""note"">
<p>NOTE&nbsp; Image formats specify an alpha opacity, not transparency (where alpha = 1 - transparency).</p>
</blockquote>

<p>Figure 295 illustrates the texture coordinate system.</p>

<table summary=""texture coordinate"">
<tr><td><img src=""figures/IfcSurfaceTexture_fig-1.png"" alt=""texture coordinates""></td></tr>
<tr><td><p class=""figure"">Figure 295 &mdash; Surface texture coordinates</p></td></tr>
</table>

<p>The following definitions from ISO/IEC 19775-1 X3D Architecture and base components (<a href=""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>) on texture coordinates apply:</p>
<ul>
<li><span style=""font-size:smaller;color:blue"">Texture maps are defined in a 2D coordinate system (s,&nbsp;t) that ranges from [0.0, 1.0] in both directions. The bottom edge of the image corresponds to the S-axis of the texture map, and left edge of the image corresponds to the T-axis of the texture map. The lower-left pixel of the image corresponds to s=0, t=0, and the top-right pixel of the image corresponds to s=1, t=1. Texture maps may be viewed as two dimensional colour functions that, given an <em>(s,&nbsp;t)</em> coordinate, return a colour value <em>colour(s,&nbsp;t)</em>.</span></li>
</ul>

<p>If multiple surface textures are included in the
<em>IfcSurfaceStyleWithTextures</em> applying them to a geometric
item, a mode and optional parameters can be included that blending
operations.</p>
<p>The <em>RepeatS</em> and <em>RepeatT</em> Boolean flags control
whether the texture map is repeated outside the [0.0, 1.0] texture
coordinate range, when applied to a geometric surface, or clamped
to lie within the [0.0, 1.0] range. The <em>TextureTransform</em>
applies a 2D non-uniform transformation to the texture before it is
applied to a geometric surface.</p>
<p>The following definitions from ISO/IEC 19775-1 X3D Architecture
and base components (<a href=
""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>)
apply:</p>
<ul>
<li><span style=""font-size:smaller;color:blue"">These parameters
support changes to the size, orientation, and position of textures
on shapes. Note that these operations appear reversed when viewed
on the surface of geometry. For example, a <i>scale</i> value of (2
2) will scale the texture coordinates and have the net effect of
shrinking the texture size by a factor of 2 (texture coordinates
are twice as large and thus cause the texture to repeat). A
translation of (0.5 0.0) translates the texture coordinates +.5
units along the S-axis and has the net effect of translating the
texture &minus;0.5 along the S-axis on the geometry's surface. A
rotation of &pi;/2 of the texture coordinates results in a
&minus;&pi;/2 rotation of the texture on the geometry.</span></li>
<li><span style=""font-size:smaller;color:blue"">The <i>center</i>
field specifies a translation offset in texture coordinate space
about which the <i>rotation</i> and <i>scale</i> fields are
applied. The <i>scale</i> field specifies a scaling factor in S and
T of the texture coordinates about the <i>center</i> point.
<i>scale</i> values shall be in the range (&minus;&infin;,&infin;).
The <i>rotation</i> field specifies a rotation in radians of the
texture coordinates about the <i>center</i> point after the scale
has been applied. A positive rotation value makes the texture
coordinates rotate counterclockwise about the centre, thereby
rotating the appearance of the texture itself clockwise. The
<i>translation</i> field specifies a translation of the texture
coordinates.</span><br>
<span style=""font-size:smaller"">The following conventions
apply:</span>
<ul>
<li style=""list-style-type:none""><span style=
""font-size:smaller"">center =
<em>TextureTransform.LocalOrigin</em>;<br>
rotation = <em>TextureTransform.Axis1</em><br>
scale S = <em>TextureTransform.Scale</em><br>
scale T = <em>TextureTransform.Scale2</em></span></li>
</ul>
</li>
</ul>

<blockquote class=""note"">
NOTE&nbsp; The definitions of texturing within this standard have been developed in dependence on the texture component of X3D. See ISO/IEC 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1, 18 Texturing component for the definitions in the international standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC 2x2.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Attribute TextureType replaces by <em>Mode</em>, attributes <em>Parameter</em> and <em>MapsTo</em> aded, new inverse attribute <em>UsedInStyle</em>.
</blockquote>

</EPM-HTML>"
4897;IfcPixelTexture;"<EPM-HTML>

<p>An <i>IfcPixelTexture</i> provides a 2D image-based texture map as an explicit array of pixel values (list of <em>Pixel</em> binary attributes). In contrary to the <i>IfcImageTexture</i> the <i>IfcPixelTexture</i> holds a 2 dimensional list of pixel color
(and opacity) directly, instead of referencing to an URL.</p>

<p>The following definitions from ISO/IEC 19775-1 X3D Architecture and base components (<a href=""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>) apply:</p>
<ul style=""list-style-type:disk;font-size:smaller;color:blue"">
<li>The PixelTexture node defines a 2D image-based texture map as an explicit array of pixel values (image field) and parameters controlling tiling repetition of the texture onto geometry.</li>
<li>Texture maps are defined in a 2D coordinate system (s, t) that ranges from 0.0 to 1.0 in both directions. The bottom edge of the pixel image corresponds to the S-axis of the texture map, and left edge of the pixel image corresponds to the T-axis of the texture map. The lower-left pixel of the pixel image corresponds to s=0.0, t=0.0, and the top-right pixel of the image corresponds to s = 1.0, t = 1.0.</li>
<li>The Image field specifies a single uncompressed 2-dimensional pixel image. Image fields contain three integers representing the width, height and number of components in the image, followed by width&times;height hexadecimal values representing the pixels in the image. Pixel values are limited to 256 levels of intensity (that is, 0x00-0xFF hexadecimal).
<ol>
<li>A one-component image specifies one-byte hexadecimal value representing the intensity of the image. For example, 0xFF is full intensity in hexadecimal (255 in decimal), 0x00 is no intensity (0 in decimal).</li>
<li>A two-component image specifies the intensity in the first
(high) byte and the alpha opacity in the second (low) byte.</li>
<li>Pixels in a three-component image specify the red component in the first (high) byte, followed by the green and blue components (for example, 0xFF0000 is red, 0x00FF00 is green, 0x0000FF is blue).</li>
<li>Four-component images specify the alpha opacity byte after red/green/blue (e.g., 0x0000FF80 is semi-transparent blue). A value of 00 is completely transparent, FF is completely opaque, 80 is semi-transparent.</li>
</ol>
</li>
<li style=""list-style: none; display: inline""><font size=""-1"">Note that alpha equals (1.0 -transparency), if alpha and transparency each range from 0.0 to 1.0.</font></li>
</ul>

<blockquote class=""history"">
HISTORY: New class in IFC2x2.
</blockquote>

</EPM-HTML>"
4907;IfcImageTexture;"<EPM-HTML>

<p>An <i>IfcImageTexture</i> provides a 2-dimensional texture that can be applied to a surface of an geometric item and that provides lighting parameters of a surface onto which it is mapped. The texture is provided as an image file at an external location for which an URL is provided.</p>

<p>The following definitions from ISO/IEC 19775-1 X3D Architecture and base components (<a href=""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>) apply:</p>
<ul style=""list-style-type:disk;font-size:smaller;color:blue"">
<li>The ImageTexture node defines a texture map by specifying an image file and general parameters for mapping to geometry.</li> 
<li>The texture is read from the URL specified by the url field. When the url field contains no [resolvable] values, texturing is disabled. Browsers shall support the JPEG and PNG (see ISO/IEC 15948) image file formats.</li>
<li>Texture nodes that require support for the PNG image format shall interpret the PNG pixel formats in the following way:
<ol type=""a"">
<li>Greyscale pixels without alpha or simple transparency are treated as intensity textures.</li>
<li>&gt;Greyscale pixels with alpha or simple transparency are treated as intensity plus alpha textures.</li>
<li>RGB pixels without alpha channel or simple transparency are treated as full RGB textures.</li>
<li>RGB pixels with alpha channel or simple transparency are treated as full RGB plus alpha textures.</li>
</ol>
</li>
<li>If the image specifies colours as indexed-colour (that is, palettes or colourmaps), the following semantics should be used (note that `greyscale' refers to a palette entry with equal red, green, and blue values):
<ol type=""a"">
<li>If all the colours in the palette are greyscale and there is no transparency chunk, it is treated as an intensity texture.</li>
<li>If all the colours in the palette are greyscale and there is a transparency chunk, it is treated as an intensity plus opacity texture.</li>
<li>&gt;If any colour in the palette is not grey and there is no transparency chunk, it is treated as a full RGB texture.</li>
<li>If any colour in the palette is not grey and there is a transparency chunk, it is treated as a full RGB plus alpha texture.</li>
</ol>
</li>
<li>Texture nodes that require support for JPEG files shall interpret JPEG files as follows:
<ol type=""a"">
<li>Greyscale files (number of components equals 1) are treated as intensity textures.</li>
<li>YCbCr files are treated as full RGB textures.</li>
<li>No other JPEG file types are required. It is recommended that other JPEG files are treated as a full RGB textures.</li>
</ol>
</li>
<li>Texture nodes that recommend support for GIF files shall follow the applicable semantics described above for the PNG format.</li>
</ul>

<p>The Uniform Resource Locator (URL) is a form of an URI and specified in <a href=""http://www.ietf.org/rfc/rfc1738.txt?number=1738"">RFC1738</a> by IETF. It supports resources located on a particular server being accessed by a particular protocol (usually http), and resources located at a local machine.</p>

<blockquote class=""note"">
NOTE&nbsp; Exchange files following the ifcZIP convention may include a sub directory structure for image resources to be stored together with the product data set.
</blockquote>

<blockquote class=""note"">
<p><span style=""font-size:smaller;color:blue"">NOTE&nbsp; The definitions of texturing within this standard have been developed in dependence on the texture component of X3D. See ISO/IEC 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1, 18 Texturing component for the definitions in the international standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC2x2.
</blockquote>

</EPM-HTML>"
4909;IfcExternallyDefinedSurfaceStyle;"<EPM-HTML>

<p><i>IfcExternallyDefinedSurfaceStyle</i> is a definition of a surface style through referencing an external source, such as a material library for rendering information.</p>

<blockquote class=""note"">
NOTE&nbsp; In order to achieve expected results, the externally defined surface style should normally only be given in addition to an explicitly defined surface styles.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE &nbsp;The spelling has been corrected from IfcExternallyDefinedSufaceStyle with no upward compatibility.
</blockquote> 

</EPM-HTML>"
4910;IfcExternallyDefinedHatchStyle;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The externally defined hatch style is an entity which makes an external reference to a hatching style.</p>

<blockquote class=""note"">
NOTE: The allowable values for the name source and item reference, by which the externally defined hatch style is identified, need to be determined by implementer agreements.
</blockquote>

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 name: fill_style_select. Please refer to ISO/IS 10303-46:1994 for
the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4911;IfcBlobTexture;"<EPM-HTML>

<p>An <i>IfcBlobTexture</i> provides a 2-dimensional distribution of the lighting parameters of a surface onto which it is mapped. The texture itself is given as a single binary blob, representing the content of a pixel format file. The file format of the pixel file is given by the <i>RasterFormat</i> attribute and allowable formats are guided by where rule <i>SupportedRasterFormat</i>.</p>

<blockquote class=""note"">
NOTE&nbsp; Toolbox specific implementations of the binary datatype may restrict the maximum length of the binary blob to capture the raster file content.
</blockquote>

<p>For interpretation of the texture nodes see <i>IfcImageTexture</i> definition.</p>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC2x3.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Data type of <i>RasterCode</i> has been corrected to BINARY.
</blockquote>

</EPM-HTML>"
4916;IfcSurfaceStyleRefraction;"<EPM-HTML>

<p><i>IfcSurfaceStyleRefraction</i> extends the surface style lighting, or the surface style rendering definition for properties for calculation of physically exact illuminance by adding seldomly used properties. Currently this includes the refraction index (by which the light ray refracts when passing through a prism) and the dispersion factor (or Abbe constant) which takes into account the wavelength dependency of the refraction.</p>

<blockquote class=""note"">
NOTE: If such refraction properties are used, the <i>IfcSurfaceStyle</i> should include within its set of <i>Styles</i> (depending on whether rendering or lighting is used) an instance of <i>IfcSurfaceStyleLighting</i> and <i>IfcSurfaceStyleRefraction</i>, or an instance of <i>IfcSurfaceStyleRendering</i> and <i>IfcSurfaceStyleRefraction</i>.
</blockquote> 

<blockquote class=""history"">
HISTORY: New entity in IFC 2x2.
</blockquote>

</EPM-HTML>"
4925;IfcCurveStyleFont;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A curve style font combines several curve style font pattern entities into a more complex pattern. The resulting pattern is repeated along the curve.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 name: curve_style_font. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4928;IfcCurveStyleFontPattern;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A curve style font pattern is a pair of visible and invisible curve segment length measures in presentation area units.</p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 name: curve_style_font_pattern. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x2.
</blockquote> 

</EPM-HTML>"
4932;IfcCurveStyleFontAndScaling;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: A curve style font and scaling is a curve style font and a scalar factor for that font, so that a given curve style font may be applied at various scales.</p>

<p>The <i>IfcCurveStyleFontAndScaling</i> allows for the reuse of the same curve style definition in several sizes. The definition of the <i>CurveFontScale</i> is the scaling of a base curve style pattern to be used as a new or derived curve style pattern.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>CurveFontScale</i> should not be mixed up with the target plot scale.
</blockquote>

<p>An example for <i>IfcCurveStyleFontAndScaling</i> is the sizing of a basic curve style dash pattern 'dash' (visible 0.01m, invisible 0.005m) into 'dash large' with&nbsp;<i>CurveFontScale</i> = 2 (resulting in&nbsp;visible 0.02m, invisible 0.01m), and into 'dash small'&nbsp;with&nbsp;<i>CurveFontScale</i> = 0.5 (resulting in&nbsp;visible 0.005m, invisible 0.0025m).</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: curve_style_font_and_scaling. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4941;IfcTextLiteral;"<EPM-HTML>

<p>The text literal is a geometric representation item which describes a text string using a string literal and additional position and path information.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcTextLiteral</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&mdash;Product data representation and exchange.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: text_literal. Please refer to ISO/IS 10303-46:1994 for the
final definition of the formal standard. The attributes font and alignment have been removed as those should be handled by the text style.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The <i>IfcTextLiteral</i> has been changed by removing <i>Font</i> and <i>Alignment</i>.
</blockquote>

</EPM-HTML>"
4946;IfcAnnotationFillArea;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: An annotation fill area is a set of curves that may be filled with hatching, colour or tiling. The annotation fill are is described by boundaries which consist of non-intersecting, non-self-intersecting closed curves. These curves form the boundary of planar areas to be filled according to the style for the annotation fill area.</p>

<blockquote class=""note"">
NOTE: A curve that is not surrounded by any other curve is a border between an unfilled area on the outside and a filled area on the inside. Another curve may surround an unfilled area if it is surrounded by another curve whose inside is a filled area.
</blockquote>

<p>Figure 300 (from ISO 10303-46) illustrates annotation fill area.</p>
<table>
<tr><td><img src=""figures/IfcAnnotationFillArea.gif"" alt=""annotation fill area"" border=""0"" height=""200"" width=""350""></td></tr>
<tr><td><p class=""figure"">Figure 300 &mdash; Annotation fill area</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: annotation_fill_area. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<p>The <i>IfcAnnotationFillArea</i> defines an area by a definite <i>OuterBoundary</i>, that might include <i>InnerBoundaries</i>. The areas defined by the <i>InnerBoundaries</i> are excluded from applying the fill area style.</p>

<p>Informal Proposition:</p>
<ol>
  <li>Any curve that describes an inner boundary shall not intersect with, nor include, another curve defining an inner boundary.</li>
  <li>The curve defining the outer boundary shall not intersect with any curve defining an inner boundary, nor shall it be surrounded by a curve defining an inner boundary.</li>
</ol>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The two attributes <i>OuterBoundary</i> and <i>InnerBoundaries</i> are added and replace the previous single boundary.
</blockquote>

</EPM-HTML>"
4949;IfcDefinedSymbol;"<EPM-HTML>

<p>A defined symbol is a symbolic representation that gets its shape information by an established convention, either through a predefined symbol, or an externally defined symbol.</p>

<blockquote class=""note"">
NOTE: The <i>IfcDefinedSymbol</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&#151;Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation.
</blockquote>
 
<blockquote> 
NOTE Corresponding ISO 10303 name: defined_symbol. The target attribute used the 2d Cartesian transformation operator, including the non-uniform subtype, which is available in IFC (instead of the symbol_target). Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4955;IfcPreDefinedSymbol;"<EPM-HTML>

<p>A predefined symbol is a symbol that gets its shape information by a conforming name that is specified within subtypes of the entity.</p>

<blockquote class=""note"">
NOTE: The <I>IfcPreDefinedSymbol</I> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&#151;Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation.
</blockquote>

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 name: pre_defined_symbol. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4956;IfcExternallyDefinedSymbol;"<EPM-HTML>
	 
<p>An externally defined symbol is a symbol that gets its shape information by an agreed reference to an external source.</p>

<blockquote class=""note"">
NOTE: The allowable symbol names and sources have to be established by implementers agreements.</blockquote>

<blockquote class=""note"">
NOTE: The <I>IfcExternallyDefinedSymbol</I> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&#151;Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation.
</blockquote> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 name: externally_defined_symbol. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
4957;IfcTextureCoordinate;"<EPM-HTML>

<p>The <em>IfcTextureCoordinate</em> a an abstract supertype of the different kinds to apply texture coordinates to geometries. For vertex based geometries an explicit assignment of 2D texture vertices to the 3D geometry points is supported by the subtype <em>IfcTextureMap</em>, in addition there can be a procedural description of how texture coordinates shall be applied to geometric items. If no <em>IfcTextureCoordinate</em> is provided for the <em>IfcSurfaceTexture</em>, the default mapping shall be used.</p>

<blockquote>
<p><span style=""font-size:smaller"">See relevant subtypes of <em>IfcGeometricRepresentationItem</em> for default texture mapping description.</span></p>
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; The definitions of texturing within this standard have been developed in dependence on the texture component of X3D. See ISO/IEC 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1, 18 Texturing component for the definitions in the international standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The attribute Texture is deleted.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The inverse attribute AnnotatedSurface is deleted, and the inverse <em>AppliesTextures</em> is added.
</blockquote>

</EPM-HTML>"
4961;IfcTextureCoordinateGenerator;"<EPM-HTML>

<p>The <em>IfcTextureCoordinateGenerator</em> describes a procedurally defined mapping function with input parameter to map 2D texture coordinates to 3D geometry vertices. The allowable <em>Mode</em> values and input <em>Parameter</em> need to be agreed upon in view definitions and implementer agreements.</p>

<blockquote>
<p><span style=""font-size:smaller"">It is recommended to use the texture coordinate generation modes as defined in X3D.</span></p>
</blockquote>

<p>The following definitions from ISO/IEC 19775-1 X3D Architecture and base components (<a href=
""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>) apply:</p>
<ul style=""list-style-type:disk;font-size:smaller;color:blue"">
<li>The TextureCoordinateGenerator supports the automatic generation of texture coordinates for geometric shapes.</li>
<li>The mode field describes the algorithm used to compute texture coordinates.
<ul>
<li>SPHERE,</li>
<li>CAMERASPACENORMAL,</li>
<li>CAMERASPACEPOSITION,</li>
<li>CAMERASPACEREFLECTIONVECTOR,</li>
<li>SPHERE-LOCAL,</li>
<li>COORD,</li>
<li>COORD-EYE,</li>
<li>NOISE,</li>
<li>NOISE-EYE,</li>
<li>SPHERE-REFLECT,</li>
<li>SPHERE-REFLECT-LOCAL</li>
</ul>
</li>
</ul>

<blockquote class=""note"">
NOTE&nbsp; The definitions of texturing within this standard have been developed in dependence on the texture component of X3D. See ISO/IEC 19775-1.2:2008 X3D Architecture and base components Edition 2, Part 1, 18 Texturing component for the definitions in the international standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x2"">
IFC2x2 Addendum 2 CHANGE&nbsp; The attribute Texturehas been deleted.
</blockquote>

</EPM-HTML>"
4964;IfcTextureMap;"<EPM-HTML> 

<p>An <i>IfcTextureMap</i> provides the mapping of the
2-dimensional texture coordinates to the surface onto which it is
mapped. It is used for mapping the texture to surfaces of vertex
based geometry models, such as</p>
<ul>
<li><i>IfcFacetedBrep</i></li>
<li><i>IfcFacetedBrepWithVoids</i></li>
<li><i>IfcFaceBasedSurfaceModel</i></li>
<li><i>IfcShellBasedSurfaceModel</i></li>
</ul>
<p>The <i>IfcTextureMap</i> has a list of <i>TextureVertex</i>,
that corresponds to the points of the face bound of the vertex
based geometry item. The corresponding pair of lists is:</p>
<ol>
<li>the list of <i>Polygon</i> of type <i>IfcCartesianPoint</i>,
and</li>
<li>the list of <i>Vertices</i> of type
<i>IfcTextureVertex</i>.</li>
</ol>
<p>Each <i>IfcTextureVertex</i> (given as S, T coordinates of the
2-dimension texture coordinate system) corresponds to the geometric
coordinates of the <i>IfcCartesianPoint</i> (given as 3-dimension
X, Y, and Z coordinates within the object coordinate system of the
geometric item).</p>
<p>The following definitions from ISO/IEC 19775-1 X3D Architecture
and base components (<a href=
""http://www.web3d.org/x3d/specifications/"">X3D Specification</a>)
apply:</p>
<ul style=""list-style-type:disk;font-size:smaller;color:blue"">
<li>The TextureCoordinate node is a geometry property node that
specifies a set of 2D texture coordinates used by vertex-based
geometry nodes to map textures to vertices.</li>
</ul>
<blockquote>
<p><span style=""font-size:smaller"">NOTE&nbsp; In contrary to the
X3D vertext based geometry, for example IndexedFaceSet and
ElevationGrid, the vertext based geometry in IFC may include inner
loops. The areas of inner loops have to be cut-out from the texture
applied to the outer loop.</span></p>
</blockquote>

<p>Figure 301 illustrates applying a texture map to a vertex based geometry.</p>

<table summary=""texture map use"">
<tr><td><img src=""figures/IfcTextureMap_fig-1.png"" width=""550"" height=""600"" alt=""IfcTextureMap_fig-1.png 35,3 KB""></td></tr>
<tr><td><p class=""figure"">Figure 301 &mdash; Texture map</p></td></tr>
</table>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The attribute Texture is deleted, and the attribute TextureMaps is added.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The attribute TextureMap is replaced by <em>Vertices</em>, and the attribute <em>AppliedTo</em> is added.
</blockquote>

<p><span style=""text-decoration:underline"">Informal propositions</span>:</p>
<ol>
<li>The <i>FaceBound</i> referenced in <i>AppliedTo</i> shall be used by the vertex based geometry, to which this texture map is assigned to by through the <i>IfcStyledItem</i>.</li>
</ol>

</EPM-HTML>"
4967;IfcTextureVertex;"<EPM-HTML>

<p>An <i>IfcTextureVertex</i> is a list of 2 (S, T) texture coordinates. </p>

<p>The following additional definitions from <a class=""int-ref"" href=""../../bibliography.htm#iso-19775"">ISO 19775</a> apply:</p>

<blockquote>
  <p>Each vertex-based geometry node uses a set of 2D texture
coordinates that map textures to vertices. Texture map values (
ImageTexture, PixelTexture) range from [0.0, 1.0] along the S-axis and
T-axis. However, texture coordinate values may be in the range
(-&infin;,&infin;). Texture coordinates identify a location
(and thus a
colour value) in the texture map. The horizontal coordinate S is
specified first, followed by the vertical coordinate T. If the texture
map is repeated in a given direction (S-axis or T-axis), a texture
coordinate C (s or t) is mapped into a texture map that has N pixels in
the given direction as follows: </p>
  <blockquote>
    <pre><b>Texture map location = (C - floor(C)) &times; N<br>			 </b></pre>
  </blockquote>
  <p>If the texture map is not
repeated, the texture coordinates are
clamped to the 0.0 to 1.0 range as follows: </p>
  <blockquote>
    <pre><b>Texture map location = N,     if C &gt; 1.0,<br>                     = 0.0,   if C &lt; 0.0,<br>                     = C &times; N, if 0.0 &le; C &le; 1.0.</b>
    </pre>
  </blockquote>
  <p>Texture coordinates may be transformed (scaled, rotated, translated) by supplying a TextureTransform as a component of the texture's definition. </p>
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC 2x2.
</blockquote>

</EPM-HTML>"
4969;IfcTextLiteralWithExtent;"<EPM-HTML>

<p>The text literal with extent is a text literal with the additional explicit information of the planar extent (or surrounding text box). An alignment attribute defines, how the text box is aligned to the placement and how it may expand.</p>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcTextLiteralWithExtent</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration&mdash;Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation. </blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: text_literal_with_extent. Please refer to ISO/IS 10303-46:1994 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE &nbsp;The <i>IfcTextLiteralWithExtent</i> has been changed by adding <i>BoxAlignment</i>.
</blockquote>

</EPM-HTML>"
4981;IfcLightSource;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The light source entity is determined by the reflectance specified in the surface style rendering. Lighting is applied on a surface by surface basis: no interactions between surfaces such as shadows or reflections are defined.</p> 

<blockquote class=""note""> 
NOTE: Corresponding STEP entity: light_source. Please refer to ISO/IS 10303-46:1994, p. 31 for the final definition of the formal standard. 
</blockquote> 
	 
<blockquote class=""note"">
NOTE: In addition to the attributes as defined in ISO10303-46 the following additional properties from ISO/IEC 14772-1:1997 (VRML) are added: <I>ambientIntensity</I> and <I>Intensity</I>. The attribute <I>Name</I> has been added as well (as it is not inherited via representation_item).
</blockquote> 

<blockquote class=""history"">
HISTORY: This is a new Entity in IFC 2x, renamed and enhanced in IFC2x2.
</blockquote>

</EPM-HTML>"
4990;IfcLightSourceAmbient;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-46:1992</U>: The light source ambient entity is a subtype of light source. It lights a surface independent of the surface's orientation and position.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: light_source_ambient. Please refer to ISO/IS 10303-46:1994, p. 31 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""note"">
NOTE: In addition to the attributes as defined in ISO 10303-46 the additional property from ISO/IEC 14772-1:1997 (VRML) <I>AmbientIntensity</I> is inherited from the supertype.
</blockquote> 

<blockquote class=""history"">
HISTORY: This is a new entity in IFC 2x, renamed and enhanced in IFC2x2.
</blockquote>

</EPM-HTML>"
4991;IfcLightSourceDirectional;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</U>: The light source directional is a subtype of light source. This entity has a light source direction. With a conceptual origin at infinity, all the rays of the light are parallel to this direction. This kind of light source lights a surface based on the surface's orientation, but not position.</p> 

<p><u>Definition from ISO/IEC 14772-1:1997</u>: The directional light node defines a directional light source that illuminates along rays parallel to a given 3-dimensional vector. Directional light nodes do not attenuate with distance. Directional light nodes are specified in the local coordinate system and are affected by ancestor transformations.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: light_source_directional. Please refer to ISO/IS 10303-46:1994, p. 32 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""note"">
NOTE: In addition to the attributes as defined in ISO 10303-46 the additional property from ISO/IEC 14772-1:1997 (VRML) <I>AmbientIntensity</I> and <I>Intensity</I> are inherited from the supertype.
</blockquote> 

<blockquote class=""history"">
HISTORY: This is a new entity in IFC 2x, renamed and enhanced in IFC2x2.
</blockquote>

</EPM-HTML>"
4993;IfcLightSourcePositional;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The light source positional entity is a subtype of light source. This entity has a light source position and attenuation coefficients. A positional light source affects a surface based on the surface's orientation and position.</p> 

<p><u>Definition from ISO/IEC 14772-1:1997</u>: The Point light node specifies a point light source at a 3D location in the local coordinate system. A point light source emits light equally in all directions; that is, it is omnidirectional. Point light nodes are specified in the local coordinate system and are affected by ancestor transformations. </p> 

<p>Point light node's illumination falls off with distance as specified by three attenuation coefficients. The attenuation factor is </p> 

<blockquote><small>
1/max(attenuation[0] + attenuation[1] &times; r + attenuation[2] &times; r 2 , 1), 
</small></blockquote> 

<p>where r is the distance from the light to the surface being illuminated. The default is no attenuation. An attenuation value of (0, 0, 0) is identical to (1, 0, 0). Attenuation values shall be greater than or equal to zero. </p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: light_source_positional. Please refer to ISO/IS 10303-46:1994, p. 32 for the final definition of the formal standard.
</blockquote>

<blockquote class=""note"">
NOTE: In addition to the attributes as defined in ISO10303-46 the additional property from ISO/IEC 14772-1:1997 (VRML) <I>Radius</I> and <I>QuadricAttenuation</I> are added to this subtype and the <I>AmbientIntensity</I> and <I>Intensity</I> are inherited from the supertype.
</blockquote> 

<blockquote class=""history"">
HISTORY: This is a new entity in IFC 2x, renamed and enhanced in IFC2x2.
</blockquote> 

</EPM-HTML>"
5000;IfcLightSourceSpot;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-46:1992</u>: The light source spot entity is a subtype of light source. Spot light source entities have a light source colour, position, direction, attenuation coefficients, concentration exponent, and spread angle. If a point lies outside the cone of influence of a light source of this type as determined by the light source position, direction and spread angle its colour is not affected by that light source.</p> 

<blockquote class=""note""> 
NOTE&nbsp; The <i>IfcLightSourceSpot</i> adds the <i>BeamWidthAngle</i> which defines the inner cone in which the light source emits light at uniform full intensity. The light source's emission intensity drops off from the inner solid angle (<i>BeamWidthAngle</i>) to the outer solid angle (<i>SpreadAngle</i>).
</blockquote> 

<p><u>Definition from ISO/IEC 14772-1:1997</u>: The Spot light node defines a light source that emits light from a specific point along a specific direction vector and constrained within a solid angle. Spot lights may illuminate geometry nodes that respond to light sources and intersect the solid angle defined by the Spot light. Spot light nodes are specified in the local coordinate system and are affected by ancestors' transformations.</p> 

<p>Figure 304 (from VRML97) shows the definition of spot light.</p> 

<table>
<tr><td><img src=""figures/IfcLightSourceSpot_Fig1.gif"" alt=""spot light"" align=""bottom"" width=""450"" height=""350"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 304 &mdash; Light source spot</p></td></tr>
</table>

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: light_source_spot. Please refer to ISO/IS 10303-46:1994, p. 33 for the final definition of the formal standard.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; In addition to the attributes as defined in ISO10303-46 the additional property from ISO/IEC 14772-1:1997 (VRML) <i>Radius</i>, <i>BeamWidth</i>, and <i>QuadricAttenuation</i> are added to this subtype and the <i>AmbientIntensity</i> and <i>Intensity</i> are inherited from the supertype.
</blockquote> 

<blockquote class=""history"">
HISTORY&nbsp; This is a new entity in IFC 2x, renamed and enhanced in IFC2x2.
</blockquote>

</EPM-HTML>"
5005;IfcLightSourceGoniometric;"<EPM-HTML> 

<p><i>IfcLightSourceGoniometric</i> defines a light source for which exact lighting data is available. It specifies the type of a light emitter, defines the position and orientation of a light distribution curve and the data concerning lamp and photometric information.</p> 

<p>Figure 303 shows an example of a light emitter having two light sources (of type <I>IfcLightSourceGoniometric</I>).</p> 

<table>
<tr><td><img src=""figures/IfcLightSourceGoniometric_Fig1.gif"" alt=""Example"" width=""587"" height=""366"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 303 &mdash; Light source goniometric</p></td></tr>
</table>


<blockquote class=""history""> 
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
5027;IfcLightIntensityDistribution;"<EPM-HTML>

<p><i>IfcLightIntensityDistribution</i> defines the the luminous intensity of a light source that changes according to the direction of the ray. It is based on some standardized light distribution curves, which are defined by the <i>LightDistributionCurve</i> attribute.</p> 

<blockquote class=""history"">
New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
5035;IfcLightDistributionData;"<EPM-HTML> 

<p><i>IfcLightDistributionData</i> defines the luminous intensity of a light source given at a particular main plane angle. It is based on some standardized light distribution curves; the <i>MainPlaneAngle</i> is either the</p> 

<ul> 
<li>A angle; if the <i>IfcLightDistributionCurveEnum</i> is set to TYPE_A</li> 
<li>B angle; if the <i>IfcLightDistributionCurveEnum</i> is set to TYPE_B</li> 
<li>C angle; if the <i>IfcLightDistributionCurveEnum</i> is set to TYPE_C</li> 
</ul> 

<p>For each <i>MainPlaneAngle</i> (considered as being the row of a table) a list of <i>SecondaryPlaneAngle'</i>s are given (considered to be the columns of a table). They are either the:</p> 

<ul> 
<li>&#945; angle; if the <i>IfcLightDistributionCurveEnum</i> is set to TYPE_A</li> 
<li>&#946; angle; if the <i>IfcLightDistributionCurveEnum</i> is set to TYPE_B</li> 
<li>&#947; angle; if the <I>IfcLightDistributionCurveEnum</I> is set to TYPE_C</li> 
</ul> 

<p>For each pair of <i>MainPlaneAngle</i> and <i>SecondaryPlaneAngle</i> the <i>LuminousIntensity</i> is provided (the unit is given by the <I>IfcUnitAssignment</I> referring to the LuminousIntensityDistributionUnit, normally cd/klm).</p> 

<blockquote class=""history""> 
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
5039;IfcPresentationLayerAssignment;"<EPM-HTML>

<p>The presentation layer assignment provides the layer name (and optionally a description and an identifier) for a collection of geometric representation items. The <i>IfcPresentationLayerAssignment</i> corresponds to the term ""CAD Layer"" and is used mainly for grouping and visibility control.</p>

<blockquote class=""note"">
NOTE&nbsp; The use of presentation layer shall be restricted to simple grouping and displaying purposes.
</blockquote>

<p>Visibility and access control and layer style assignment (colour, line style, line width) is handled by the subtype <i>IfcPresentationLayerAssignmentWithStyle</i>.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: presentation layer assignment. Please refer to ISO/IS 10303-46:1994, p. 36 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<p class=""use-head"">Attribute use definition</p>

<p>Figure 305 illustrates assignment of items by shape representation or representation item. The set of <em>AssignedItems</em> can either include a whole shape representation, or individual geometric representation items. If both, the <em>IfcShapeRepresentation</em> has a layer assignment, and an individual geometric representation item in the set of <em>IfcShapeRepresentation</em>.Items, then the layer assignment of the <em>IfcGeometricRepresentationItem</em> overides the layer assignment of the <em>IfcShapeRepresentation</em>.</p>

<table summary=""overriding of layer assignment"">
<tr><td valign=""top""><img src=""figures/IfcPresentationLayerAssignment-fig1.png"" alt=""instantiation diagram""></td></tr>
<tr><td><p class=""figure"">Figure 305 &mdash; Presentation layer assignment</p></td></tr>
</table>

</EPM-HTML>"
5046;IfcPresentationLayerWithStyle;"<EPM-HTML>

<p>An <i>IfcPresentationLayerAssignmentWithStyle</i> extends the presentation layer assignment with capabilities to define visibility control, access control and common style information.</p>

<p>The visibility control allows to define a layer to be either 'on' or 'off', and/or 'frozen' or 'not frozen'. The access control allows to block graphical entities from manipulations by setting a layer to be either 'blocked' or 'not blocked'. Common style information can be given to the layer.</p>

<blockquote class=""note"">
NOTE &nbsp;Style information assigned to layers is often restricted to 'layer colour', 'curve font', and/or 'curve width'. These styles are assigned by using the <i>IfcCurveStyle</i> within the <i>LayerStyles</i>.
</blockquote>

<blockquote class=""note"">
NOTE: If a styled item is assigned to a layer using the <i>IfcPresentationLayerAssignmentWithStyle</i>, it inherits the style information from the layer. In this case, it should omit its own style information. If the styled item has style information assigned (such as by <i>IfcCurveStyle</i>, <i>IfcFillAreaStyle</i>, <i>IfcTextStyle</i>, <i>IfcSurfaceStyle</i>, <i>IfcSymbolStyle</i>), then it overrides the style provided by the <i>IfcPresentationLayerAssignmentWithStyle</i>.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; The <i>IfcPresentationLayerAssignmentWithStyle</i> extends the presentation_layer_assignment entity as defined in ISO/IS 10303-46:1994, p. 36.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE &nbsp;The attributes have been modified without upward compatibility.
</blockquote>

</EPM-HTML>"
5056;IfcParameterizedProfileDef;"<EPM-HTML>

<p>The parameterized profile definition
defines a 2D position coordinate system to which the parameters of the
different profiles relate to. All profiles are defined centric to the
origin of the position coordinate system, or more specific, the origin
[0.,0.] shall be in the center of the bounding box of the profile.</p>

<p>The <i>Position</i> attribute of <i>IfcParameterizedProfileDef</i>
is used to position the profile within the XY plane of the underlying
coordinate system of the swept surface geometry, the swept area
solid or the sectioned spine. It can be used to position the profile at
any point which becomes the origin [0.,0.,0.] of the extruded
or rotated surface or solid.</p>

<p>The <i>Position</i> attribute should not be used if the transformation
can be specified in a containing object instead.  In particular, this
applies if the <i>IfcParameterizedProfileDef</i> is referenced as
<i>SweptArea</i> in subtypes of <i>IfcSweptAreaSolid</i> or as
<i>CrossSections</i> in <i>IfcSectionedSpine</i>.</p>

<p>Several subtypes of <i>IfcParameterizedProfileDef</i> provide
shape parameters which are optional. Sending systems should always
provide values for these parameters if possible. If these parameters
are left unspecified, receiving systems may retrieve values for them
by external reference (if a reference to an external document or library
is given; see guidance at <i>IfcProfileDef</i>), or estimate them, or
simply assume zero values.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x"">
IFC2x Platform CHANGE&nbsp; The <i>IfcParameterizedProfileDef</i>
is introduced as an intermediate new abstract entity that unifies the
definition and usage of the position coordinate system for all
parameterized profiles. The Position attribute has been removed at all
subtypes (like <i>IfcRectangleProfileDef</i>, <i>IfcCircleProfileDef</i>,
etc.).
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; All profile origins are now in the center
of the bounding box.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; <i>Position</i> attribute made optional (default: identity transformation).<br>
Several radius parameters in subtypes have been changed from optional <i>IfcPositiveLengthMeasure</i> (assumed default: 0.) to optional <i>IfcNonNegativeLengthMeasure</i> (default: unspecified).  This change allows to explicitly specify zero radius.  Sending systems shall export 0. values if parameters are known to be 0.<br>
Subtypes <i>IfcCraneRailAShapeProfileDef</i> and <i>IfcCraneRailFShapeProfileDef</i> deleted.  Rail profiles shall be modeled as <i>IfcArbitraryClosedProfileDef</i> or as <i>IfcAsymmetricIShapeProfileDef</i> together with appropriate external reference.
</blockquote>

</EPM-HTML>"
5068;IfcProfileDef;"<EPM-HTML>

<p><i>IfcProfileDef</i>
is the supertype of all definitions of standard and arbitrary profiles
within IFC. It is used to define a standard set of commonly used
section profiles by their parameters or by their explicit curve geometry.</p>

<ul>
  <li>Parameterized profiles are 2D primitives, which are used within the industry to describe cross
  sections by a description of its parameters.</li>
  <li>Arbitrary profiles are cross
  sections defined by an outer boundary as bounded curve, which may also
  include holes, defined by inner boundaries.</li>
  <li>Derived profiles, based on a
  transformation of a parent profile, are also part of the profile
  definitions available.</li>
  <li>In addition composite
  profiles can be defined, which include two or more profile definitions
  to define the resulting profile.</li>
</ul>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 1.5, the capabilities have been extended in IFC Release 2x.
Profiles can now support swept surfaces and swept area solids with
inner boundaries. It had been renamed from IfcAttDrivenProfileDef.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Changed from ABSTRACT to non-abstract for uses which do not
require an explicitly defined geometry.  Added inverse attributes <i>HasProperties</i> and <i>HasExternalReference</i>.
</blockquote>


<p><b>Use in material association</b></p>

<p>Beams, columns, and similarly shaped building elements and their type objects may
be associated with a section profile definition, combined with material definition,
by means of <i>IfcRelAssociatesMaterial</i> together with <i>IfcMaterialProfileSet</i>
and <i>IfcMaterialProfileSetUsage</i>. This way, building elements and element types
with same section and material can share a common section profile definition and
association.</p>

<p>The profile definition in material association is required to be consistent with
shape representations of the respective building elements.</p>

<p>A higher-level description of spatial aligment of the section profile of a member
(such as centered, bottom-left, in the geometric centroid, and more) can be provided
within <i>IfcMaterialProfileSetUsage</i> by means of a cardinal point reference.
This can be used redundant to geometric data in order to convey design intent.</p>


<p><b>Use in shape models</b></p>

<p>Profile definitions are used within the geometry and geometric model
resource to create either swept surfaces, swept area solids, or
sectioned spines.</p>

<p>The purpose of the profile
definition within the swept surfaces or swept area solids is to define
a uniform cross section being swept:</p>

<ul>
  <li>along a line (extrusion) using <i>IfcSurfaceOfLinearExtrusion</i> or <i>IfcExtrudedAreaSolid</i></li>
  <li>along a circular arc (revolution) using <i>IfcSurfaceOfRevolution</i> or <i>IfcRevolvedAreaSolid</i></li>
  <li>along a directrix lying on a reference surface using <i>IfcSurfaceCurveSweptAreaSolid</i></li>
</ul>

<p>The purpose fo the profile
definition within the sectioned spine is to define a varying cross
sections at several positions along a spine curve. The subtype <i>IfcDerivedProfileDef</i>
is particularly suited to provide the consecutive profiles to be based
on transformations of the start profile and thus maintaining the
identity of vertices and edges.</p>

<blockquote class=""note"">
NOTE&nbsp; Subtypes of the <i>IfcProfileDef</i>
contain parameterized profiles (as subtypes of <i>IfcParameterizedProfileDef</i>)
which establish their own 2D position coordinate system, profiles given
by explicit curve geometry (either open or closed profiles) and two
special types for composite profiles and derived profiles, based on a
2D Cartesian transformation.
</blockquote>

<p>An <i>IfcProfileDef</i>
is treated as bounded area if it is used within swept area solids. In
this case, the inside of the profile is part of the profile. The
attribute <i>ProfileType</i> is set to AREA. An <i>IfcProfileDef</i>
is treated as a curve if it is used within swept surfaces. In this
case, the inside of the profile (if the curve is closed) is not part of
the profile. The attribute <i>ProfileType</i>
is set to CURVE.</p>


<p>Figure 320 illustrates use of parameterized profiles within a swept area solid.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" frame=""border"" width=""100%"">
  <tbody>
    <tr valign=""top"">
      <td align=""left"" valign=""top"" width=""420"">

<img
 src=""figures/IfcProfileDef-Layout1.gif""
 alt=""Example of standard profile definition"" border=""0""
 height=""300"" width=""400"">

      </td>
      <td align=""left"" valign=""top"">

<p><u>Position</u><br>
The <i>IfcProfileDef</i> is defined within the underlying
coordinate system which is defined by the swept surface or swept area solid
that uses the profile definition. It is the xy plane</p>

      <ul>
        <li>of <i>IfcSweptSurface.Position</i> or</li>
        <li>of <i>IfcSweptAreaSolid.Position</i> or</li>
        <li>of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>.</li>
      </ul>

<p>In the figure to the left, the z axis of the position coordinate system points outwards of the drawing plane.</p>

<p><font size=""-1"">Note: The subtype <i>IfcParameterizedProfileDef</i> optionally provides an additional 2D position coordinate system relative to the underlying coordinate system of the <i>IfcProfileDef</i>.</font></p>

      </td>
    </tr>
    <tr>
      <td width=""420"">

<img
 src=""figures/IfcProfileDef-Layout5.gif""
 alt=""use within swept area solids"" border=""0""
 height=""300"" width=""400"">

      </td>
      <td align=""left"" valign=""top"">

<p><u>Sweeping</u></p>

<p>In the later use of the <i>IfcProfileDef</i>
within the swept surface or swept area solid,&nbsp; e.g. the <i>IfcExtrudedAreaSolid</i>
(here used as an example), the profile boundaries (here based on the 2D
position coordinate system of <i>IfcParameterizedProfileDef</i>)
are placed within the xy plane of the 3D position coordinate system of
the swept surface or swept area solid.</p>

<p>The profile is inserted into the underlying coordinate system either:</p>

      <ul>
        <li>directly in case of using <i>IfcArbitraryClosedProfileDef</i>
        and <i>IfcArbitraryOpenProfileDef</i>,</li>

        <li>through an intermediate position coordinate system in case of
        using <i>IfcParameterizedProfileDef</i>.</li>

        <li>through an 2D Cartesian transformation operator (applied directly
        to the curve position when using arbitrary profile definitions,
        or applied to the position coordinate system when using parameterized
        profile definitions) in case of using <i>IfcDerivedProfileDef</i>.</li>

        <li>when using <i>IfcCompositeProfileDef</i> the insertion depends on
        the subtype of the included sub-profiles.</li>
      </ul>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 320 &mdash; Profile sweeping</p></td></tr>
</table>

<p><b>Profile types</b></p>

<p>Results of the different usage of the <i>ProfileType</i> attribute are demonstrated here. The <i>ProfileType</i> defines whether the inside (the bounded area) is part of the profile definition (Area) or not (Curve). Figure 321 illustrates the resulting area or curve depending on <i>ProfileType</i>.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" frame=""border"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420"">

<img src=""figures/IfcProfileDef-Layout3.gif""
 alt=""area without thickness"" height=""225"" width=""300""><br>
ProfileType = AREA

      </td>
      <td align=""left"" valign=""top"">

<img src=""figures/IfcProfileDef-Layout4.gif"" alt=""closed curve""
 height=""225"" width=""300""><br>
ProfileType = CURVE

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 321 &mdash; Profile types</p></td></tr>
</table>


<p><b>Profile specification by external reference</b></p>

<p>If the profile is standardized by a norm or a catalogue, a reference
to this norm or catalogue should be provided by means of <i>HasExternalReference</i>.
This inverse relationship is used to associate an <i>IfcExternalReference</i> (notably
<i>IfcClassificationReference</i> or <i>IfcLibraryReference</i>) with the
profile.</p>

<p><i>IfcClassificationReference</i> is used to refer to a profile norm (a common standard or
manufacturer's standard).  In this case,</p>
<ul>
<li><i>IfcClassificationReference.ItemReference</i>
contains the formal profile designation from the norm.
(On the other hand, <i>IfcProfileDef.ProfileName</i> contains a displayable name which may
not necessarily be the same as the formal designation.)</li>
<li><i>IfcClassificationReference.Name</i> carries the short name of the profile norm.</li>
<li>Optionally, the norm can be further described by
<i>IfcClassificationReference.ReferencedSource</i>.</li>
</ul>

<p><i>IfcLibraryReference</i> is used to refer to a library which contains profile
definitions. In this case,</p>
<ul>
<li><i>IfcLibraryReference.ItemReference</i> contains the identifier of the
profile within the library and is meant to be machine-readable (in contrast to
<i>IfcProfileDef.ProfileName</i> which should be human-readable).</li>
<li><i>IfcLibraryReference.Location</i> and <i>.Name</i> or <i>.ReferencedLibrary</i>
further describe the library.</li>
</ul>

<p>If an external reference is provided, sending systems shall ensure that
the shape of the profile definition object agrees with the definitions in the
referenced classification or library.</p>



<p><b>Direct instances of <i>IfcProfileDef</i></b></p>

<p>Usually, only subtypes of <i>IfcProfileDef</i> should be instantiated.
In some special cases, e.g. if the profile object is used for purposes
other than geometric models (e.g. for structural analysis models), it may be
possible to directly instantiate <i>IfcProfileDef</i> and further specify
the profile only by external reference or by profile properties. The latter
are tracked by the inverse attribute <i>HasProperties</i>.</p>

</EPM-HTML>"
5078;IfcArbitraryOpenProfileDef;"<EPM-HTML>

<p>The open profile <i>IfcArbitraryOpenProfileDef</i> defines an arbitrary two-dimensional open profile for the use within the swept surface geometry. It is given by an open boundary from with the surface can be constructed. </p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x.
</blockquote>

<p><u>Informal proposition</u>:</p>
<ol>
  <li>The <i>Curve</i> has to be an open curve.</li>
</ol>

<p>Figure 308 illustrates the arbitrary open profile definition. The <i>Curve</i> is defined in the underlying coordinate system. The underlying coordinate system is defined by the swept surface that uses the profile definition. It is the xy plane of: </p>
      <ul>
        <li><i>IfcSweptSurface.Position</i></li>
      </ul>
<p>The <i>Curve</i> attribute defines a two dimensional open bounded curve.</p>

<table>
<tr><td><img src=""figures/IfcArbitraryProfileDef-Layout3.gif"" alt=""arbitrary profile without boundaries"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 308 &mdash; Arbitrary open profile</p></td></tr>
</table>

</EPM-HTML>"
5083;IfcCenterLineProfileDef;"<EPM-HTML>

<p>The profile <i>IfcCenterLineProfileDef</i> defines an arbitrary two-dimensional open, not self intersecting profile for the use within the swept solid geometry. It is given by an area defined by applying a constant thickness to a centerline, generating an area from which the solid can be constructed.</p>

<p>Among else, <i>IfcCenterLineProfileDef</i> is used to model cold-formed
steel or aluminium sections (Sigma, Zeta, Omega, and similar sections
which are not covered by subtypes of <i>IfcParameterizedProfileDef</i>).
However, since <i>IfcCenterLineProfileDef</i> does not provide shape parameters
except for the thickness, there is generally a need to further specify the
profile definition by means of</p>
<ul>
  <li>the name,
  <li>external reference to a document or library,</li>
  <li>profile properties,</li>
</ul>
<p>or a combination of them.  See <i>IfcProfileDef</i> for guidance on external references for profiles.</p>

<blockquote class=""change-ifc2x3"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

<p><u>Informal proposition</u>: </p>
<ol>
  <li>The <i>Curve</i> has to be an open curve.</li>
  <li>The <i>Curve</i> has to be a non-intersecting curve.</li>
</ol>

<p>Figure 311 illustrates the center line profile definition. The <i>Curve</i> is defined in the underlying coordinate system. The underlying coordinate system is defined by the swept surface that uses the profile  definition. It is the xy plane of: </p>
      <ul>
        <li><i>IfcSweptSurface.Position</i></li>
      </ul>
<p>The <i>Curve</i> attribute defines a two dimensional open bounded curve. The <i>Thickness</i> attribute defines a constant thickness along the curve.</p>

<table>
<tr><td><img alt=""center line"" src=""figures/IfcArbitraryProfileDef-Layout4.gif"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 311 &mdash; Centerline profile</p></td></tr>
</table>

</EPM-HTML>"
5085;IfcArbitraryClosedProfileDef;"<EPM-HTML>

<p>The closed profile <i>IfcArbitraryClosedProfileDef</i> defines an arbitrary two-dimensional profile for the use within the swept surface geometry, the swept area solid or a sectioned spine. It is given by an outer boundary from which the surface or solid can be constructed. </p>

<blockquote class=""history"">
HISTORY: New entity in IFC 1.5. Entity has been renamed from <i>IfcArbitraryProfileDef</i> in IFC Release 2x.
</blockquote>

<p><u>Informal proposition</u>: </p>
<ol>
  <li>The <i>OuterCurve</i> has to be a closed curve.</li>
  <li>The <i>OuterCurve</i> shall not intersect.</li>
</ol>

<p>Figure 307 illustrates the arbitrary closed profile definition. The <i>OuterCurve</i> is defined in the underlying coordinate system. The underlying coordinate system is defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either:</p>
      <ul>
        <li style=""font-style: italic;"">IfcSweptSurface.Position</li>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
<p>or in case of sectioned spines the xy plane of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>. The <i>OuterCurve</i>
attribute defines a two dimensional closed bounded curve.</p>

<table>
<tr><td><img src=""figures/IfcArbitraryProfileDef-Layout1.gif"" alt=""arbitrary profile without boundaries"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 307 &mdash; Arbitrary closed profile</p></td></tr>
</table>
</EPM-HTML>"
5091;IfcArbitraryProfileDefWithVoids;"<EPM-HTML>

<p>The <i>IfcArbitraryProfileDefWithVoids</i> defines an arbitrary closed two-dimensional profile with holes defined for the use for the swept area solid or a sectioned spine. It is given by an outer boundary and inner boundaries from with the solid the can be constructed.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x.
</blockquote>

<p><u>Informal propositions</u>:</p>
<ol>
  <li>The outer curve and all inner curves shall be closed curves.</li>
  <li>The outer curve shall enclose all inner curves.</li>
  <li>No inner curve shall intersect with the outer curve or any other inner curve.</li>
  <li>No inner curve may enclose another inner curve.</li>
</ol>

<p>Figure 309 illustrates the arbitrary closed profile definition with voids. The <i>OuterCurve</i>, defined at the supertype <i>IfcArbitraryClosedProfileDef</i>
and the inner curves are defined in the same underlying coordinate system. The common underlying coordinate system is defined by the swept area solid that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
      <p>or in case of sectioned spines the xy plane of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>.  The <i>OuterCurve</i> attribute defines a two dimensional closed bounded curve, the <i>InnerCurves</i> define a set of two dimensional closed bounded curves.</p>

<table>
<tr><td align=""left"" valign=""top"" width=""420""><img src=""figures/IfcArbitraryProfileDef-Layout2.gif"" alt=""arbitrary profile with inner boundaries"" border=""0"" height=""300"" 
width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 309 &mdash; Arbitrary profile with voids</p></td></tr>
</table>

</EPM-HTML>"
5096;IfcCompositeProfileDef;"<EPM-HTML>
<p>The <i>IfcCompositeProfileDef</i>
defines the profile by composition of other profiles. The composition
is given by a set of at least two other profile definitions. Any
profile definition (except for another composite profile) can be used
to construct the composite. </p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x.
</blockquote>

<p>Figure 314 illustrates the composite profile definition. The <i>IfcCompositeProfileDef</i> does not define an own position coordinate system, it is directly defined in the underlying coordinate system. The underlying coordinate system is defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either:</p>
      <ul>
        <li><i>IfcSweptSurface.Position</i></li>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>Or in case of sectioned spines it is the xy plane of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>. The <i>IfcCompositeProfileDef</i> is defined using other profile definitions. Those other profile definitions are directly inserted into the underlying coordinate system.</p>
      <ul>
        <li>In case of parameterized profile definitions, the <i>Position</i> attribute of those standard profiles is used to place the profiles relatively to each other.</li>
        <li>In case of arbitrary profile definitions, each Cartesian coordinate is given directly within the underlying coordinate system.</li>
      </ul>

<blockquote class=""note"">
NOTE&nbsp; The black coordinate axes show the underlying coordinate system of the swept surface or swept area solid.
</blockquote>

<table>
<tr><td style=""vertical-align: top; text-align: left; width: 400px;""><img src=""figures/IfcCompositeProfileDef-Layout1.gif"" alt=""composite"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 314</p></td></tr>
</table>

<p class=""use-head"">Twin profiles special case</p>

<p>If twin profiles are modeled by profile composition, the base profile should
only be specified once. It is then included into the composite profile directly
and additionally indirectly via <i>IfcMirroredProfileDef</i>. For example, a
double angle made of two L100x10 with 10mm air gap between them, i.e. a
_|&nbsp;|_ shape, can be modeled as</p>

<blockquote><code>
single_L : IfcLShapeProfileDef := IfcLShapeProfileDef(AREA, 'L100X100X10',<br>
&nbsp;&nbsp;&nbsp;&nbsp;IfcAxis2Placement2D(IfcCartesianPoint(((.100+.010)/2., .0)), ?),<br>
&nbsp;&nbsp;&nbsp;&nbsp;.100, .100, .010, .012, ?, 0., ?, ?);<br>
&nbsp;<br>
double_L : IfcCompositeProfileDef := IfcCompositeProfileDef(AREA, 'double angle',<br>
&nbsp;&nbsp;&nbsp;&nbsp;(single_L, IfcMirroredProfileDef(AREA, ?, single_L, ?)), 'twin profile');
</code></blockquote>

</EPM-HTML>"
5101;IfcDerivedProfileDef;"<EPM-HTML>

<p><i>IfcDerivedProfileDef</i> defines the profile by transformation from the parent profile. The transformation is given by a two dimensional transformation operator. Transformation includes translation, rotation, mirror and scaling. The latter can be uniform or non uniform. The derived profiles may be used to define swept surfaces, swept area solids or sectioned spines.</p>

<p>The transformation effects the position, rotation, mirroring or scale of the profile at the underlying coordinate system, i.e. the coordinate system defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either: </p>

<ul>
  <li><i>IfcSweptSurface.Position</i></li>
  <li><i>IfcSweptAreaSolid.Position</i></li>
</ul>

<p>or in case of sectioned spines the xy plane of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>. The position and potential rotation of the <i>ParentProfile</i> within the underlying coordinate system is taken into consideration before applying the Cartesian transformation operator.</p>

<p>Note, if only mirroring is required, <i>IfcMirroredProfileDef</i> should be used instead.</p>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

<p>Figure 316 illustrates examples of derived profiles.</p>

<table>
<tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"">
  <tbody>
    <tr>
      <td align=""left"" valign=""top"" width=""405"">

<img
 src=""figures/IfcDerivedProfileDef-Layout1.gif"" alt=""uniform""
 border=""0"" height=""300"" width=""400"">

      </td>
      <td align=""left"" valign=""top"">

<p><u>Parameter</u><br>
The <i>IfcDerivedProfileDef</i>
is defined using the <i>IfcCartesianTransformationOperator2D</i>
(CTO), which is applied to the parent profile definition. <br>
</p>

<p><u>Example</u><br>
The example shows an uniform scaling and a transformation
of an <i>IfcRectangleProfileDef</i>
to match the lower-left cardinal point. The attributes of the CTO are:<br>
</p>

      <blockquote><tt>Axis1 = NIL (defaults to 1.,0.)<br>
      Axis2 = NIL (defaults to 0.,1.)<br>
      LocalOrigin = IfcCartesianPoint(&lt;1/2 XDim&gt;,&lt;1/2 YDim&gt;)<br>
      Scale = 2.<br>
      </tt></blockquote>

<font size=""-1"">Note: The <i>ParentProfile</i> has a <i>Position</i>
= <i>IfcCartesianPoint</i>(&lt;1/2 XDim&gt;,&lt;1/2 YDim&gt;) already.</font><br>

      </td>
    </tr>
    <tr>
      <td align=""left"" valign=""top"" width=""405"">

<img
 src=""figures/IfcDerivedProfileDef-Layout2.gif"" alt=""non uniform""
 border=""0"" height=""300"" width=""400"">

      </td>
      <td align=""left"" valign=""top"">

<p><u>Parameter</u><br>
The <i>IfcDerivedProfileDef</i> is defined using
non uniform transformationsby applying the <i>IfcCartesianTransformationOperator2DnonUniform</i>
as a subtype of the 2D CTO.</p>

<p><u>Example</u><br>
The example shows a non-uniform scaling and a translation of an <i>IfcRectangleProfileDef</i>
to match the lower-left cardinal point. The attributes of the CTO are:</p>

      <blockquote><tt>Axis1 = NIL (defaults to 1.,0.)<br>
      Axis2 = NIL (defaults to 0.,1.)<br>
      LocalOrigin = IfcCartesianPoint(0.,&lt;1/2 YDim)<br>
      Scale&nbsp; = 1.<br>
      Scale2 = 2.<br>
      </tt></blockquote>

<font size=""-1"">Note: The <i>ParentProfile</i> has a <i>Position</i>
= <i>IfcCartesianPoint</i>(&lt;1/2 XDim&gt;,&lt;1/2 YDim&gt;) already.</font>

      </td>
    </tr>
    <tr>
      <td align=""left"" valign=""top"">

<img
 alt=""mirroring"" src=""figures/IfcDerivedProfileDef-Layout3.gif""
 border=""0"" height=""300"" width=""400"">

      </td>
      <td align=""left"" valign=""top"">

<p><u>Parameter</u><br>
The <i>IfcDerivedProfileDef</i>
is defined using mirroring by applying the <i>IfcCartesianTransformationOperator2D</i>
(CTO) to the parent profile.</p>

<p><u>Example</u><br>
The example shows a mirroring of an <i>IfcLShapeProfileDef</i>
to match the centre cardinal point. The attributes of the CTO are:</p>

      <blockquote><tt>Axis1 = (-1.,0.)<br>
      Axis2 = NIL (defaults to 0.,1.)<br>
      LocalOrigin = IfcCartesianPoint(0.,0.)<br>
      Scale = NIL (defaults to 1.)<br>
      </tt></blockquote>

<font size=""-1"">Note: The <i>ParentProfile</i> has a <i>Position</i> = <i>IfcCartesianPoint</i>(0.,0.).</font>

<p>This example is for illustration only.
If the transformation results only in mirroring like shown in the example, then
<i>IfcMirroredProfileDef</i> should be used instead of <i>IfcDerivedProfileDef</i>.</p>

      </td>
    </tr>
    <tr>
      <td colspan=""2"" rowspan=""1"" align=""left"" valign=""top"" width=""405"">

<font size=""-1"">Note: The following color map applies:</font><br>

      <ul>
        <li><font size=""-1"">black coordinate axes show the
		underlying coordinate system of the swept surface, swept area solid, or
		sectioned spine</font></li>

        <li><font size=""-1""><font color=""#ff0000"">red coordinate axes</font>
		show the position coordinate system of the parent profile</font></li>

        <li><font size=""-1""><font color=""#993300"">brown coordinate axes</font>
		show the position coordinate system of the derived profile</font></li>
      </ul>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 316 &mdash; Derived profile</p></td></tr>
</table>

</EPM-HTML>"
5107;IfcMirroredProfileDef;"<EPM-HTML> 

<p>The <i>IfcMirroredProfileDef</i> defines the profile by mirroring the parent profile about the y axis of the parent profile coordinate system. That is, left and right of the parent profile are swapped.</p>

<p>Notes:</p>

<p><i>IfcMirroredProfileDef</i> is primarily useful together with
<i>IfcCShapeProfileDef</i>, <i>IfcLShapeProfileDef</i>,
<i>IfcUShapeProfileDef</i>, or <i>IfcZShapeProfileDef</i> as
parent profile but can be used with other parent profile types as well.</p>

<p>Mirroring of an <i>IfcParameterizedProfileDef</i> is performed after
translation and rotation according to its <i>Position</i> attribute.
For example, if the parent profile's <i>Position</i> offsets it by half
of its width to the right, then the mirrored profile will be offset by
half of its width to the left.</p>

<p>Mirroring about the x axis, i.e. swapping top and bottom, can be
achieved by mirroring about the y axis coupled with 180 degree rotation
about the z axis.
In general, rotation happens in a containing object such as
<i>IfcSweptAreaSolid</i>, i.e. after mirroring by <i>IfcMirroredProfileDef</i>
was performed.
If the parent profile is an <i>IfcParameterizedProfileDef</i>, rotation
can alternatively happen already in the parent profile by means of its
<i>Position</i> attribute, i.e. before mirroring by <i>IfcMirroredProfileDef</i>
was performed.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5112;IfcProfileProperties;"<EPM-HTML>

<p>This is a collection of properties applicable to section profile definitions.</p>

<p>The following sets of extended profile property definitions are part of this IFC release:</p>

<ul>
<li><a href=""text/ifcprofileproperties_mechanical.html"" target=""SOURCE"">mechanical properties for all classes of profiles</a></li>
<li><a href=""text/ifcprofileproperties_double_t.html"" target=""SOURCE"">properties for precast concrete double-T sections</a></li>
<li><a href=""text/ifcprofileproperties_hollow_core.html"" target=""SOURCE"">properties for precast concrete hollow core sections</a></li>
</ul>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Entity made non-abstract.  Subtypes <i>IfcGeneralProfileProperties</i>, <i>IfcStructuralProfileProperties</i>, and <i>IfcStructuralSteelProfileProperties</i> deleted. Attribute <i>ProfileName</i> deleted, use <i>ProfileDefinition.ProfileName</i> instead. Attribute <i>ProfileDefinition</i> made mandatory. Attributes <i>Name</i>, <i>Description</i>, and <i>HasProperties</i> added.
</blockquote>

</EPM-HTML>"
5117;IfcIShapeProfileDef;"<EPM-HTML> 

<p><i>IfcIShapeProfileDef</i>
defines a section profile that provides the defining parameters of a
symmetrical 'I' section to be used by the swept surface geometry or the
swept area solid. The I-shape profile has values for its overall depth,
width and its web and flange thickness. Additionally a fillet radius
may be given. It represents a I-section that is symmetrical about its
major and minor axes; and that has both top and bottom flanges being
equal and centred on the web.</p>

<p><i>IfcIShapeProfileDef</i> can also be used to model I sections with
sloped or rounded flanges. The slope and radius cannot be expressed in
explicit attributes, but they may be retrieved by reference to an
external document or library.  See <i>IfcProfileDef</i> for guidance on
external references for profile definitions.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Type of <i>FilletRadius</i> relaxed to allow for zero radius.
</blockquote>

<p>Figure 318 illustrates parameters of the I-shape profile definition.</p>

<table>
<tr><td>
<table border=""1"" cellpadding=""2""
 cellspacing=""2"" frame=""border"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420""><img
 src=""figures/IfcIShapeProfileDef-Layout1.gif""
 alt=""I-shape profile"" border=""0"" height=""300""
 width=""400""></td>
      <td align=""left"" valign=""top""
 width=""100%"">
      <p><u>Position</u>
      <br>
The parameterized
profile defines its own position coordinate system.
The underlying
coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of: </p>
      <ul>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
by using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile. Explicit coordinate offsets are used to define
cardinal points (e.g. upper-left bound).
      <p><u>Parameter</u>
      <br>
The parameterized profile
is defined by a set of parameter attributes, see attribute definition
below.</p>
      </td>
    </tr>
    <tr>
      <td width=""420""><img
 src=""figures/IfcIShapeProfileDef-Layout2.gif""
 alt=""I shape with fillet"" border=""0"" height=""300""
 width=""400""><br>
      <font size=""-1"">Note:
The black coordinate axes show the
underlying coordinate system of the swept surface or swept area solid</font></td>
      <td align=""left"" valign=""top""
 width=""100%"">
      <p><u>Position</u>
      <br>
The profile is inserted into the underlying
coordinate system of the swept area solid by using the <i>Position</i>
attribute. In this example (cardinal point of lower left corner) the
attribute values of <i>IfcAxis2Placement2D</i>
are:</p>
      <blockquote>
        <p> <tt>Location
= IfcCartesianPoint(&lt;1/2
OverallWidth&gt;,&lt;1/2 OverallDepth&gt;)<br>
RefDirection = NIL (defaults to 1.,0.)</tt></p>
      </blockquote>
      <p><u>Parameter</u><br>
If the <i>FilletRadius</i>
is given, it is equally applied to all four corners created by the web
and flanges.</p>
      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 318 &mdash; I-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5127;IfcAsymmetricIShapeProfileDef;"<EPM-HTML>

<p><i>IfcAsymmetricIShapeProfileDef</i>
defines a section profile that provides the defining parameters of a
singly symmetric I-shaped section. Its parameters and orientation relative to the
position coordinate system are according to the following illustration.
The centre of the position coordinate system is in the profile's centre
of the bounding box.</p>

<p>The inherited attributes are redefined as:</p>
  <ul>
    <li><i>OverallWidth -- BottomFlangeWidth</i></li>
    <li><i>FlangeThickness -- BottomFlangeThickness</i></li>
    <li><i>FilletRadius -- BottomFlangeFilletRadius</i></li>
  </ul>
<p>The overall width of the profile is implicitly given by the maximum of
the bottom flange width and the top flange width.</p>

<p><i>IfcAsymmetricIShapeProfileDef</i> can also be used to model rail profiles
if the application scenario does not require a full explicit shape model of the
rail profile. Alternatively, <i>IfcArbitraryClosedProfileDef</i> can be
used to provide the exact shape of rail profiles. Either way, a reference
to an external document or library should be provided to further define the
profile as described at <i>IfcProfileDef</i>.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC2x Edition 2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; All profile origins are now in the center of the bounding box. The attribute <i>CentreOfGravityInY</i> has been made OPTIONAL.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Bottom flange is not necessarily wider than top flange. <i>TopFlangeThickness</i> changed from OPTIONAL to mandatory. Type of <i>TopFlangeFilletRadius</i> relaxed to allow for zero radius. Trailing attribute <i>CentreOfGravityInY</i> deleted, use respective property in <i>IfcExtendedProfileProperties</i> instead.
</blockquote>

<p>Figure 310 illustrates parameters of the asymmetric I-shaped section definition. The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept area solid that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile. The parameterized profile is defined by a set of parameter attributes.  In the illustrated example, the 'CentreOfGravityInY' property in <i>IfcExtendedProfileProperties</i>, if provided, is negative.</p>

<table>
<tr><td><img style=""border: 0px solid ; width: 400px; height: 300px;"" alt=""asymmetric I shape profile"" src=""figures/IfcAsymmetricIShapeProfileDef.gif""></td></tr>
<tr><td><p class=""figure"">Figure 310 &mdash; Assymetric I-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5131;IfcLShapeProfileDef;"<EPM-HTML>

<p><i>IfcLShapeProfileDef</i>
defines a section profile that provides the defining parameters of an
L-shaped section (equilateral L profiles are also covered by this
entity) to be used by the swept area
solid. Its parameters and orientation relative to the position
coordinate system are according to the following illustration. The
shorter leg has the same direction as the positive <i>Position.P[1]</i>-axis, the longer
or equal leg the same as the positive <i>Position.P[2]</i>-axis. The centre of the
position coordinate system is in the profiles centre
of the bounding box.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; All profile origins are now in the center of the bounding box.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; <i>Width</i> changed from OPTIONAL to mandatory.  The previously informal rule that the longer leg is the <i>Depth</i> has been formalized.  Types of <i>FilletRadius</i> and <i>EdgeRadius</i> were relaxed to allow for zero values.  Trailing attributes <i>CentreOfGravityInX</i> and <i>CentreOfGravityInY</i> deleted, use respective properties in <i>IfcExtendedProfileProperties</i> instead.  WHERE rule which required <i>Width</i> &lt;= <i>Depth</i> removed.</blockquote>

<p>Figure 319 illustrates parameters of equal-sided and non-equal sided L-shaped section definitions.</p>

<table>
<tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" width=""100%"">
  <tbody>
    <tr>
      <td align=""left"" valign=""top"" width=""420"">

<img
 alt=""non equal sided L-shape""
 src=""figures/IfcLShapeProfileDef_Layout1.gif"" border=""0""
 height=""300"" width=""400"">

      </td>
      <td align=""left"" valign=""top"">

<p><u>Position</u> <br>
The parameterized profile defines its own position coordinate system.
The underlying coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>by using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile.</p>

<p>In the illustrated example, the 'CentreOfGravityInX' and 'CentreOfGravityInY' properties in <i>IfcExtendedProfileProperties</i>, if provided, are both negative.</p>

      </td>
    </tr>
    <tr>
      <td>

<img
 alt=""equal sided L-shape""
 src=""figures/IfcLShapeProfileDef_Layout2.gif"" border=""0""
 height=""300"" width=""400""><br>

<font size=""-1"">Note:
The black coordinate axes show the
underlying coordinate system of the swept surface or swept area solid</font>

      </td>
      <td align=""left"" valign=""top"">

<p><u>Position</u> <br>
The profile is inserted into the underlying
coordinate system of the swept area solid by using the <i>Position</i>
attribute. In this example (cardinal point of gravity) the
attribute values of <i>IfcAxis2Placement2D</i>
are:</p>

<blockquote>
<p><tt>Location = IfcCartesianPoint(<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;+|CentreOfGravityInX|,<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;+|CentreOfGravityInY|)<br>
RefDirection = NIL (defaults to 1.,0.)</tt></p>
</blockquote>

<p>In the illustrated example, the x and y value of <i>Position.Location</i>, i.e. the <u>measures</u> |CentreOfGravityInX| and |CentreOfGravityInY| are both positive.  On the other hand, the <u>properties</u> named 'CentreOfGravityInX' and 'CentreOfGravityInY' in <i>IfcExtendedProfileProperties</i>, if provided, must both be set to 0 now because the centre of gravity of the resulting profile definition is located in the coordinate origin.</p>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 319 &mdash; L-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5139;IfcUShapeProfileDef;"<EPM-HTML>

<p><i>IfcUShapeProfileDef</i> defines
a section profile that provides the defining parameters of a U-shape
(channel) section to be used by the swept area solid. Its parameters
and orientation relative to the position coordinate system are
according to the following illustration. The centre of the position
coordinate system is in the profile's centre of the bounding box.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; All profile origins are now in the center of the bounding box.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Type of <i>FilletRadius</i> and <i>EdgeRadius</i> relaxed to allow for zero radius.
Trailing attribute <i>CentreOfGravityInX</i> deleted, use respective property in <i>IfcExtendedProfileProperties</i> instead.
</blockquote>

<p>Figure 327 illustrates parameters of the U-shape profile definition.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" width=""100%"">
  <tbody>
    <tr>
      <td valign=""top"" width=""420"">

<img
 src=""figures/IfcUShapeProfileDef.gif"" alt=""U-shape profile""
 border=""0"" height=""300"" width=""400"">

      </td>
      <td valign=""top"">

<p><u>Position</u> <br>
The parameterized profile defines its own position coordinate system.
The underlying coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>By using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile.</p>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 327 &mdash; U-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5149;IfcCShapeProfileDef;"<EPM-HTML>

<p><i>IfcCShapeProfileDef</i> defines
a section profile that provides the defining parameters of a C-shaped
section to be used by the swept area solid. This section is typically
produced by cold forming steel. Its parameters and orientation relative
to the position coordinate system are according to the following
illustration. The centre of the position coordinate system is in the
profile's centre of the bounding box.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; All profile origins are now in the center of the bounding box.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Type of <i>InternalFilletRadius</i> relaxed to allow for zero radius.
Trailing attribute <i>CentreOfGravityInX</i> deleted, use respective property in <i>IfcExtendedProfileProperties</i> instead.
</blockquote>

<p>Figure 315 illustrates parameters of the C-shape profile definition. The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept area solid that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. The parameterized profile is defined by a set of parameter attributes. In the illustrated example, the 'CentreOfGravityInX' property in <i>IfcExtendedProfileProperties</i>, if provided, is negative.</p>

<table>
<tr><td><img src=""figures/IfcCShapeProfileDef.gif"" alt=""C-shape profile"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 315 &mdash; C-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5158;IfcZShapeProfileDef;"<EPM-HTML>

<p><i>IfcZShapeProfileDef</i> defines
a section profile that provides the defining parameters of a Z-shape
section to be used by the swept area solid. Its parameters and
orientation relative to the position coordinate system are according to
the following illustration. The centre of the position coordinate
system is in the profile's centre of the bounding box.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x Edition 4 CHANGE&nbsp; Type of <i>FilletRadius</i> and <i>EdgeRadius</i> relaxed to allow for zero radius.
</blockquote>

<p>Figure 328 illustrates parameters of the Z-shape profile definition.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420"">
<img
 src=""figures/IfcZShapeProfileDef.gif"" alt=""Z-shape profile""
 border=""0"" height=""300"" width=""400"">

      </td>
      <td valign=""top"">

<p><u>Position</u><br>
The parameterized profile defines its own position coordinate system.
The underlying coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
<p>By using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile.</p>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 328 &mdash; Z-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5166;IfcTShapeProfileDef;"<EPM-HTML>

<p><i>IfcTShapeProfileDef</i> defines
a section profile that provides the defining parameters of a T-shaped
section to be used by the swept area solid. Its parameters and
orientation relative to the position coordinate system are according to
the following illustration. The centre of the position coordinate
system is in the profile's centre of the bounding box.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; All profile origins are now in the center of the bounding box.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Type of <i>FilletRadius</i>, <i>FlangeEdgeRadius</i>, and <i>WebEdgeRadius</i> relaxed to allow for zero radius. Trailing attribute <i>CentreOfGravityInY</i> deleted, use respective property in <i>IfcExtendedProfileProperties</i> instead.
</blockquote>

<p>Figure 326 illustrates parameters of the T-shape profile definition.</p>

<table><tr><td>
<table border=""1"" cellpadding=""2"" cellspacing=""2"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420"">
<img
 src=""figures/IfcTShapeProfileDef.gif"" alt=""T-shape profile""
 border=""0"" height=""300"" width=""400"">

      </td>
      <td valign=""top"">

<p><u>Position</u> <br>
The parameterized profile defines its own position coordinate system.
The underlying
coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><small>IfcSweptAreaSolid.Position</small></li>
      </ul>
<p>by using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile.</p>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 326 &mdash; T-shape profile</p></td></tr>
</table>

</EPM-HTML>"
5178;IfcCircleProfileDef;"<EPM-HTML>
<p><i>IfcCircleProfileDef</i> defines a circle as the profile definition used by the swept surface geometry or by the swept area solid. It is given by its <i>Radius</i> attribute and placed within the 2D position coordinate system, established by the <i>Position</i> attribute. </p>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC 1.5.
</blockquote>

<p>Figure 313 illustrates parameters for the circle profile definition. The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either: </p>
      <ul>
        <li><i>IfcSweptSurface.Position</i></li>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>Or in case of sectioned spines, it is the xy plane of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>. By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (e.g. upper-left bound). The <i>Position</i> attribute defines the 2D position coordinate system of the circle.<br> The <i>Radius</i> attribute defines the radius of the circle.</p>

<table>
<tr><td><img src=""figures/IfcCircleProfileDef-Layout1.gif"" alt=""circle profile"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 313 &mdash; Circle profile</p></td></tr>
</table>
</EPM-HTML>"
5181;IfcCircleHollowProfileDef;"<EPM-HTML>
<p><i>IfcCircleHollowProfileDef</i>
defines a section profile that provides the defining parameters of a
circular hollow section (tube) to be used by the swept area solid. Its
parameters and orientation relative to the
position coordinate system are according to the following
illustration.The centre of the position coordinate system is in the
profile's centre of the bounding box (for symmetric profiles identical
with the centre of gravity).</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<p>Figure 312 illustrates parameters of the circular hollow profile definition. The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept area solid that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (for example, upper-left bound). The parameterized profile is defined by a set of parameter attributes.</p>

<table>
<tr><td><img src=""figures/IfcCircleHollowProfileDef.gif"" alt=""CHS-shape profile"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 312 &mdash; Circle hollow profile</p></td></tr>
</table>

</EPM-HTML>"
5184;IfcEllipseProfileDef;"<EPM-HTML>
<p><i>IfcEllipseProfileDef</i> defines an ellipse as the profile definition used by the swept surface geometry
or the swept area solid. It is given by its semi axis attributes and placed within the 2D position coordinate system, established by the <i>Position</i> attribute. </p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x
</blockquote>

<p>Figure 317 illustrates parameters for the ellipse profile definition. The parameterized profile defines its own position coordinate system.
The underlying coordinate system is defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either: </p>
      <ul>
        <li><i>IfcSweptSurface.Position</i></li>
        <li><i>IfcSweptAreaSolid.Position</i></li>
      </ul>
<p>Or in case of sectioned spines it is the xy plane of each list member of <i>IfcSectionedSpine.CrossSectionPositions</i>. By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (for example, upper-left bound). The location of the position coordinate system defines the center of the ellipse. The <i>SemiAxis1</i> attribute defines the first radius of the ellipse in the direction of the X axis, the <i>SemiAxis2</i> attribute defines the second radius of the ellipse in the direction of the Y axis.</p>

<blockquote class=""note"">
NOTE&nbsp; The semi axes of the ellipse are rectangular to each other by definition.
</blockquote>

<table>
<tr><td><img src=""figures/IfcEllipseProfileDef-Layout1.gif"" alt=""ellipse profile"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 317 &mdash; Ellipse profile</p></td></tr>
</table>

</EPM-HTML>"
5187;IfcRectangleProfileDef;"<EPM-HTML>
<p><i>IfcRectangleProfileDef</i> defines a rectangle as the profile definition used by the swept surface geometry or the swept area solid. It is given by its X extent and its Y extent, and placed within the 2D position coordinate system, established by the <i>Position</i> attribute. It is placed centric within the position coordinate system. </p>

<blockquote class=""history"">
HISTORY: New class in IFC 1.5. The use definition has changed in IFC Release 2x.
</blockquote>

<p>Figure 323 illustrates parameters of the rectangle profile definition.</p>

<table><tr><td>
<table frame=""border"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420""><img
 src=""figures/IfcRectangleProfileDef-Layout1.gif""
 alt=""rectangle profile"" border=""0"" height=""300""
 width=""400""></td>
      <td align=""left"" valign=""top""
 width=""100%"">
      <p><u>Position</u>
      <br>
The parameterized profile defines its own position coordinate system.
The underlying
coordinate system is defined by the swept surface or swept area solid
that uses the profile definition. It is the xy plane of either: </p>
      <ul>
        <li style=""font-style: italic;"">IfcSweptSurface.Position</li>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
or in case of sectioned spines the xy plane of each list member of <span
 style=""font-style: italic;"">IfcSectionedSpine.CrossSectionPositions.</span>
      <br>
      <br>
By using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile. Explicit coordinate offsets are used to define
cardinal points (for example, upper-left bound).
      <p><u>Parameter</u>
      <br>
The <i>IfcRectangleProfileDef</i>
is defined within the position
coordinate system, where the <i>XDim</i>
defines the length measure
for the length of the rectangle (half along the positive x-axis) and
the <i>YDim</i>
defines the length measure for the width of the
rectangle (half along the positive y-axis).</p>
      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 323 &mdash; Rectangle profile</p></td></tr>
</table>

</EPM-HTML>"
5192;IfcRectangleHollowProfileDef;"<EPM-HTML>

<p><i>IfcRectangleHollowProfileDef</i> defines a section profile that provides the defining parameters of a rectangular (or square) hollow section to be used by the swept surface geometry or the swept area solid. Its parameters and orientation relative to the position coordinate system are according to the following illustration. A square hollow section can be defined by equal values for h and b. The centre of the position coordinate system is in the profiles centre of the bounding box (for symmetric profiles identical with the centre of gravity). Normally, the longer sides are parallel to the y-axis, the shorter sides parallel to the x-axis.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Types of <i>InnerFilletRadius</i> and <i>OuterFilletRadius</i> relaxed to allow for zero values.
</blockquote>

<p>Figure 322 illustrates parameters of a rectangular or square hollow profile definition.</p>

<table><tr><td>
<table style=""text-align: left; width: 100%;"" border=""1"" cellpadding=""2"" cellspacing=""2"">
  <tbody>
    <tr>
      <td style=""vertical-align: top; text-align: left; width: 420px;"">

<img
 src=""figures/IfcRectangleHollowProfileDef.gif""
 alt=""hollow rectange shape profile"" border=""0""
 height=""300"" width=""400"">

      </td>
      <td style=""vertical-align: top; text-align: left;"">

<p><u>Position</u><br>
The parameterized profile defines its own position coordinate system.
The underlying coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of:</p>
      <ul>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
<p>by using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile.</p>

      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 322 &mdash; Rectangle hollow profile</p></td></tr>
</table>

</EPM-HTML>"
5199;IfcRoundedRectangleProfileDef;"<EPM-HTML>

<p><i>IfcRoundedRectangleProfileDef</i> defines a rectangle with equally rounded corners as the profile definition used by the swept surface geometry or the swept area solid. It is given by the X extent, the Y extent, and the radius for the rounded corners, and placed within the 2D position coordinate system, established by the <i>Position</i> attribute. It is placed centric within the position coordinate system, that is, in the center of the bounding box.
</p>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC2x.
</blockquote>

<blockquote class=""change-ifc2x"">
IFC2x PLATFORM CHANGE&nbsp; The <i>IfcRoundedRectangleProfileDef</i> is now subtyped from <i>IfcRectangleProfileDef</i>. The <i>XDim</i> and <i>YDim</i> attributes have been removed (now inherited from supertype).
</blockquote>

<p>Figure 324 illustrates parameters of the rounded rectangle profile definition.</p>

<table><tr><td>
<table frame=""border"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420""><img
 src=""figures/IfcRoundedRectangleProfileDef-Layout1.gif""
 alt=""rounded rectangle profile"" border=""0"" height=""300""
 width=""400""></td>
      <td align=""left"" valign=""top""
 width=""100%"">
      <p><u>Position</u>
      <br>
The parameterized profile defines its own position coordinate system.
The underlying
coordinate system is defined by the swept surface or swept area solid
that uses the profile definition. It is the xy plane of either: </p>
      <ul>
        <li style=""font-style: italic;"">IfcSweptSurface.Position</li>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
or in case of sectioned spines the xy plane of each list member of <span
 style=""font-style: italic;"">IfcSectionedSpine.CrossSectionPositions.</span>
      <br>
      <br>
By using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile. Explicit coordinate offsets are used to define
cardinal points (e.g. upper-left bound).
      <p><u>Parameter</u>
      <br>
The <i>IfcRoundedRectangleProfileDef</i>
is defined within the
position coordinate system, where the <i>XDim</i>
defines the measure
for the length of the rectangle (half along the positive x-axis), the <i>YDim</i>
defines the length measure for the width of the rectangle (half along
the positive y-axis) and the <i>RoundingRadius</i>
defines the radius
of curvature in all four corners of the rectangle.</p>
      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 324 &mdash; Rounded rectangle profile</p></td></tr>
</table>

</EPM-HTML>"
5202;IfcTrapeziumProfileDef;"<EPM-HTML>

<p><i>IfcTrapeziumProfileDef</i> defines a trapezium as the profile definition used by the swept surface geometry or the swept area solid. It is given by its Top X and Bottom X extent and its Y extent as well as by the offset of the Top X extend, and placed within the 2D position coordinate system, established by the <i>Position</i> attribute. It is placed centric within the position coordinate system, that is, in the center of the bounding box. </p>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC 1.5. The use definition has changed in IFC2x.
</blockquote>

<p>Figure 325 illustrates parameters of the trapezium profile definition.</p>

<table><tr><td>
<table frame=""border"" width=""100%"">
  <tbody>
    <tr>
      <td width=""420""><img
 src=""figures/IfcTrapeziumProfileDef-Layout1.gif""
 alt=""trapezium profile"" border=""0"" height=""300""
 width=""400""></td>
      <td align=""left"" valign=""top""
 width=""100%""><u>Position</u>
      <br>
The parameterized profile defines its own position coordinate system.
The underlying
coordinate system is defined by the swept surface or swept area solid
that uses the profile definition. It is the xy plane of either:
      <ul>
        <li style=""font-style: italic;"">IfcSweptSurface.Position</li>
        <li style=""font-style: italic;"">IfcSweptAreaSolid.Position</li>
      </ul>
or in case of sectioned spines the xy plane of each list member of <span
 style=""font-style: italic;"">IfcSectionedSpine.CrossSectionPositions.</span>
      <br>
      <br>
By using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile. Explicit coordinate offsets are used to define
cardinal points (e.g. upper-left bound).
      <p><u>Parameter</u>
      <br>
The <i>IfcTrapeziumProfileDef</i>
is defined within the position
coordinate system, where the <i>BottomDim</i>
defines the length
measure for the bottom line (half along the positive x-axis) and the <i>YDim</i>
defines the length measure for the parallel distance of bottom and top
line (half along the positive y-axis). The top line starts with a
distance of <i>TopXOffset</i>
from [-BottomLine/2,YDim] (which can be
negative, zero, or positive) and has a length of <i>TopXDim</i>
along
the positive x-axis.</p>
      </td>
    </tr>
  </tbody>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 325 &mdash; Trapezium profile</p></td></tr>
</table>

</EPM-HTML>"
5207;IfcReinforcementBarProperties;"<EPM-HTML>

<p><i>IfcReinforcementProperties</i> defines the set of properties for a specific combination of reinforcement bar steel grade, bar type and effective depth.</p> 

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote> 

<p>The total cross section area for the specific steel grade is always provided. Additionally also general reinforcing bar configurations as a count of bars may be provided as defined in attribute <i>BarCount</i>. In this case the nominal bar diameter should be identical for all given bars as defined in attribute <i>NominalBarDiameter</i>.</p> 

</EPM-HTML>"
5217;IfcSectionProperties;"<EPM-HTML>

<p><i>IfcSectionProperties</i> defines the cross section properties for a single longitudinal piece of a cross section.  It is a special-purpose helper class for <i>IfcSectionReinforcementProperties</i>.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote> 

<p>The section piece may be either uniform or tapered. In the latter case an end profile should also be provided. The start and end profiles are assumed to be of the same profile type. Generally only rectangular or circular cross section profiles are assumed to be used.</p>

</EPM-HTML>"
5224;IfcSectionReinforcementProperties;"<EPM-HTML>

<p><i>IfcSectionReinforcementProperties</i> defines the cross section properties of reinforcement for a single longitudinal piece of a cross section with a specific reinforcement usage type. </p> 

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote> 

<p>Several sets of cross section reinforcement properties represented by instances of <i>IfcReinforcementProperties</i> may be attached to the section reinforcement properties
(<i>IfcReinforcementDefinitionProperties</i> of <i>IfcStructuralElementsDomain</i> schema),
one for each combination of steel grades and reinforcement bar types and sizes.</p>

</EPM-HTML>"
5243;IfcApplication;"<epm-html>

<p><i>IfcApplication</i> holds the information about an IFC compliant application developed by an application developer. The <i>IfcApplication</i> utilizes a short identifying name as provided by the application developer.</p>
	
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC R1.5.
</blockquote>

</epm-html>
"
5253;IfcOwnerHistory;"<epm-html>

<p><i>IfcOwnerHistory</i> defines all history and identification related information. In order to provide fast access it is directly attached to all independent objects, relationships and properties.</p>

<p><i>IfcOwnerHistory</i> is used to identify the creating and owning application and user for the associated object, as well as capture the last modifying application and user.</p>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC R1.0. Modified in IFC R2x4.
</blockquote>

<p><u>Informal propositions</u></p>
<ol>
<li>If LastModifiedDate is defined but ChangeAction is not asserted, then the state of ChangeAction is assumed to be UNDEFINED.</li>	  
<li>If both LastModifiedDate and ChangeAction are asserted, then the state of ChangeAction applies to the value asserted in LastModifiedDate.</li>

</ol>

</epm-html>
"
5275;IfcTable;"<epm-html>

<p>An <i>IfcTable</i> is a data structure for the provision of information in the form of rows and columns. Each instance may have <i>IfcTableColumn</i> instances that define the name, description and units for each column. The rows of information are stored as a list of <i>IfcTableRow</i> objects.</p> 

<p>Limitation: For backwards compatibility, the rows of an <i>IfcTable</i> object are constrained to have the same number of cells. The first Row of the table provides the number of cells. All other rows are forced to include the same number of cells. This is enforced by the WR2.</p> 

<p>Figure 335 illustrates table use.</p>
<table>
<tr><td><img src=""figures/IfcTable_Image1.gif"" width=""426"" height=""192""></td></tr>
<tr><td><p class=""figure"">Figure 335 &mdash; Table use</p></td></tr>
</table>

<p>Figure 336 depicts how tables were structured prior to IFC2x4.</p>
<table>
<tr><td><img src=""figures/IfcTable_Image2.gif"" width=""426"" height=""192""></td></tr>
<tr><td><p class=""figure"">Figure 336 &mdash; Table use alternative</p></td></tr>
</table>

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC R1.5.
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Columns attribute added.
</blockquote>


</epm-html>
"
5284;IfcTableRow;"<epm-html>

<p><i>IfcTableRow</i> contains data for a single row within an <i>IfcTable</i>.</p> 

<p>Limitation: For backward compatibility, all <i>IfcTableRow</i> objects referenced by an <i>IfcTable</i> shall have the same number of Row Cells. The actual number of Cells shall be taken from the number of cells of the first <i>IfcTableRow</i> for that table. The number of Cells is calculated by the derived attribute <i>NumberOfCellsInRow</i> in the associated <i>IfcTable</i>.</p> 

<p>Figure 337 illustrates table row use.</p>
<table>
<tr><td><img src=""figures/IfcTableRow_Image1.gif"" width=""426"" height=""192""></td></tr>
<tr><td><p class=""figure"">Figure 337 &mdash; Table row use</p></td></tr>
</table>

<p>Figure 338 depicts how table rows were structured prior to IFC2x4 with the use of the <i>IsHeading</i> flag. Note that the use of the <i>IfcTableColumn</i> constructs should be used instead of the <i>IsHeading</i> flag (which remains for backward compatibility only):</p> 
<table>
<tr><td><img src=""figures/IfcTableRow_Image2.gif"" width=""426"" height=""192""></td></tr>
<tr><td><p class=""figure"">Figure 338 &mdash; Table row use alternative</p></td></tr>
</table>

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC R1.5.
</blockquote>

</epm-html>
"
5288;IfcTableColumn;"<epm-html>

<p>An <i>IfcTableColumn</i> is a data structure that captures column information for use in an <i>IfcTable</i>. Each instance defines the name, description, identifier, and units of measure that are applicable to the columnar data associated with the <i>IfcTableRow</i> objects.</p> 

<p>The use of <i>IfcTableColumn</i> supercedes the <i>IsHeading</i> flag associated with <i>IfcTableRow</i>.</p> 

<blockquote class=""history""> 
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

</epm-html>
"
5295;IfcBooleanResult;"<EPM-HTML> 
<p><u>Definition from ISO/CD 10303-42:1992</u>: A Boolean result
is the result of a regularized operation on two solids to create
a new solid. Valid operations are regularized union, regularized
intersection, and regularized difference. For purpose of Boolean
operations, a solid is considered to be a regularized set of
points. The final Boolean result depends upon the operation and
the two operands. In the case of the difference operator the
order of the operands is also significant. The operator can be
either union, intersection or difference. The effect of these
operators is described below:</p>
<ul>
<li>Union on two solids is the new solid that is the
regularization of the set of all points that are in either the
first operand or the second operand or in both.</li>
<li>Intersection on two solids is the new solid that is the
regularization of the set of all points that are in both the
first operand and the second operand.</li>
<li>The result of the difference operation on two solids is the
regularization of the set of all points which are in the first
operand, but not in the second operand.</li>
</ul>

<blockquote class=""note"">
NOTE For example if the first operand is a block and the second operand is a solid cylinder of suitable dimensions and location, the boolean result produced with the difference operator would be a block with a circular hole.
</blockquote>
<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: boolean_result. The derived attribute <i>Dim</i> has been added at this level and was therefore demoted from the geometric_representation_item. Please refer to ISO/IS 10303-42:1994, p.175 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY: New class in IFC Release 1.5.1.
</blockquote>

</EPM-HTML>"
5304;IfcHalfSpaceSolid;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A half space solid is defined by the half space which is the regular subset of the domain which lies on one side of an unbounded surface. The side of the surface which is in the half space is determined by the surface normal and the agreement flag. If the agreement flag is TRUE, then the subset is the one the normal points away from. If the agreement flag is FALSE, then the subset is the one the normal points into. For a valid half space solid the surface shall divide the domain into exactly two subsets. Also, within the domain the surface shall be manifold and all surface normals shall point into the same subset. </p> 

<blockquote class=""note""> 
NOTE A half space is not a subtype of solid model (<i>IfcSolidModel</i>), half space solids are only useful as operands in Boolean expressions.
</blockquote> 

<blockquote class=""note""> 
NOTE Corresponding STEP entity: half_space_solid. Please refer to ISO/IS 10303-42:1994, p. 185 for the final definition of the formal standard. The derived attribute <i>Dim</i> has been added at this level and was therefore demoted from the geometric_representation_item.
</blockquote>
<blockquote class=""history"">
HISTORY New class in IFC Release 1.5
</blockquote> 

<p><u>Informal propositions:</u></p> 
<ol> 
<li>The base surface shall divide the domain into exactly two subsets. If the half space solid is of subtype boxed half space (<i>IfcBoxedHalfSpace</i>), the domain in question is that of the attribute enclosure. In all other cases the domain is all of space and the base surface shall be unbounded.</li>  <li>The base surface shall be an unbounded surface (subtype of <i>IfcElementarySurface</i>).</li> 
</ol> 

<p>Figure 258 illustrates the definition of the <i>IfcHalfSpaceSolid</i> within a given coordinate system. The base surface is given by an unbounded plane, the red boundary is shown for visualization purposes only.</p> 

<table cellpadding=""2"" cellspacing=""2""> 
<tr><td><img src=""figures/IfcHalfSpaceSolid-Layout1.gif"" alt=""half space solid"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 258 &mdash; Half space solid geometry</p></td></tr>
</table>
 
</EPM-HTML>"
5310;IfcBoxedHalfSpace;"<EPM-HTML>
<p><u>Definition from ISO/CD 10303-42:1992</u>: This entity is a subtype of the half space solid which is trimmed by a surrounding rectangular box. The box has its edges parallel to the coordinate axes of the geometric coordinate system.</p>

<blockquote class=""note"">
NOTE&nbsp; The purpose of the box is to facilitate CSG computations by producing a solid of finite size.
</blockquote>

<p>The <i>IfcBoxedHalfSpace</i> is
used (as its supertype <i>IfcHalfSpaceSolid</i>) only within
Boolean operations. It divides the domain into exactly two
subsets, where the domain in question is that of the attribute
<i>Enclosure</i>.</p>
<p>The purpose of the attribute <i>Enclosure</i> is to provide a
search box for the other operand in the Boolean operation. It
shall be sufficiently large to fully enclose the resulting solid
after the Boolean operation with the half space. It however does
not alter the final result. The result of the Boolean operation
would be the same, as if executed by the supertype
<i>IfcHalfSpaceSolid</i>. See Figure 253 below.</p>

<table>
<tr><td><img src=""figures/IfcBoxedHalfSpace_01.png"" alt=""correct use of enclosure"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 253 &mdash; Boxed half space operands</p></td></tr>
</table>

<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: boxed_half_space, please refer to ISO/IS 10303-42:1994, p. 185 for the final definition of the formal standard. The IFC class <i>IfcBoundingBox</i> is used for the definition of the enclosure, providing the same definition as box_domain.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.1, improved documentation available in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; Usage correct, position coordinate system for <i>Enclosure</i> is the object coordinate system.
</blockquote>

<p>The <i>IfcBoundingBox</i> (relating to ISO 10303-42:1994 box_domain) that provides the enclosure is given for the convenience of the receiving application to enable the use of size box comparison for efficiency (for example, to check first whether size boxes intersect, if not no calculations has to be done to check whether the solids of the entities intersect).</p>

<p>The <i>Enclosure</i> therefore helps to prevent dealing with infinite-size related issues. The enclosure box is positioned within the object coordinate system</font>, established by the <i>ObjectPlacement</i> of the element represented (for example, by <i>IfcLocalPlacement</i>).  Figure 254 shows the <i>Enclosure</i> box being sufficiently large to fully enclose the Boolean result.</p>

<table frame=""BORDER"">
<tr><td width=""600"" valign=""top"" align=""left""><img src=""figures/IfcBoxedHalfSpace-Layout1.png"" border=""0"" height=""480"" width=""600""></td></tr>
<tr><td><p class=""figure"">Figure 254 &mdash; Boxed half space geometry</p></td></tr>
</table>

</EPM-HTML>

"
5313;IfcBoundingBox;"<EPM-HTML> 
    <p>
      <u>Definition from ISO/CD 10303-42:1992</u>: A box domain
      is an orthogonal box parallel to the axes of the geometric
      coordinate system which may be used to limit the domain of
      a half space solid. A box domain is specified by the
      coordinates of the bottom left corner, and the lengths of
      the sides measured in the directions of the coordinate
      axes.
    </p>
    <p>
      Every semantic object having a
      physical extent might have a minimum default representation
      of a bounding box. The bounding box is therefore also used
      as minimal geometric representation for any geometrically
      represented object. Therefore the <i>IfcBoundingBox</i> is
      subtyped from <i>IfcGeometricRepresentationItem</i>.
    </p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: box_domain, please refer to ISO/IS 10303-42:1994, p. 186 for the final definition of the formal standard. In IFC the bounding box can also be used outside of the context of an <i>IfcBoxedHalfSpace</i>.
</blockquote>
<blockquote class=""history"">
HISTORY New entity in IFC Release 1.0.
</blockquote>

<p>As shown in Figure 252, the <i>IfcBoundingBox</i> is defined with its own location which can be used to place the <i>IfcBoundingBox</i> relative to the geometric coordinate system. The <i>IfcBoundingBox</i> is defined by the lower left corner (<i>Corner</i>) and the upper right corner (<i>XDim, YDim, ZDim</i> measured within the parent co-ordinate system).</p>

<table cellpadding=""2"" cellspacing=""2"">
<tr><td><img src=""figures/IfcBoundingBox-Layout1.gif"" alt=""half space solid"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 252 &mdash; Bounding box</p></td></tr>
</table>

</EPM-HTML>"
5319;IfcPolygonalBoundedHalfSpace;"<EPM-HTML> 
<p>The polygonal bounded
half space is a special subtype of a half space solid, where the
material of the half space used in Boolean expressions is bounded by a
polygonal boundary. <font color=""#0000ff"">The base
surface of the half space is positioned by its normal relativeto the
object coordinate system
(as defined at the supertype <i>IfcHalfSpaceSolid</i>),&nbsp;and
its polygonal (with or without arc segments) boundary is defined in the
XY plane of the position
coordinate system established by the <i>Position</i>
attribute, the subtraction body is extruded perpendicular to the XY
plane of the position coordinate system, that is, into the direction of the
positive Z axis defined by the <i>Position</i> attribute</font>.</p>
<p>The boundary is defined by a 2 dimensional polyline <font
 color=""#0000ff"">(or 2 dimensional composite curve,
consisting of straight segments and circular arc segments)</font>
within the
XY plane of the position coordinate system. The side of the surface
which is in the half space is determined by the surface normal and the
agreement flag. If the agreement flag is TRUE, then the subset is the
one the normal points away from. If the agreement flag is FALSE, then
the subset is the one the normal points into. </p>

<blockquote class=""note"">
NOTE&nbsp; A polygonal bounded half space is not a subtype of <i>IfcSolidModel</i>, half space solids are only useful as operands in Boolean expressions.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 2x.
</blockquote>

<p><u>Informal propositions</u>:</p>
<ol>
  <li>The <i>IfcPolyline</i> <font
 color=""#0000ff"">or the <i>IfcCompositeCurve</i></font>
providing the <i>PolygonalBoundary</i>
shall be closed.</li>
  <li>If the <i>PolygonalBoundary</i>
is given by an <i>IfcCompositeCurve</i>, it shall only
have&nbsp;<font color=""#0000ff""><i><font
 color=""#000000"">I</font><font color=""#000000"">fcCompositeCurveSegment</font></i><font
 color=""#000000"">'s of type <i>IfcPolyline</i>,
or <i>IfcTrimmedCurve</i> (having a <i>BasisCurve</i>
of type <i>IfcLine</i>, or <i>IfcCircle</i>)</font></font></li>
</ol>

<p>Figure 259 illustrates a polygonal bounded half space.</p>
<ul>
<li>Black coordinates indicate the object coordinate system (usually provided by <i>IfcLocalPlacement</i>).</li>
<li>Green coordinates indicate the position coordinate system; the <i>PolygonalBoundary</i> is given within this coordinate system. It is provided by <i>IfcPolygonalBoundedHalfSpace.Position</i>. This coordinate system is relative to the object coordinate system. The extrusion direction of the subtraction body is the positive Z axis.</li>
<li>Red coordinates indicate the normal of the plane. It is provided by the <i>BaseSurface</i> (<i>IfcSurface.Position</i>). This normal is also relative to the object coordinate system.</li>
</ul>

<table border=""0"" cellpadding=""2"" cellspacing=""2"">
<tr><td width=""650""><img alt=""polygonal bounded halfspace"" src=""figures/IfcPolygonalBoundedHalfSpace-Layout1.png"" border=""0"" height=""480"" width=""640""></td></tr>
<tr><td><p class=""figure"">Figure 259 &mdash; Polygonal half space geometry</p></td></tr>
</table>

      <p><u>Purpose</u><br>
The polygonal bounded half space is used to limit the volume of the
half space in Boolean difference expressions. Only the part that is
defined by a theoretical intersection between the half space solid and
an extruded area solid, defined by extruding the polygonal boundary, is
used for Boolean expressions.</p>
      <p><u>Parameter</u><br>
The <i>PolygonalBoundary</i> defines the 2D polyline which
bounds the effectiveness of the half space in Boolean expressions. The <i>BaseSurface</i>
is defined by a plane, and the normal of the plane together with the <i>AgreementFlag</i>
defines the side of the material of the half space.</p>

</EPM-HTML>"
5324;IfcSolidModel;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992:</u> A solid model is a complete representation of the nominal shape of a product such that all points in the interior are connected. Any point can be classified as being inside, outside, or on the boundary of a solid. There are several different types of solid model representations.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303-42 entity: solid_model, only three subtypes have been incorporated into the current IFC Release - subset of manifold_solid_brep (<I>IfcManifoldSolidBrep</I>, constraint to faceted B-rep), swept_area_solid (<I>IfcSweptAreaSolid</I>), the swept_disk_solid (<I>IfcSweptDiskSolid</I>) and subset of csg_solid (<I>IfcCsgSolid</I>). The derived attribute <I>Dim</I> has been added at this level and was therefore demoted from the geometric_representation_item. Please refer to ISO/IS 10303-42:1994, p. 170 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.5
</blockquote>

</EPM-HTML>"
5330;IfcManifoldSolidBrep;"<EPM-HTML> 
<p><u>Definition from ISO/CD 10303-42:1992</u>: A manifold solid
B-rep is a finite, arcwise connected volume bounded by one or
more surfaces, each of which is a connected, oriented, finite,
closed 2-manifold. There is no restriction on the genus of the
volume, nor on the number of voids within the volume.</p>
<p>The Boundary Representation (B-rep) of a manifold solid
utilizes a graph of edges and vertices embedded in a connected,
oriented, finite, closed two manifold surface. The embedded graph
divides the surface into arcwise connected areas known as faces.
The edges and vertices, therefore, form the boundaries of the
face and the domain of a face does not include its boundaries.
The embedded graph may be disconnected and may be a pseudo graph.
The graph is labeled; that is, each entity in the graph has a
unique identity. The geometric surface definition used to specify
the geometry of a face shall be 2-manifold embeddable in the
plane within the domain of the face. In other words, it shall be
connected, oriented, finite, non-self-intersecting, and of
surface genus 0.</p>
<p>Faces do not intersect except along their boundaries. Each
edge along the boundary of a face is shared by at most one other
face in the assemblage. The assemblage of edges in the B-rep do
not intersect except at their boundaries (i.e., vertices). The
geometry curve definition used to specify the geometry of an edge
shall be arcwise connected and shall not self intersect or
overlap within the domain of the edge. The geometry of an edge
shall be consistent with the geometry of the faces of which it
forms a partial bound. The geometry used to define a vertex shall
be consistent with the geometry of the faces and edges of which
it forms a partial bound.</p>
<p>A B-rep is represented by one or more closed shells which
shall be disjoint. One shell, the outer, shall completely enclose
all the other shells and no other shell may enclose a shell. The
facility to define a B-rep with one or more internal voids is
provided by a subtype. The following version of the Euler formula
shall be satisfied, where V, E, F, L<sub>l</sub> and S are the
numbers of unique vertices, edges, faces, loop uses and shells in
the model and G<sup>s</sup> is the sum of the genus of the
shells.</p>
<blockquote>
<blockquote>
<p><img src=""figures/IfcManifoldSolidBrep-Math1.gif"" width=""236""
height=""25""></p>
</blockquote>
</blockquote>

<p>Instances of type <i>IfcManifoldSolidBrep</i> shall be of type
<i>IfcFacetedBrep</i>, using only <i>IfcPolyLoop</i> for the
bounds of <i>IfcFaceBound</i>, or of type <i>IfcAdvancedBrep</i>,
using only <i>IfcAdvancedFace</i> for the face geometry, and
<i>IfcEdgeCurve</i> for the edges.</p>

<blockquote class=""note"">
NOTE: Corresponding ISO 10303-42 entity: manifold_solid_brep. Please refer to ISO/IS 10303-42:1994, p. 170 for the final definition of the formal standard. <i>IfcManifoldSolidBrep</i> is defined as ABSTRACT supertype to prevent it from direct instantiation.
</blockquote>
<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.0
</blockquote>

<p><u>Informal proposition</u>:</p>
<ol>
<li>The dimensionality of a manifold solid brep shall be 3.</li>
<li>The extent of the manifold solid brep shall be finite and
non-zero.</li>
<li>All elements of the manifold solid brep shall have defined
associated geometry.</li>
<li>The shell normals shall agree with the B-rep normal and point
away from the solid represented by the B-rep.</li>
<li>Each face shall be referenced only once by the shells of the
manifold solid brep.</li>
<li>The Euler equation shall be satisfied for the boundary
representation, where the genus term ""shell term"" us the sum of
the genus values for the shells of the brep.</li>
</ol>
</EPM-HTML>"
5334;IfcFacetedBrep;"<EPM-HTML> 
<p><u>Definition from ISO/CD 10303-42:1992</u>: A faceted B-rep
is a simple form of boundary representation model in which all
faces are planar and all edges are straight lines. Unlike the
B-rep model, edges and vertices are not represented explicitly in
the model but are implicitly available through the poly loop
entity. A faceted B-rep has to meet the same topological
constraints as the manifold solid B-rep.</p>

<blockquote class=""note"">
NOTE The faceted B-rep has been introduced in order to support the larger number of systems that allow boundary type solid representations with planar surfaces only.
</blockquote>

<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: faceted_brep. Please refer to ISO/IS 10303-42:1994, p. 173 for the final definition of the formal standard. In the current IFC Release faceted B-rep with voids is represented by an own subtype and not defined via an implicit ANDOR supertype constraint as in ISO/IS 10303-42:1994. This change has been made due to the fact, that only ONEOF supertype constraint is allowed within the IFC data schema.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.0
</blockquote>

<p><u>Informal proposition:</u></p>
<ol>
<li>All the bounding loops of all the faces of all the shells in
the <i>IfcFacetedBrep</i> shall be of type
<i>IfcPolyLoop</i>.</li>
<li>All vertices shall be referenced by all polyloops, sharing the vertex. That is, each Cartesian point shall be referenced by at least three polyloops.</li>
</ol>

<p>Figure 257 illustrates use of <i>IfcFacetedBrep</i> for boundary representation models with planar surfaces only. The diagram shows the topological and geometric representation items that are used for faceted breps. Each <i>IfcCartesianPoint</i>, used within the <i>IfcFacetedBrep</i> shall be referenced three times by an <i>IfcPolyLoop</i> bounding a different <i>IfcFace</i>.</p>

<table summary=""faceted brep"" border=""0"">
<tr><td valign=""top""><img src=""figures/IfcFacetedBrep_01.png"" alt=""faceted brep instantiation"" width=""500"" height=""400""></td></tr>
<tr><td><p class=""figure"">Figure 257 &mdash; Faceted B-rep</p></td></tr> 
</table>

</EPM-HTML>"
5336;IfcFacetedBrepWithVoids;"<EPM-HTML> 
<p>The <i>IfcFacetedBrepWithVoids</i>
is a specialization of a faceted B-rep which contains one or more
voids in its interior. The voids are represented as closed shells
which are defined so that the shell normal point into the
void.</p>

<blockquote class=""note"">
NOTE˙ Corresponding ISO 10303-42 entity: brep_with_voids (see note above). Please refer to ISO/IS 10303-42:1994, p. 173 for the final definition of the formal standard. In IFC faceted B-rep with voids is represented by this subtype <i>IfcFacetedBrepWithVoids</i> and not defined via an implicit ANDOR supertype constraint as in ISO/IS 10303-42:1994 between an instance of faceted_brep AND brep_with_voids. This change has been made due to the fact, that only ONEOF supertype constraint is allowed within the IFC object model.
</blockquote>
<blockquote class=""history"">
HISTORY˙ New entity in IFC Release 1.0
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE˙ Subtyping changed from <i>IfcManifoldSolidBrep</i> to <i>IfcFacetedBrep</i> with upward compatibility for file based exchange.
</blockquote>

<p><u>Informal propositions:</u></p>
<ol>
<li>Each void shell shall be disjoint from the outer shell and
from every other void shell</li>
<li>Each void shell shall be enclosed within the outer shell but
not within any other void shell. In particular the outer shell is
not in the set of void shells</li>
<li>Each shell in the <i>IfcManifoldSolidBrep</i> shall be
referenced only once.</li>
<li>All the bounding loops of all the faces of all the shells in
the <i>IfcFacetedBrep</i> shall be of type
<i>IfcPolyLoop</i>.</li>
</ol>
</EPM-HTML>"
5338;IfcAdvancedBrep;"<EPM-HTML>
<p>An advanced B-rep is a boundary
representation model in which all faces, edges and vertices are
explicitly represented. It is a solid with explicit topology and
elementaty or free-form geometry. The faces of the B-rep are of
type <i>IfcAdvancedFace</i>. An advanced B-rep has to meet the
same topological constraints as the manifold solid B-rep.</p>
<blockquote><small>NOTE The advanced B-rep has been introduced in
order to support the increasing number of applications that can
define and exchange B-rep models based on NURBS or other b-spline
surfaces.</small></blockquote>

<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: advanced_brep_shape_representation. Please refer to ISO/IS 10303-514:1999 for the final definition of the formal standard. There is no explicit entity in ISO 10303-42 for an advanced B-rep, the advanced_brep_shape_representation only ensures that only such kind of manifold B-rep's are used in a shape representation.
</blockquote>
<blockquote class=""history"">
HISTORY New entity in IFC2x4
</blockquote>

<p><u>Informal proposition:</u></p>
<ol>
<li>each face is a face surface;</li>
<li>each face surface has its geometry defined by an elementary
surface, swept surface or a b-spline surface;</li>
<li>the edges used to define the boundaries of the face shall all
reference an edge curve</li>
<li>each curve used to define the geometry of the faces and face
bounds shall be either a conic, or a line or a polyline or a
b-spline curve</li>
<li>the edges used to define the face boundaries shall all be
trimmed by vertices of type vertex point</li>
<li>no loop used to define a face bound shall be of the oriented
subtype</li>
</ol>

<p>Figure 249 illustrates use of <i>IfcAdvancedBrep</i> for boundary representation models with b-spline surfaces. The diagram shows the topological and geometric representation items that are used for advanced B-reps, based on <i>IfcAdvancedFace</i>.</p>

<table summary=""faceted brep"" border=""0"">
<tr><td valign=""top""><img src=""figures/IfcAdvancedBrep_01.png"" alt=""faceted brep instantiation"" width=""600"" height=""600""></td></tr>
<tr><td><p class=""figure"">Figure 249 &mdash; Advanced Brep</p></td></tr>
</table>

</EPM-HTML>"
5341;IfcAdvancedBrepWithVoids;"<EPM-HTML>
<p>The <i>IfcAdvancedBrepWithVoids</i> is a specialization of an
advanced B-rep which contains one or more voids in its interior.
The voids are represented as closed shells which are defined so
that the shell normal point into the void.</p>

<blockquote class=""note"">
NOTE˙ Corresponding ISO 10303-42 entity: brep_with_voids (see note above). Please refer to ISO/IS 10303-42:1994, p. 173 for the final definition of the formal standard. In IFC advanced B-rep with voids is represented by this subtype <i>IfcAdvancedBrepWithVoids</i> and not defined via an implicit ANDOR supertype constraint as in ISO/IS 10303-42:1994 between an instance of manifold_solid_brep AND brep_with_voids. This change has been made due to the fact, that only ONEOF supertype constraint is allowed within the IFC object model.
</blockquote>
<blockquote class=""history"">
HISTORY˙ New entity in IFC2x4
</blockquote>

<p><u>Informal propositions:</u></p>
<ol>
<li>Each void shell shall be disjoint from the outer shell and
from every other void shell</li>
<li>Each void shell shall be enclosed within the outer shell but
not within any other void shell. In particular the outer shell is
not in the set of void shells</li>
<li>Each shell in the <i>IfcManifoldSolidBrep</i> shall be
referenced only once.</li>
<li>All the faces of all the shells in the <i>IfcAdvancedBrep</i>
and the <i>IfcAdvancedBrepWithVoids.Voids</i> shall be of type
<i>IfcAdvancedFace</i>.</li>
</ol>
</EPM-HTML>"
5344;IfcSweptAreaSolid;"<EPM-HTML> 
    <p>
      <u>Definition from ISO/CD 10303-42:1992:</u> The swept area
      solid entity collects the entities which are defined
      procedurally by sweeping action on planar bounded surfaces.
      The position is space of the swept solid will be dependent
      upon the position of the swept area. The swept area will be
      a face of the resulting swept area solid, except for the
      case of a revolved area solid with angle equal to 2&pi;
      (or 360 degrees).
    </p>
    <p>
      The swept area is defined by a
      cross section (also referred to as profile), which is given
      as a closed two-dimensional boundary on an implicit plane.
      The swept area is defined in the xy plane of the position
      coordinate system, which is given for the swept area solid.
    </p>
<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: swept_area_solid, The data type of <i>SweptArea</i> is modified and given by a profile definition (<i>IfcProfileDef</i>). A position coordinate system is defined by the <i>Position</i> attribute has been added. Please refer to ISO/IS 10303-42:1994, p. 183 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY New entity in IFC Release 1.5, the capabilities have been enhanced in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5352;IfcExtrudedAreaSolid;"<EPM-HTML> 
<p>The <em>IfcExtrudedAreaSolid</em> is defined by sweeping a cross
section provided by a profile definition. The direction of the
extrusion is given by the <em>ExtrudedDirection</em> attribute and
the length of the extrusion is given by the <em>Depth</em>
attribute. If the planar area has inner boundaries (holes
defined), then those holes shall be swept into holes of the solid.
The extruded direction can be any direction which is not
perpendicular to the z axis of the position coordinate system of
the profile.</p>
<p>The following definitions from ISO 10303-42 apply:</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">An extruded area
solid is a solid defined by sweeping a bounded planar surface. The
direction of translation is defined by a direction vector, and the
length of the translation is defined by a distance depth. The
planar area may have holes which will sweep into holes in the
solid.</span></p>
</blockquote>
<p>The <em>ExtrudedDirection</em> is given within the position
coordinate system as defined by
<em>IfcSweptAreaSolid.Position</em>. Extrusions are not restricted
to be perpendicular to the extruded surface of the profile.</p>

<p>Figure 255 illustrates geometric parameters of the extruded area solid.  The extruded area solid defines the extrusion of a 2D area (given by a profile definition) by an direction and depth. The result is a
solid. The swept area is given by a profile definition. This profile is defined:</p>
<ul>
<li>as a 2D bounded curve within the xy plane of the position coordinate system,</li>
<li>as a 2D bounded curve with holes within the xy plane of the position coordinate system,</li>
<li>or as a 2D primitive, defined within a 2D position coordinate system, that is placed relative to the xy plane of the position coordinate system</li>
</ul>

<table summary=""geometry"" cellpadding=""2"" cellspacing=""2"" border=""0"">
<tr><td valign=""top"" align=""left""><img src=""figures/IfcExtrudedAreaSolid-Layout1.gif"" alt=""extruded area solid"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 255 &mdash; Extruded area solid geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303-42 entity: extruded_area_solid. Please refer to ISO/IS 10303-42:1994, p. 183 for the final definition of the formal standard. The data type of the inherited <em>SweptArea</em> attribute is different, i.e. of type <em>IfcProfileDef</em>. The <em>Position</em> attribute has been added to position the cross section used for the linear extrusion.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5, capabilities of this entity have been enhanced in IFC Release 2x.</span></p>
</blockquote>

<p class=""use-head"">Texture use definition</p>
<p>For side faces, textures are aligned facing upright continuously
along the sides with origin at the first point of an arbitrary
profile, and following the outer bound of the profile
counter-clockwise (as seen from above). For parameterized profiles,
the origin is defined at the +Y extent for rounded profiles (having
no sharp edge) and the first sharp edge counter-clockwise from the
+Y extent for all other profiles. Textures are stretched or
repeated on each side along the outer boundary of the profile
according to <em>RepeatS</em>. Textures are stretched or repeated
on each side along the extrusion axis according to
<em>RepeatT</em>.</p>
<p>For top and bottom caps, textures are aligned facing
front-to-back, with the origin at the minimum X and Y extent.
Textures are stretched or repeated on the top and bottom to the
extent of each face according to <em>RepeatS</em> and
<em>RepeatT</em>.</p>
<p>For profiles with voids, textures are aligned facing upright
along the inner side with origin at the first point of an arbitrary
profile, and following the inner bound of the profile clockwise (as
seen from above). For parameterized profiles, the origin of inner
sides is defined at the +Y extent for rounded profiles (having no
sharp edge such as hollow ellipses or rounded rectangles) and the
first sharp edge clockwise from the +Y extent for all other
profiles.</p>

<p>Figure 256 illustrates default texture mapping with a repeated texture (RepeatS=True and RepeatT=True). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up. For an <i>IfcExtrudedAreaSolid</i> having a profile of <i>IfcIShapeProfileDef</i>, the side texture coordinate origin is the first corner counter-clockwise from the +Y axis, which equals
(-0.5*IfcIShapeProfileDef.OverallWidth, +0.5*IfcIShapeProfileDef.OverallDepth), while the top (end cap)
texture coordinates start at (-0.5*IfcIShapeProfileDef.OverallWidth,
-0.5*IfcIShapeProfileDef.OverallDepth).</p>

<table summary=""texture"">
<tr><td><img alt=""texture"" src=""figures/IfcExtrudedAreaSolid-Texture.png""></td></tr>
<tr><td><p class=""figure"">Figure 256 &mdash; Extruded area solid textures</t></td></tr>
</table>

</EPM-HTML>"
5357;IfcExtrudedAreaSolidTapered;"<EPM-HTML>
<p><i>IfcExtrudedAreaSolidTapered</i> is defined by sweeping a cross
section along a linear spine. The cross section may change along
the sweep from the shape of the start cross section into the
shape of the end cross section. The resulting solid is bounded by
three or more faces: A start face, an end face (each defined by
start and end planes and sections), and one or more lateral
faces. Each lateral face is a ruled surface defined by a pair of
corresponding edges of the start and end section.</p>
<blockquote><small>NOTE Given that the start and end section is
provided by a polygon, the corresponding vertices of the start
and end cross section are connected, forming a quadrilateral
polygon between each pair of corresponding vertices. The surface
defined by the bounding quadrilateral polygon is a ruled surface,
that could be approximated by triangulation.</small></blockquote>
<p>The linear spine is defined by:</p>
<ul>
<li>Start point:
<i>SELF\IfcSweptAreaSolid.Position.Location</i></li>
<li>Direction:
<i>SELF\IfcExtrudedAreaSolid.ExtrudedDirection</i></li>
<li>Distance: <i>SELF\IfcExtrudedAreaSolid.Depth</i></li>
</ul>
<p>The start cross section is defined by
<i>SELF\IfcSweptAreaSolid.SweptArea</i>:</p>
<ul>
<li>A bounded planar surface lying in the XY plane of the
position coordinate system defined by
<i>SELF\IfcSweptAreaSolid.Position.P[1]</i> and
<i>SELF\IfcSweptAreaSolid.Position.P[2]</i></li>
<li>The linear spine starts at the plane of the start cross
section. The spine is not necessarily perpendicular to the
plane.</li>
</ul>
<p>The end cross section is defined by <i>EndSweptArea</i>:</p>
<ul>
<li>A bounded planar surface lying in the XY plane of the
position coordinate system defined by translating the start
position coordinates provided by
<i>SELF\IfcSweptAreaSolid.Position</i> along the spine direction
by the spine distance. The plane of the end cross section is
coplanar to the plane of the start cross section.</li>
<li style=""list-style: none"">
<ul>
<li>The end cross section is topologically similar to the start
cross section (i.e. having the same number of vertices and
edges).</li>
<li>The end cross section can either be defined by the same
paramteric profile using different parameter values, or by a 2D
Cartesian transformation of the start profile within the end
cross section plane.</li>
</ul>
</li>
</ul>
<p>In case of two parameterized profiles the shape is constructed
as follows:</p>
<ul>
<li>The end profile, defined by a cross section based on the same
profile paramterization as the start profile, is translated by
the spine distance along the spine direction.</li>
<li>It may be shifted within the XY plane of the end postion
coordinate system and may be twisted using the rotation
parameter.</li>
<li>The shift and rotation parameter are provided by the end
cross section being of type <i>IfcParameterizedProfileDef</i>,
where
<ul>
<li>Shift is
<i>EndSweptArea\IfcParameterizedProfileDef.Position.Location</i></li>
<li>Rotation is
<i>EndSweptArea\IfcParameterizedProfileDef.Position.RefDirection</i></li>
</ul>
</li>
<li>Corresponding vertices of the start and end cross section are
connected. Lateral faces are constructed as ruled surfaces
between corresponding edges of start and end cross section.</li>
</ul>
<p>In case of Cartesian transformation of the start cross section
the shape is constructed as follows:</p>
<ul>
<li>The cross section curve, which starts as a curve in the XY
plane of the position coordinate system, is first scaled about
the origin by the scale parameter. It is then translated by the
spine distance along the spine direction. It maybe twisted by
using the rotation parameter.</li>
<li>The scale and rotation parameter are provided by the end
cross section being of type <i>IfcDerivedProfileDef</i>, where
<ul>
<li>Scale is
<i>EndSweptArea\IfcDerivedProfileDef.Operator.Scale</i></li>
<li>Rotation is
<i>EndSweptArea\IfcDerivedProfileDef.Operator.Axis1</i></li>
</ul>
</li>
<li>Corresponding vertices of the start and end cross section are
connected. Lateral faces are constructed as ruled surfaces
between corresponding edges of start and end cross section.</li>
</ul>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p><u>Informal propositions</u></p>
<ol>
<li>Mirroring within <i>IfcDerivedProfileDef.Operator</i> shall
not be used</li>
</ol>

</EPM-HTML>"
5360;IfcRevolvedAreaSolid;"<EPM-HTML> 
<p>An <em>IfcRevolvedAreaSolid</em> is a solid created by revolving
a cross section provided by a profile definition about an axis. The
axis and the cross section shall be in the same plane.</p>
<blockquote><small>NOTE Both the axis and the cross section are
required to lie in the xy plane of the object position coordinate
system.</small></blockquote>
<p>The following definitions from ISO 10303-42 apply:</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">A revolved area solid
is a solid formed by revolving a planar bounded surface about an
axis. The axis shall be in the plane of the surface and the axis
shall not intersect the interior of the bounded surface. The
bounded surface may have holes which will sweep into holes in the
solid. The direction of revolution is clockwise when viewed along
the axis in the positive direction. More precisely if <b>A</b> is
the axis location and <b>d</b> is the axis direction and <b>C</b>
is an arc on the surface of revolution generated by an arbitrary
point <b>p</b> on the boundary of the swept area, then <b>C</b>
leaves <b>p</b> in direction <b>d</b> x (<b>p</b> - <b>A</b>) as
the area is revolved.</span></p>
</blockquote>

<p>Figure 262 illustrates geometric parameters of the revolved solid. The revolved area solid defines the revolution of a 2D area (given by a profile definition) by an axis and angle. The result is a solid. The swept area is given by a profile definition. This profile is defined: </p>
<ul>
<li>as a 2D bounded curve within the xy plane of the position coordinate system,</li>
<li>as a 2D bounded curve with holes within the xy plane of the position coordinate system,</li>
<li>or as a 2D primitive, defined within a 2D position coordinate system, that is placed relative to the xy plane of the position coordinate system</li>
</ul>
<p>The <em>AxisLine</em> can have any orientation within the XY plane, it does not have to be parallel to the y-axis as shown in the illustration.</p>

<table summary=""revolved solid geometry"" cellpadding=""2"" cellspacing=""2"" border=""0"">
<tr><td><img src=""figures/IfcRevolvedAreaSolid-Layout1.gif"" alt=""revolved area solid"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 262 &mdash; Revolved area solid geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303-42 entity: revolved_area_solid. Please refer to ISO/IS 10303-42:1994, p. 184 for the final definition of the formal standard. The data type of the inherited <em>SweptArea</em> attribute is different, i.e. of type <em>IfcProfileDef</em>. The position attribute has been added to position the cross section used for the revolution.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5, capabilities of this entity have been enhanced in IFC Release 2x.
</blockquote>

<p><u>Informal propositions:</u></p>
<ol>
<li>The <em>AxisLine</em> shall lie in the plane of the
<em>SweptArea</em> (as defined at supertype
<em>IfcSweptAreaSolid</em>).</li>
<li>The <em>AxisLine</em> shall not intersect the interior of the
<em>SweptArea</em> (as defined at supertype
<em>IfcSweptAreaSolid</em>).</li>
<li>The <em>Angle</em> shall be between 0&deg; and 360&deg;, or 0
and 2&pi; (depending on the unit type for
<em>IfcPlaneAngleMeasure</em>).</li>
</ol>

<p class=""use-head"">Texture Use Definition</p>
<p>For side faces, textures are aligned facing upright along the
sides with origin at the first point of an arbitrary profile, and
following the outer bound of the profile counter-clockwise (as seen
from above). For parameterized profiles, the origin is defined at
the +Y extent for rounded profiles (having no sharp edge) and the
first sharp edge counter-clockwise from the +Y extent for all other
profiles. Textures are stretched or repeated on each side along the
outer boundary of the profile according to <em>RepeatS</em>.
Textures are stretched or repeated on each side along the outermost
(longest) revolution path according to <em>RepeatT</em>, where
coordinates are compressed towards the axis of revolution.</p>
<p>For top and bottom caps, textures are aligned facing
front-to-back, with the origin at the minimum X and Y extent.
Textures are stretched or repeated on the top and bottom to the
extent of each face according to <em>RepeatS</em> and
<em>RepeatT</em>.</p>
<p>For profiles with voids, textures are aligned facing upright
along the inner side with origin at the first point of an arbitrary
profile, and following the inner bound of the profile clockwise (as
seen from above). For parameterized profiles, the origin of inner
sides is defined at the +Y extent for rounded profiles (having no
sharp edge such as hollow ellipses or rounded rectangles) and the
first sharp edge clockwise from the +Y extent for all other
profiles.</p>

<p>Figure 263 illustrates default texture mapping with a repeated texture (RepeatS=True and RepeatT=True). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up. For an <i>IfcRevolvedAreaSolid</i> having a profile of <i>IfcTShapeProfileDef</i> and revolved at 22.5 degrees, the side texture coordinate origin is the first corner counter-clockwise from the +Y axis, which equals (-0.5*IfcTShapeProfileDef.OverallWidth, +0.5*IfcTShapeProfileDef.OverallDepth), while the top (end cap) texture coordinates start at (-0.5*IfcTShapeProfileDef.OverallWidth, -0.5*IfcTShapeProfileDef.OverallDepth).</p>

<table summary=""texture"">
<tr><td><img alt=""texture"" src=""figures/IfcRevolvedAreaSolid-Texture.png""></td></tr>
<tr><td><p class=""figure"">Figure 263 &mdash; Revolved area solid textures</p></td></tr>
</table>

</EPM-HTML>"
5367;IfcRevolvedAreaSolidTapered;"<EPM-HTML>
<p><i>IfcRevolvedAreaSolidTapered</i> is defined by revolving a
cross section along a circular arc. The cross section may change
along the revolving sweep from the shape of the start cross
section into the shape of the end cross section. Corresponding
vertices of the start and end cross sections are then connected.
The bounded surface may have holes which will sweep into holes in
the solid.</p>
<p>The rotation axis is defined by:</p>
<ul>
<li>Start point:
<i>SELF\IfcSweptAreaSolid.Position.Location</i></li>
<li>Direction: <i>SELF\IfcRevolvedAreaSolid.Axis</i></li>
<li>Rotation axis: <i>SELF\IfcRevolvedAreaSolid.AxisLine</i>,
created from start point and direction by appying a 1 unit
magnitude.</li>
<li>Orientation: Positive angles are applied clockwise when
looking into the positive direction of the rotation axis.</li>
</ul>
<p>The start cross section is defined by
<i>SELF\IfcSweptAreaSolid.SweptArea</i>:</p>
<ul>
<li>A bounded planar surface lying in the XY plane of the
position coordinate system defined by
<i>SELF\IfcSweptAreaSolid.Position.P[1]</i> and
<i>SELF\IfcSweptAreaSolid.Position.P[2]</i></li>
<li>The rotation axis lies in the plane of the start cross
section but shall not intersect the interior of the start cross
section.</li>
</ul>
<p>The end cross section is defined by <i>EndSweptArea</i>:</p>
<ul>
<li>A bounded planar surface lying in the XY plane of the
position coordinate system defined by rotating the start position
coordinates provided by <i>SELF\IfcSweptAreaSolid.Position</i>
around the rotation axis by the angle given by
<i>SELF\IfcRevolvedAreaSolid.Angle</i>.</li>
<li style=""list-style: none"">
<ul>
<li>The end cross section is topologically similar to the start
cross section (having the same number of vertices and edges).</li>
<li>The end cross section can either be defined by the same
paramteric profile using different parameter values, or by a 2D
Cartesian transformation of the start profile within the end
cross section plane.</li>
</ul>
</li>
</ul>
<p>The solid is generated by transforming the start cross section
into to end cross section. A start face, an end face (each
defined by start and end cross sections), and one or more lateral
faces. Each lateral face is a ruled surface defined by a pair of
corresponding edges of the start and end section. The ruled
surfaces are constructed in the cylindrical coordinate space
defined by the supertype <i>IfcRevolvedAreaSolid</i>.""</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p><u>Informal propositions</u></p>
<ol>
<li>Mirroring within <i>IfcDerivedProfileDef.Operator</i> shall
not be used</li>
</ol>

</EPM-HTML>"
5370;IfcSurfaceCurveSweptAreaSolid;"<EPM-HTML>
<p>The <em>IfcSurfaceCurveSweptAreaSolid</em> is the result of
sweeping an area along a directrix that lies on a reference
surface. The swept area is provided by an <em>IfcProfileDef</em>
(or subtypes). The profile definition is based on a 2D coordinate
system, which is inserted into the XY plane of the 3D
<em>Position</em> coordinate system inherited from the supertype
<em>IfcSweptAreaSolid</em>.</p>
<p>The following definitions from ISO 10303-42 apply:</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">A surface curve swept
area solid is a type of swept area solid which is the result of
sweeping a face along a <em>Directrix</em> lying on a
<em>ReferenceSurface</em>. The orientation of the
<em>SweptArea</em> is related to the direction of the surface
normal.</span></p>
<p><span style=""font-size:smaller;color:blue"">The
<em>SweptArea</em> is required to be a curve bounded surface lying
in the plane z = 0 and this is swept along the <em>Directrix</em>
in such a way that the origin of the local coordinate system used
to define the <em>SweptArea</em> is on the <em>Directrix</em> and
the local x-axis is in the direction of the normal to the
<em>ReferenceSurface</em> at the current point. The resulting solid
has the property that the cross section of the surface by the
normal plane to the <em>Directrix</em> at any point is a copy of
the <em>SweptArea</em>.</span></p>
<p><span style=""font-size:smaller;color:blue"">The orientation of
the <em>SweptArea</em> as it sweeps along the <em>Directrix</em> is
precisely defined by a Cartesian Transformation Operator 3D with
attributes:</span></p>
<ul>
<li><span style=""font-size:smaller;color:blue""><em>LocalOrigin</em>
as point (0; 0; 0),</span></li>
<li><span style=""font-size:smaller;color:blue""><em>Axis1</em> as
the normal N to the <em>ReferenceSurface</em> at the point of the
<em>Directrix</em> with parameter u.</span></li>
<li><span style=""font-size:smaller;color:blue""><em>Axis3</em> as
the direction of the tangent vector t at the point of the
<em>Directrix</em> with parameter u.<br>
The remaining attributes are defaulted to define a corresponding
transformation matrix T(u), which varies with the
<em>Directrix</em> parameter u.</span></li>
</ul>
<p><span style=""font-size:smaller;color:blue"">NOTE&nbsp; The
geometric shape of the solid is not dependent upon the curve
parameterization; the volume depends upon the area swept and the
length of the <em>Directrix</em>.</span></p>
</blockquote>
<p>The attributes of the Cartesian Transformation Operator (as
shown above) should apply to the <em>Position</em> coordinate
system, in which the profile is inserted. The <em>Directrix</em>
and the <em>ReferenceSurface</em> are positioned within the 3D
<em>Position</em> coordinate system.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303-42 entity: surface_curve_swept_area_solid. Please refer to ISO 10303-42 ed.2:1999, p. 274 for the definition in the international standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x2.
</blockquote>

<p>Informal propositions:</p>
<ol>
<li>The <em>SweptArea</em> shall lie in the plane z = 0.</li>
<li>The <em>Directrix</em> shall lie on the
<em>ReferenceSurface</em>.</li>
</ol>

</EPM-HTML> 
"
5375;IfcFixedReferenceSweptAreaSolid;"<EPM-HTML>
<p>A fixed reference swept area solid is a type of swept area solid
which is the result of sweeping a surface along a
<em>Directrix</em>. The orientation of the curve during the
sweeping operation is controlled by the <em>FixedReference</em>
direction.</p>
<p>The <em>SweptArea</em> is required to be a curve bounded surface
lying in the plane z = 0 and this is swept along the
<em>Directrix</em> in such a way that the origin of the local
coordinate system used to define the <em>SweptArea</em> is on the
<em>Directrix</em> and the local X axis is in the direction of the
projection of <em>FixedReference</em> onto the normal plane to the
directrix at this point. The resulting solid has the property that
the cross section of the surface by the normal plane to the
<em>Directrix</em> at any point is a copy of the
<em>SweptArea</em>.</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">NOTE The swept face
is given by <em>IfcProfileDef</em> (or subtypes), the profile
definition is given within a 2D coordinate system, which is
inserted into the XY plane of the <em>Position</em> coordinate
system inherited from the supertype
<em>IfcSweptAreaSolid</em>.</span></p>
</blockquote>
<p>The orientation of the <em>SweptArea</em> as it sweeps along the
<em>Directrix</em> is precisely defined by a
<em>CartesianTransformationOperator3d</em> with attributes:</p>
<ul>
<li><em>LocalOrigin</em> as point (0; 0; 0),</li>
<li><em>Axis1</em> as the <em>FixedReference</em>.</li>
<li><em>Axis3</em> as the direction of the tangent vector <b>t</b>
at the point of the <em>Directrix</em> with parameter
<b>u</b>.</li>
</ul>
<p>The remaining attributes are defaulted to define a corresponding
transformation matrix <b>T(u)</b>, which varies with the
<em>Directrix</em> parameter <b>u</b>.</p>
<blockquote>
<p><span style=""font-size:smaller"">NOTE The geometric shape of the
solid is not dependent upon the curve parameterization; the volume
depends upon the area swept and the length of the
<em>Directrix</em>.</span></p>
</blockquote>
<p>The attributes of the Cartesian Transformation Operator (as
shown above) should apply to the <em>Position</em> coordinate
system, in which the profile is inserted. The <em>Directrix</em>
and the <em>FixedReference</em> are positioned within the 3D
<em>Position</em> coordinate system.</p>

<blockquote class=""note"">
NOTE The entity is defined in analogy to the ISO 10303-42 entity: fixed_reference_swept_surface. Please refer to ISO/DIS 10303-42:2003(E) p. 103.
</blockquote>
<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p>Informal propositions:</p>
<ol>
<li>The <em>SweptArea</em> shall lie in the plane z = 0.</li>
<li>The <em>FixedReference</em> shall not be parallel to a tangent
vector to the directrix at any point along this curve.</li>
<li>The <em>Directrix</em> curve shall be tangent continuous.</li>
</ol>

</EPM-HTML>"
5380;IfcCsgSolid;"<EPM-HTML> 
    <p>
      <u>Definition from ISO/CD 10303-42:1992</u>: A solid
      represented as a CSG model is defined by a collection of
      so-called primitive solids, combined using regularized
      Boolean operations. The allowed operations are
      intersection, union, and difference. As a special case a
      CSG solid can also consists of a single CSG primitive.
    </p>
    <p>
      A CSG solid requires two kinds of information for its
      complete definition: geometric and structural.
    </p>
    <ul>
      <li>The geometric information is conveyed by solid models.
      These typically primitive volumes such as cylinders, wedges
      and extrusions, but can include general B-Rep models. Solid
      models can also be half space solids.
      </li>
      <li>The structural information is in a tree (strictly an
      acyclic directed graph) of Boolean result and CSG solids,
      which represent a &#8216;recipe&#8217; for building the
      solid. The terminal nodes are the geometric primitives and
      other solids. Every CSG solid has precisely one Boolean
      result associated with it which is the root of the tree
      that defines the solid. (There may be further Boolean
      results within the tree as operands). The significance of a
      CSG solid entity is that the solid defined by the
      associated tree is thus identified as a significant object
      itself, and in this way it is distinguished from other
      Boolean result entities representing intermediate results
      during the construction process.
      </li>
    </ul>
    <p>
      <u>Definition from IAI</u>: The following primitive volumes
      can be parts of the CSG tree: solid models, i.e. faceted
      B-Rep (<i>IfcFacetedBrep, IfcFacetedBrepWithVoids</i>),
      swept area solid (<i>IfcExtrudedAreaSolid,
      IfcRevolvedAreaSolid, IfcSurfaceCurveSweptAreaSolid</i>),
      swept disk solids (<i>IfcSweptDiskSolid</i>), half space
      solids (<i>IfcHalfSpaceSolid</i> and subtypes), and CSG
      primitives (subtypes of <i>IfcCsgPrimitive3D</i>).
    </p>
<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: csg_solid, please refer to ISO/IS 10303-42:1994, p.174 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY New class in IFC Release 1.5.1
</blockquote>

</EPM-HTML>"
5385;IfcCsgPrimitive3D;"<EPM-HTML>

<p><i>IfcCsgPrimitive3D</i> is an abstract supertype of all three dimensional primitives used as either tree root item, or as Boolean results within a CSG solid model. All 3D CSG primitives are defined within a three-dimensional placement coordinate system.</p>

<blockquote class=""note"">
NOTE˙ No directly corresponding ISO 10303-42 entity, the select type primitive_3d covers the same individual 3D CSG primitives, the position attribute has been added to apply equally to all subtypes. Please refer to ISO/IS 10303-42:1994, p. 234 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x3.
</blockquote>

</EPM-HTML>"
5393;IfcBlock;"<EPM-HTML>
<p>The <em>IfcBlock</em> is a Construction Solid Geometry (CSG) 3D
primitive. It is defined by a position and a positve distance along
the three orthogonal axes. The inherited <em>Position</em>
attribute has the <em>IfcAxisPlacement3D</em> type and
provides:</p>
<ul>
<li><em>SELF\IfcCsgPrimitive3D.Position</em>: The location and
orientation of the axis system for the primitive.</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Location</em>: The block
has one vertex at location and the edges are aligned with the
placement axes in the positive sense.</li>
</ul>
<p>The <em>XLength</em>, <em>YLength</em>, and <em>ZLength</em>
attributes define the size of the IfcBlock along the three
axes.</p>
<p>The following definitions from ISO 10303-42 apply:</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">A block is a solid
rectangular parallelepiped, defined with a location and placement
coordinate system. The block is specified by the positive lengths
x, y, and z along the axes of the placement coordinate system, and
has one vertex at the origin of the placement coordinate
system.</span></p>

<p>Figure 250 illustrates geometric parameters of a block where the block positioned within its own placement coordinate system. The values for <em>XLength</em>, <em>YLength</em>, and <em>ZLength</em> are applied to the positive direction of the X, Y, and Z axis.</p>

<table cellpadding=""2"" cellspacing=""2"" summary=""block geometry"">
<tr><td><img alt=""block"" src=""figures/IfcBlock-Layout1.png"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 250 &mdash; Block geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303-42 entity: block, the position attribute has been promoted to the immediate supertype <em>IfcCsgPrimitive3D</em>. Please refer to ISO 10303-42:1994, p. 244 for the definition in the international standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

<p class=""use-head"">Texture use definition</p>
<p>On each side face, textures are aligned facing upright. On the
top and bottom faces, textures are aligned facing front-to-back.
Textures are stretched or repeated to the extent of each face
according to <em>RepeatS</em> and <em>RepeatT</em>.</p>

<p>Figure 251 illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up.</p>

<table summary=""block texture"" style=""border-width:1px;border-style:solid;border-color:gray"">
<tr><td><img src=""figures/IfcBlock-Texture.png"" alt=""texture""></td></tr>
<tr><td>
<table summary=""texture"" width=""512"" >
<tr>
<td><u>Side</u></td>
<td><u>Normal</u></td>
<td><u>Origin X</u></td>
<td><u>Origin Y</u></td>
<td><u>Origin Z</u></td>
<td><u>S Axis</u></td>
<td><u>T Axis</u></td>
</tr>
<tr>
<td>Left</td>
<td>-X</td>
<td>0</td>
<td>+YLength</td>
<td>0</td>
<td>-Y</td>
<td>+Z</td>
</tr>
<tr>
<td>Right</td>
<td>+X</td>
<td>0</td>
<td>+YLength</td>
<td>0</td>
<td>+Y</td>
<td>+Z</td>
</tr>
<tr>
<td>Front</td>
<td>+X</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>+X</td>
<td>+Z</td>
</tr>
<tr>
<td>Back</td>
<td>+Y</td>
<td>+XLength</td>
<td>+YLength</td>
<td>0</td>
<td>-X</td>
<td>+Z</td>
</tr>
<tr>
<td>Bottom</td>
<td>-Z</td>
<td>+XLength</td>
<td>0</td>
<td>0</td>
<td>-X</td>
<td>+Y</td>
</tr>
<tr>
<td>Top</td>
<td>+Z</td>
<td>0</td>
<td>0</td>
<td>+ZLength</td>
<td>+X</td>
<td>+Y</td>
</tr>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 251 &mdash; Block textures</p></td></tr>
</table>

</EPM-HTML>"
5397;IfcRectangularPyramid;"<EPM-HTML>
<p>The <em>IfcRectangularPyramid</em> is a Construction Solid
Geometry (CSG) 3D primitive. It is a solid with a rectangular base and
a point called apex as the top. The tapers from the base to the
top. The axis from the center of the base to the apex is
perpendicular to the base. The inherited <em>Position</em>
attribute defines the <em>IfcAxisPlacement3D</em> and provides the
location and orientation of the pyramid:</p>
<ul>
<li><em>SELF\IfcCsgPrimitive3D.Position</em>: The location and
orientation of the axis system for the primitive.&nbsp;</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Location</em>: The center
of the circular area being the bottom face of the cone.</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Position[3]:</em> The
z-axis of the inherited placement coordinate system provides the
center axis of the <em>IfcRightCircularCone</em>, and the apex is
at the <em>Height</em> value applied to the positive direction of
the z-axis. The <em>BottomRadius</em> defines the circular base at
the xy-plane of the placement coordinate system.</li>
</ul>

<p>As shown in Figure 260, the pyramid is positioned within its own placement coordinate system. The origin is the center of the bottom rectangle, that lies in the XY plane. The apex lies on the positive z axis at [0, 0, <em>Height</em>].</p>

<table summary=""geometry"" style=""border-width:1px;border-style:solid;border-color:gray"">
<tr><td><img alt=""cone1"" src=""figures/ifcrectangularpyramid-layout1.png"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 260 &mdash; Rectangular pyramid geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: right_circular_cone, the position attribute has been promoted to the immediate supertype <em>IfcCsgPrimitive3D</em>. No semi_angle attribute, and the radius defines the bottom radius, since only a non-truncated cone is in scope. Please refer to ISO/IS 10303-42:1994, p. 176 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3
</blockquote>

<p class=""use-head"">Texture use definition</p>

<p>On each triangular side face, textures are aligned facing upright. 
Textures are stretched or repeated to the extent of the base of each face according to RepeatS. 
Textures are stretched or repeated towards the top point according to Repeat T, 
where the top point has coordinates of (0.5,1.0) if RepeatT is False. </p>

<p>On the bottom face, textures are aligned facing front-to-back.</p>

<p>Figure 261 illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis
points back to the left, and the Z axis points up.</p>

<table summary=""texture"" style=""border-width:1px;border-style:solid;border-color:gray"">
<tr valign=""top""><td><img alt=""texture"" src=""figures/IfcRectangularPyramid-Texture.png""></td></tr>

<tr><td>
<table summary=""texture"" width=""512"">
<tr>
<td><u>Side</u></td>
<td><u>Normal</u></td>
<td><u>Origin X</u></td>
<td><u>Origin Y</u></td>
<td><u>Origin Z</u></td>
<td><u>S Axis</u></td>
<td><u>T Axis</u></td>
</tr>

<tr>
<td>Left</td>
<td>-X</td>
<td>0</td>
<td>+YLength</td>
<td>0</td>
<td>-Y</td>
<td>(towards top point)</td>
</tr>
<tr>
<td>Right</td>
<td>+X</td>
<td>0</td>
<td>+YLength</td>
<td>0</td>
<td>+Y</td>
<td>(towards top point)</td>
</tr>
<tr>
<td>Front</td>
<td>+X</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>+X</td>
<td>(towards top point)</td>
</tr>
<tr>
<td>Back</td>
<td>+Y</td>
<td>+XLength</td>
<td>+YLength</td>
<td>0</td>
<td>-X</td>
<td>(towards top point)</td>
</tr>
<tr>
<td>Bottom</td>
<td>-Z</td>
<td>+XLength</td>
<td>0</td>
<td>0</td>
<td>-X</td>
<td>+Y</td>
</tr>

</table>
</td></tr>
<tr><td><p class=""figure"">Figure 261 &mdash; Right circular cone textures</p></td></tr>
</table>

</EPM-HTML>"
5401;IfcRightCircularCylinder;"<EPM-HTML>
<p>The <em>IfcRightCircularCylinder</em> is a Construction Solid
Geometry (CSG) 3D primitive. It is a solid with a circular base and
top. The cylindrical surface between if formed by points at a fixed
distance from the axis of the cylinder. The inherited
<em>Position</em> attribute defines the <em>IfcAxisPlacement3D</em>
and provides:</p>
<ul>
<li><em>SELF\IfcCsgPrimitive3D.Position</em>: The location and
orientation of the axis system for the primitive.</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Location</em>: The center
of the circular area being the bottom face of the cylinder.</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Position[3]:</em> The z
axis provides the center axis and the height is measured from the
origin along the positive direction of the z axis.</li>
</ul>
<p>The following definitions from ISO 10303-42 apply:</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">A right circular
cylinder is a CSG primitive in the form of a solid cylinder of
finite height. It is defined by an axis point at the centre of one
planar circular face, an axis, a height, and a radius. The faces
are perpendicular to the axis and are circular discs with the
specified radius. The height is the distance from the first
circular face centre in the positive direction of the axis to the
second circular face centre.</span></p>
</blockquote>

<p>Figure 266 illustrates geometric parameters of the cylinder. The cylinder is positioned within its own placement coordiante system. The origin is the center of the bottom circular disk, that lies in the XY plane. The center of the top circular disk is on the positive z axis at [0, 0, <em>Height</em>].</p>

<table summary=""geometry"">
<tr><td><img alt=""cylinder"" src=""figures/IfcRightCircularCylinder-Layout1.png"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 266 &mdash; Right circular cylinder geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: right_circular_cyclinder, the position attribute has been promoted to the immediate supertype <em>IfcCsgPrimitive3D</em>. Please refer to ISO/IS 10303-42:1994, p. 177 for the definition in the international standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

<p class=""use-head"">Texture use definition</p>
<p>On the circular side, textures are aligned facing upright with
origin at the back (+Y direction) revolving counter-clockwise.
Textures are stretched or repeated to the extent of the
circumference according to RepeatS. Textures are stretched or
repeated to the extent of the <em>Height</em> according to
RepeatT.</p>
<p>On the top and bottom faces, textures are aligned facing
front-to-back, with the center of the circle aligned to the center
of the texture.</p>

<p>Figure 267 illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis
points back to the left, and the Z axis points up.</p>

<table summary=""texture"" style=""border-width:1px;border-style:solid;border-color:gray"">
<tr><td><img alt=""texture"" src=""figures/IfcRightCircularCylinder-Texture.png""></td></tr>
<tr><td>
<table summary=""texture"" width=""512"">
<tr>
<td><u>Side</u></td>
<td><u>Normal</u></td>
<td><u>Origin X</u></td>
<td><u>Origin Y</u></td>
<td><u>Origin Z</u></td>
<td><u>S Axis</u></td>
<td><u>T Axis</u></td>
</tr>
<tr>
<td>Side</td>
<td>-Y</td>
<td>0</td>
<td>+Radius</td>
<td>0</td>
<td>-X</td>
<td>+Z</td>
</tr>
<tr>
<td>Bottom</td>
<td>-Z</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>-X</td>
<td>+Y</td>
</tr>
<tr>
<td>Top</td>
<td>+Z</td>
<td>0</td>
<td>0</td>
<td>+Height</td>
<td>+X</td>
<td>+Y</td>
</tr>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 267 &mdash; Right circular cylinder textures</p></td></tr> 
</table>

</EPM-HTML>"
5404;IfcRightCircularCone;"<EPM-HTML>
<p>The <em>IfcRightCircularCone</em> is a Construction Solid
Geometry (CSG) 3D primitive. It is a solid with a circular base and
a point called apex as the top. The tapers from the base to the
top. The axis from the center of the circular base to the apex is
perpendicular to the base. The inherited <em>Position</em>
attribute defines the <em>IfcAxisPlacement3D</em> and provides the
location and orientation of the cone:</p>
<ul>
<li><em>SELF\IfcCsgPrimitive3D.Position</em>: The location and
orientation of the axis system for the primitive.&nbsp;</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Location</em>: The center
of the circular area being the bottom face of the cone.</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Position[3]:</em> The
z-axis of the inherited placement coordinate system provides the
center axis of the <em>IfcRightCircularCone</em>, and the apex is
at the <em>Height</em> value applied to the positive direction of
the z-axis. The <em>BottomRadius</em> defines the circular base at
the xy-plane of the placement coordinate system.</li>
</ul>

<p>Figure 264 illustrates geometric parameters of the cone. The cone is positioned within its own placement coordinate system. The origin is the center of the bottom circular disk, that lies in the XY plane. The apex lies on the positive z axis at [0, 0, <em>Height</em>].</p>

<table summary=""geometry"">
<tr><td><img alt=""cone1"" src=""figures/IfcRightCircularCone-Layout1.png"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 264 &mdash; Right circular cone geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: right_circular_cone, the position attribute has been promoted to the immediate supertype <em>IfcCsgPrimitive3D</em>. No semi_angle attribute, and the radius defines the bottom radius, since only a non-truncated cone is in scope. Please refer to ISO/IS 10303-42:1994, p. 176 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3
</blockquote>

<p class=""use-head"">Texture use definition</p>
<p>On the circular side, textures are aligned facing upright with
origin at the back (+Y direction) revolving counter-clockwise.
Textures are stretched or repeated to the extent of the base
circumference according to RepeatS. Textures are compressed
linearly going upwards towards the top point according to
RepeatT.</p>
<p>On the bottom face, textures are aligned facing front-to-back,
with the center of the circle aligned to the center of the
texture.</p>

<p>Figure 265 illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up.</p>

<table summary=""texture"" style=""border-width:1px;border-style:solid;border-color:gray"">
<tr><td><img alt=""texture"" src=""figures/IfcRightCircularCone-Texture.png""></td></tr>
<tr><td>
<table summary=""texture"" width=""512"">
<tr>
<td><u>Side</u></td>
<td><u>Normal</u></td>
<td><u>Origin X</u></td>
<td><u>Origin Y</u></td>
<td><u>Origin Z</u></td>
<td><u>S Axis</u></td>
<td><u>T Axis</u></td>
</tr>
<tr>
<td>Side</td>
<td>-Y</td>
<td>0</td>
<td>+Radius</td>
<td>0</td>
<td>-X</td>
<td>(towards top point)</td>
</tr>
<tr>
<td>Bottom</td>
<td>-Z</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>-X</td>
<td>+Y</td>
</tr>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 265 &mdash; Right circular cone textures</p></td></tr>
</table>

</EPM-HTML>"
5407;IfcSphere;"<EPM-HTML>
<p>The <em>IfcSphere</em> is a Construction Solid Geometry (CSG) 3D
primitive. It is a solid where all points at the surface have the
same distance from the center point. The inherited
<em>Position</em> attribute defines the <em>IfcAxisPlacement3D</em>
and provides:</p>
<ul>
<li><em>SELF\IfcCsgPrimitive3D.Position</em>: The location and
orientation of the axis system for the primitive.&nbsp;</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Location</em>: The center
of the sphere.</li>
<li><em>SELF\IfcCsgPrimitive3D.Position.Position[3]:</em> The z
axis points at its positve direction towards the north pole, and by
its negative directions towards the south pole.</li>
</ul>
<p>The following definitions from ISO 10303-42 apply:</p>
<blockquote>
<p><span style=""font-size:smaller;color:blue"">A sphere is a CSG
primitive with a spherical shape defined by a centre and a
radius.</span></p>
</blockquote>

<p>Figure 270 illustrates geometric parameters of the sphere. The sphere is positioned within its own placement coordiante system. The origin is the center of the sphere.</p>

<table>
<tr><td><img alt=""sphere"" src=""figures/IfcSphere-Layout1.png"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 270 &mdash; Sphere geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding STEP entity: sphere, the position attribute, including the centre point,&nbsp; has been promoted to the immediate supertype <em>IfcCsgPrimitive3D</em>. Please refer to ISO/IS 10303-42:1994, p. 175 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x3.
</blockquote>

<p class=""use-head"">Texture Use Definition</p>
<p>Textures are aligned facing upright with origin at the back (+Y direction) revolving counter-clockwise. Textures are stretched or repeated to the extent of the circumference at the equator according to RepeatS and RepeatT.</p>

<p>Figure 271 illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up.</p>

<table summary=""texture"" style=""border-width:1px;border-style:solid;border-color:gray"">
<tr><td><img alt=""texture"" src=""figures/IfcSphere-Texture.png""></td></tr>
<tr><td>
<table summary=""texture"" width=""512"">
<tr valign=""top"">
<td><u>Side</u></td>
<td><u>Normal</u></td>
<td><u>Origin X</u></td>
<td><u>Origin Y</u></td>
<td><u>Origin Z</u></td>
<td><u>S Axis</u></td>
<td><u>T Axis</u></td>
</tr>
<tr valign=""top"">
<td>Side</td>
<td>-Y</td>
<td>0</td>
<td>+Radius</td>
<td>0</td>
<td>(-X, then curving counter-clockwise)</td>
<td>(+Y, then curving towards top)</td>
</tr>
</table>
</td></tr>
<tr><td><p class=""figure"">Figure 271 &mdash; Sphere textures</p></td></tr>
</table>

</EPM-HTML>"
5409;IfcSweptDiskSolid;"<EPM-HTML>
<p><u>Definition from ISO 10303-42:2002</u>: A swept
disk solid is the solid produced by sweeping a circular disk
along a three dimensional curve. During the sweeping operation
the normal to the plane of the circular disk is in the direction
of the tangent to the directrix curve and the center of the disk
lies on the directrix. The circular disk may, optionally, have a
central hole, in this case the resulting solid has a through
hole, or, an internal void when the directrix forms a close
curve.</p>
<p>The <i>StartParam</i> and
<i>EndParam</i> parameter are optional, if not provided they
default to the start and end of the <i>Directrix</i>. Only if the
<i>Directrix</i> is given by a bounded or by a closed curve, it
is permissible to omit the values of <i>StartParam</i> and
<i>EndParam</i>.</p>
<p>If the transitions between consecutive segments of the
<i>Directrix</i> are not tangent continuous, the resulting solid
is created by a miter at half angle between the two segments.
Informal proposition restricts the permissible angle between two
non-tangent continuous segments.</p>

<p>Figure 272 illustrates an example.</p>
<ul>
<li><i>Directrix</i> given as <i>IfcCompositeCurve</i> being
tangent continuous between its segments</li>
<li><i>Directrix</i> being a bounded and open curve</li>
<li>No <i>StartParam</i> and <i>EndParam</i> are provided, start
and end default to start and end of the bounded curve of the
<i>Directrix</i></li>
</ul>

<blockquote class=""note"">NOTE&nbsp; Although the example shows a <i>Directrix</i> as a composite curve on a planar reference surface, the definition of <i>IfcSweptDiskSolid</i> is not restricted to be based on planer curves. However view definitions or implementer agreements may provide restrictions.</blockquote>

<table border=""0"" cellpadding=""2"" cellspacing=""2"" summary=""disk solid usage"">
<tr><td><img src=""figures/IfcSweptDiskSolid-Layout1.png"" alt=""disk solid"" width=""450"" height=""315""></td></tr>
<tr><td><p class=""figure"">Figure 272 &mdash; Swept disk solid geometry</p></td></tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303-42 entity: swept_disk_solid. Please refer to ISO/FDIS 10303-42:2002, p. 282 for the definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 2x2.
</blockquote>
<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE&nbsp; The attribute <i>StartParam</i> and <i>EndParam</i> have been made optional.
</blockquote>

<p><u>Informal proposition</u></p>
<ol>
<li>If the <i>Directrix</i> curve definition is not tangent
continuous, the transition between the segments has to be within
an acceptable limit of tangent discontinuity. Very sharp edges
may result in nearly impossible miter. Implementer agreements may
define acceptable limits for tangent discontinuity.</li>
<li>The segments of the <i>Directrix</i> shall be long enough to
apply the <i>Radius</i>. In case of an arc segment forming part
of the <i>Directrix</i> ,its radius shall be greater then the
disk <i>Radius</i></li>
<li>The <i>Directrix</i> shall not be based on an intersecting
curve.</li>
</ol>
</EPM-HTML>"
5419;IfcSweptDiskSolidPolygonal;"<EPM-HTML>
<p>The <i>IfcSweptDiskSolidPolygonal</i> is a <i>IfcSweptDiskSolid</i> where the <i>Directrix</i> is restricted to be provided by an <i>IfcPolyline</i> only. An optional <i>FilletRadius</i> attribute can be asserted, it is then applied as a fillet to all transitions between the segments of the <i>IfcPolyline</i>.</p>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p><u>Informal proposition</u></p>
<ol>
<li>The <i>FilletRadius</i>, if provided, has to be smaller then
or equal to the length of the start and end segment of the
<i>IfcPolyline</i>, and smaller then or equal to one half of the
lenght of the shortest inner segment.</li>
</ol>
</EPM-HTML>"
5423;IfcSectionedSpine;"<EPM-HTML> 
<p><u>Definition from ISO 10303-42:1999</u>: A sectioned
spine is a representation of the shape of a three dimensional
object composed of a spine curve and a number of planar cross
sections. The shape is defined between the first element of cross
sections and the last element of this set.</p>
<blockquote>
<p>NOTE A sectioned spine may be used to represent a surface or a
solid but the interpolation of the shape between the
cross-sections is not defined. For the representation of a solid
all cross-sections are closed curves.</p>
</blockquote>
<p>A sectioned spine
(<i>IfcSectionedSpine</i>) is a representation of the shape of a
three dimensional object composed by a number of planar cross
sections, and a spine curve. The shape is defined between the
first element of cross sections and the last element of the cross
sections. A sectioned spine may be used to represent a surface or
a solid but the interpolation of the shape between the cross
sections is not defined.</p>
<p>For the representation of a solid all cross sections are
areas. For representation of a surface all cross sections are
curves. The cross sections are defined as profiles, whereas the
consecutive profiles may be derived by a transformation of the
start profile or the previous consecutive profile.</p>
<p>The spine curve shall be of type <i>IfcCompositeCurve</i>,
each of its segments (<i>IfcCompositeCurveSegment</i>) shall
correspond to the part between exactly two consecutive
cross-sections.</p>

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 entity: sectioned spine. Please refer to ISO/DIS 10303-42-ed2:1999, p. 282 for the definition of the formal standard. The cross sections are defined in IFC as <i>IfcProfileDef</i>. The position coordinate systems are added.
</blockquote>
<blockquote class=""history"">
HISTORY New entity in IFC Release 2x.
</blockquote>

<p>Figure 268 illustrates an example of an <i>IfcSectionedSpine</i>.</p>
<ul>
<li>The <i>SpineCurve</i> is given by an <i>IfcCompositeCurve</i> with two <i>Segments</i>. The <i>Segments[1]</i> has a <i>ParentCurve</i> of type <i>IfcPolyline</i> and a <i>Transition</i> = CONTSAMEGRADIENT. The <i>Segments[2]</i> has a <i>ParentCurve</i> of type
<i>IfcTrimmedCurve</i> and a <i>Transition</i> = DISCONTINUOUS.</li>
<li>Each <i>CrossSectionPosition</i> lies at a start or end point of the <i>Segments</i>.</li>
<li>Each <i>CrossSections</i> are inserted by the <i>CrossSectionPositions</i>. The first two cross sections are of
type <i>IfcRectangleProfileDef</i>, the third is of type <i>IfcDerivedProfileDef</i>.</li>
</ul>

<table>
<tr><td><img src=""figures/IfcSectionedSpine-Layout1.gif"" alt=""spine 1"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 268 &mdash; Sectioned spine geometry</p></td></tr>
</table>


<p>Figure 269 illustrates the final result of the <i>IfcSectionedSpine</i>. The body (shown transparently) is not fully defined by the
exchange definition.</p>

<table>
<tr><td><img src=""figures/IfcSectionedSpine.jpg"" alt=""render"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 269 &mdash; Sectioned spine result</p></td></tr>
</table>

<p><u>Informal propositions</u></p>
<ol>
<li>none of the cross sections, after being placed by the cross section positions, shall intersect</li>
<li>none of the cross sections, after being placed by the cross section positions, shall lie in the same plane</li>
<li>the local origin of each cross section position shall lie at the beginning or end of a composite curve segment.</li>
</ol>
</EPM-HTML>"
5431;IfcGeometricSet;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: This entity is intended for the transfer of models when a topological structure is not available.</p> 

<p>The <I>IfcGeometricSet</I> is used for the exchange of shape representations consisting of (2D or 3D) points, curves, and/or surfaces, which do not have a topological structure (such as connected face sets or shells) and are not solid models (such as swept solids, CSG or Brep)</p> 

<blockquote class=""note"">
NOTE: Corresponding ISO 10303-42 entity: geometric_set. The derived attribute <I>Dim</I> has been added at this level and was therefore demoted from the geometric_representation_item. Please refer to ISO/IS 10303-42:1994, p. 190 for the final definition of the formal standard.
</blockquote>
 
<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5436;IfcGeometricCurveSet;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A geometric curve set is a collection of two or three dimensional points and curves.</p>

<p>The <I>IfcGeometricCurveSet</I> is used for the exchange of shape representations consisting of (2D or 3D) points and curves only.</p> 

<blockquote>
NOTE: Corresponding ISO 10303-42 entity: geometric_set. Please refer to ISO/IS 10303-42:1994, p. 190 for the final definition of the formal standard.
</blockquote>
 
<blockquote>
HISTORY: New entity in IFC2x2.
</blockquote>

</EPM-HTML>"
5442;IfcFaceBasedSurfaceModel;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A face based surface model is described by a set of connected face sets of dimensionality 2. The connected face sets shall not intersect except at edges and vertices, except that a face in one connected face set may overlap a face in another connected face set, provided the face boundaries are identical. There shall be at least one connected face set. </p> 

<p>A connected face set may exist independently of a surface model.</p>

<blockquote class=""note"">
NOTE Corresponding STEP entity: face_based_surface_model. Please refer to ISO/IS 10303-42:1994, p. 188 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote> 

<p><u>Informal propositions:</u></p>
<ol>
<li>The connected face sets shall not overlap or intersect except at common faces, edges or vertices.</li>
<li>The fbsm faces have dimensionality 2.</li>
</ol>

</EPM-HTML>"
5445;IfcShellBasedSurfaceModel;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A shell based surface model is described by a set of open or closed shells of dimensionality 2. The shells shall not intersect except at edges and vertices. In particular, distinct faces may not intersect. A complete face of one shell may be shared with another shell. Coincident portions of shells shall both reference the same faces, edges and vertices defining the coincident region. There shall be at least one shell.</p> 

<p>A shell may exist independently of a surface model.</p> 

<blockquote class=""note"">
NOTE Corresponding ISO 10303-42 entity: shell_based_surface_model. Please refer to ISO/IS 10303-42:1994, p. 187 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote> 

<p><u>Informal propositions</u></p> 
<ol> 
<li>The dimensionality of the shell based surface model is 2. </li> 
<li>The shells shall not overlap or intersect except at common faces, edges or vertices.</li> 
</ol>

</EPM-HTML>"
5448;IfcBooleanClippingResult;"<EPM-HTML>

<p>A clipping result is defined as a special subtype of the general Boolean result (<i>IfcBooleanResult</i>). It constrains the operands and the operator of the Boolean result.</p> 

<p>A clipping result is the Boolean difference between a solid (restricted to swept area solid) and a half space solid, whereas more than one difference operation can be applied to the Boolean result.</p> 

<blockquote class=""note""> 
NOTE The <I>IfcBooleanClippingResult</I> is defined as a special case of the boolean_result, as defined in ISO 10303-42:1994, p. 175. It has been added to apply further constraints to the CSG representation type.
</blockquote>
<blockquote class=""history"">
HISTORY New entity in IFC Release 2.x.
</blockquote>

</EPM-HTML>"
5468;IfcAxis2Placement2D;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: The location and orientation in two dimensional space of two mutually perpendicular axes. An axis2_placement_2d is defined in terms of a point, (inherited from the placement supertype), and an axis. It can be used to locate and originate an object in two dimensional space and to define a placement coordinate system. The class includes a point which forms the origin of the placement coordinate system. A direction vector is required to complete the definition of the placement coordinate system. The reference direction defines the placement X axis direction, the placement Y axis is derived from this. </p> 

<p>If the <i>RefDirection</i> attribute is not given, the placement defaults to P[1] (x-axis) as [1.,0.] and P[2] (y-axis) as [0.,1.]. </p> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 name: axis2_placement_2d, please refer to ISO/IS 10303-42:1994, p. 28 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.
</blockquote> 

<p>Figure 275 illustrates the definition of the <I>IfcAxis2Placement2D</I> within the two-dimensional coordinate system.</p> 
<table> 
<tr><td><img src=""figures/IfcAxis2Placement2D-Layout1.gif"" alt=""axis2 placement 2D"" width=""400"" height=""300"" border=""0""></td></tr> 
<tr><td><p class=""figure"">Figure 275 &mdash; Axis2 placement 2D</p></td></tr>
</table>

</EPM-HTML>"
5473;IfcPlacement;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A placement entity defines the local environment for the definition of a geometry item. It locates the item to be defined and, in the case of the axis placement subtypes, gives its orientation.</p> 

<p><u>Additional definition from ISO/WD SC4/WG12/N071 Part42.2 geometry_schema</u>: A placement locates a geometric item with respect to the coordinate system of its geometric context.</p> 

<p><i>IfcPlacement</i> is an abstract supertype not to be directly instantiated, whereas the ISO 10303-42 entity placement can be instantiated to define a placement without orientation. The derived attribute <i>Dim</i> has been added, see also note at <i>IfcGeometricRepresentationItem</i>. </p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: placement. Please refer to ISO/IS 10303-42:1994, p. 27 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5479;IfcGeometricRepresentationItem;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-43:1992</u>: An geometric representation item is a representation item that has the additional meaning of having geometric position or orientation or both. This meaning is present by virtue of: </p> 
	 <ul> 
		<li>being a Cartesian point or a direction </li> 
		<li>referencing directly a Cartesian point or direction </li> 
		<li>referencing indirectly a Cartesian point or direction </li> 
	 </ul> 
<p>An indirect reference to a Cartesian point or direction means that a given geometric item references the Cartesian point or direction through one or more intervening geometry or topology items. </p> 

<blockquote class=""example""> 
EXAMPLE: Consider a circle. It gains its geometric position and orientation by virtue of a reference to axis2_placement (<i>IfcAxis2Placement</i>) that is turn references a cartesian_point (<i>IfcCartesianPoint</i>) and several directions (<i>IfcDirection</i>). 
</blockquote>

<blockquote class=""example""> 
EXAMPLE: Consider a manifold brep. A manifold_solid_brep (<i>IfcManifoldSolidBrep</i>) is a geometric_representation_item (<i>IfcGeometricRepresentationItem</i>) that through several layers of topological_representation_item's (<i>IfcTopologicalRepresentationItem</i>) references poly loops (<i>IfcPolyLoop</i>). Through additional intervening entities poly loops reference cartesian_point's (<i>IfcCartesianPoint</i>).
</blockquote> 

<p>The derivation of the dimensionality of the <i>IfcGeometricRepresentationItem</i> is different to ISO 10303; there is a specific derived attribute at each class that defines the dimensionality, whereas ISO 10303 does it for the representation_context and requires all geometric_representation_item's to have the same dimensionality therein. </p> 

<p>The definition of swept area solids as geometric representation items is different to ISO 10303; it is based on a set of predefined profiles (or cross sections), that is, a set of parameterized geometric primitives widely supported in the industry. Those profiles are used to create volumes through extrusion, revolution and cross section based sweep operations.</p>
 
<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: geometric_representation_item. Please refer to ISO/IS 10303-42:1994, p. 22 for the final definition of the formal standard. The following changes have been made: It does not inherit from ISO/IS 10303-43:1994 entity representation_item. The derived attribute Dim is demoted to the appropriate subtypes. The WR1 has not been incorporated. Not all subtypes that are in ISO/IS 10303-42:1994 have been added to the current IFC Release.
</blockquote>

<blockquote class=""history"">		
HISTORY: New entity in IFC Release 1.5
</blockquote>

</EPM-HTML>"
5496;IfcRepresentationItem;"<EPM-HTML> 

<p><u>Definition from ISO/CD
10303-43:1992</u>: A representation item is an element of
product data that participates in one or more representations or
contributes to the definition of another representation item. A
representation item contributes to the definition of another
representation item when it is referenced by that representation
item.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding entity in ISO 10303-43:1994: representation_item. Please refer to ISO/IS 10303-43:1994, for the final definition of the formal standard. The following changes have been made: The attribute 'name' and the WR1 have not been incorporated.
</blockquote>

<p>The <i>IfcRepresentationItem</i> is used within an <i>IfcRepresentation</i> (directly or indirectly through other <i>IfcRepresentationItem</i>'s) to represent an <i>IfcProductRepresentation</i>. Most commonly these <i>IfcRepresentationItem</i>'s are geometric or topological representation items, that can (but not need to) have presentation style infomation assigned.</p>

<blockquote class=""note"">
NOTE&nbsp; The assignment of a style is only applicable
to the subtypes <i>IfcGeometricRepresentationItem</i>, <i>IfcMappedItem</i> and some selected subtypes of <i>IfcTopologicalRepresentationItem</i> (<i>IfcVertexPoint</i>, <i>IfcEdgeCurve</i>, <i>IfcFaceSurface</i>).
</blockquote>

<p>In case that presentation style information is applied, it can be either applied by an <i>IfcStyledItem</i>, or by an assignment to an <i>IfcPresentationLayerWithStyle</i>. If both are present, and both style assignments include the same subtype of <i>IfcPresentationStyle</i>, then the style assigned by <i>IfcStyledItem</i> takes priority.</p>

<p>Figure 281 shows an instance diagram explaining the use of <i>IfcStyledItem</i> and <i>IfcPresentationLayerWithStyle</i> to apply presentation styles.</p>
<blockquote class=""example"">
EXAMPLE&nbsp; The assignment of style information by a styled item and a presentation layer with style. Since the presentation styles are different, <i>IfcCurveStyle</i> and <i>IfcSurfaceStyle</i>, both are applied to the geometric representation item.
</blockquote>

<table summary=""style assignment"">
<tr><td><img src=""figures/IfcRepresentationItem_Style-1.png"" alt=""styles assigned by layer and styled item""></td>
<tr><td><p class=""figure"">Figure 281 &mdash; Representation item style</p></td></tr>
</table>

<p>Figure 282 shows in instance diagram explaining the override of <em>IfcPresentationLayerWithStyle</em> by <em>IfcStyledItem</em> to apply presentation styles.</p>
<blockquote class=""example"">
EXAMPLE&nbsp; The assignment of style information by a styled item and a presentation layer with style. Since the presentation styles for curve style are aprovided by both, the <em>IfcCurveStyle</em> provided by the <em>IfcStyledItem</em> overrides the <em>IfcCurveStyle</em> provided by the <em>IfcPresentationLayerWithStyle</em>
</blockquote>

<table summary=""style assignment"">
<tr><td><img src=""figures/IfcRepresentationItem_Style-2.png"" alt=""styles assigned by layer and styled item""></td></tr>
<tr><td><p class=""figure"">Figure 282 &mdash; Representation item style override</p></td></tr>
</table>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 2x.
</blockquote>
<blockquote class=""change-ifc2x3"">
IFC2x3 CHANGE&nbsp; The inverse attributes <i>StyledByItem</i> and <i>LayerAssignments</i> have been added. Upward compatibility for file based exchange is guaranteed.
</blockquote>

</EPM-HTML>"
5503;IfcMappedItem;"<EPM-HTML> 
<p><u>Definition from ISO/CD 10303-43:1992</u>: A mapped item is the use of an existing representation (the mapping source - mapped representation) as a representation item in a second representation. </p>

<blockquote class=""note"">
NOTE: A mapped item is a subtype of representation item. It enables a representation to be used as a representation item in one or more other representations. The mapped item allows for the definition of a representation using other representations. </font></p>
</blockquote>

<p>The <i>IfcMappedItem</i> is the inserted instance of a source definition (to be compared with a
block / shared cell / macro definition). The instance is inserted by applying a Cartesian transformation operator as the <i>MappingTarget</i>.</p>

<blockquote class=""example"">
EXAMPLE&nbsp; An <i>IfcMappedItem</i> can reuse other mapped items (ako nested blocks), doing so the <i>IfcRepresentationMap</i> is based on an <i>IfcShapeRepresentation</i> including one or more <i>IfcMappedItem</i>'s.
</blockquote>

<blockquote class=""note"">
NOTE &nbsp; Corresponding ISO 10303 entity: mapped_item. Please refer to ISO/IS
10303-43:1994, for the final definition of the formal standard. The definition of mapping_target (<i>MappingTarget</i>) has been restricted to be of the type cartesian_transformation_operator
(<i>IfcCartesianTransformationOperator</i>).
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 2x.
</blockquote>

<p><u>Informal Propositions</u></p>
<ol>
  <li>A mapped item shall not be self-defining by participating in the definition of the representation being mapped.</li>
  <li>The dimensionality of the mapping source and the mapping target has to be the same, if the mapping source is a geometric representation item.</li>
</ol>

</EPM-HTML>"
5506;IfcRepresentationMap;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-43:1992</u>: A representation map is the identification of a representation and a representation item in that representation for the purpose of mapping. The representation item defines the origin of the mapping. The representation map is used as the source of a mapping by a mapped item.</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: representation_map. Please refer to ISO/IS 10303-43:1994, for the final definition of the formal standard. The following changes have been made: The mapping_origin (<i>MappingOrigin</i>) is constrained to be of type axis2_placement (<i>IfcAxis2Placement</i>).</p>
</blockquote>

<p>An <i>IfcRepresentationMap</i> defines the base definition (also referred to as block, cell or macro) called <i>MappedRepresentation</i> within the <i>MappingOrigin</i>. The <i>MappingOrigin</i> defines the coordinate system in which the <i>MappedRepresentation</i> is defined.</p>

<p>The <i>RepresentationMap</i> is used through an <i>IfcMappeditem</i> in one or several <i>IfcShapeRepresentation</i>'s. An Cartesian transformation operator can be applied to transform the <i>MappedRepresentation</i> into the placement coordinate system of the shape representation. The transformation of the representation map is restricted to be a Cartesian transformation mapping (translation, rotation, mirroring and scaling).</p>

<blockquote class=""note"">
NOTE&nbsp; The definition of a mapping which is used to specify a new representation item comprises a representation map and a mapped item entity. Without both entities, the mapping is not fully defined. Two entities are specified to allow the same source representation to be mapped into multiple new representations.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5511;IfcCartesianTransformationOperator;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A Cartesian transformation operator defines a geometric transformation composed of translation, rotation, mirroring and uniform scaling. The list of normalized vectors u defines the columns of an orthogonal matrix T. These vectors are computed, by the base axis function, from the direction attributes axis1, axis2 and, in Cartesian transformation operator 3d, axis3. If <b>|T|= -1</b>, the transformation includes mirroring. The local origin point <b>A</b>, the scale value <b><i>S</i></b> and the matrix <b>T</b> together define a transformation. </p> 

<p>The transformation for a point with position vector P is defined by </p>
	 
	 <blockquote> 
		<blockquote> 
		  <p>P -&gt; A + <i>S</i>TP </p></blockquote></blockquote> 
	 <p> The transformation for a direction d is defined by </p> 
	 <blockquote> 
		<blockquote> 
		  <p>d -&gt; Td </p></blockquote></blockquote> 
	 <p> The transformation for a vector with orientation d and magnitude k is
		defined by</p> 
	 <blockquote> 
		<blockquote> 
		  <p> d -&gt; Td, and </p> 
		  <p> <i>k -&gt; Sk</i> </p></blockquote></blockquote> 
	 <p>For those entities whose attributes include an axis2 placement, the
		transformation is applied, after the derivation, to the derived attributes p
		defining the placement coordinate directions. For a transformed surface, the
		direction of the surface normal at any point is obtained by transforming the
		normal, at the corresponding point, to the original surface. For geometric
		entities with attributes (such as the radius of a circle) which have the
		dimensionality of length, the values will be multiplied by <i>S</i>. </p> 
	 <p>For curves on surface the p curve.reference to curve will be unaffected
		by any transformation. The Cartesian transformation operator shall only be
		applied to geometry defined in a consistent system of units with the same units
		on each axis. With all optional attributes omitted, the transformation defaults
		to the identity transformation. The Cartesian transformation operator shall
		only be instantiated as one of its subtypes. </p> 

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 entity: cartesian_transformation_operator, please refer to ISO/IS 10303-42:1994, p. 32 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5521;IfcCartesianTransformationOperator2D;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A Cartesian transformation operator 2d defines a geometric transformation in two-dimensional space composed of translation, rotation, mirroring and uniform scaling. The list of normalized vectors u defines the columns of an orthogonal matrix <b>T</b>. These vectors are computed from the direction attributes axis1 and axis2 by the base axis function. If <b>|T|= -1</b>, the transformation includes mirroring. </p> 

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 entity : cartesian_transformation_operator_2d, please refer to ISO/IS 10303-42:1994, p. 36 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5527;IfcCartesianTransformationOperator2DnonUniform;"<EPM-HTML>

<p>A Cartesian transformation operator 2d non uniform defines a geometric transformation in two-dimensional space composed of translation, rotation, mirroring and non uniform scaling. Non uniform scaling is given by two different scaling factors:</p> 
<ul> 
<li><i>SELF\IfcCartesianTransformationOperator.Scale</i>: the x axis scale factor</li> 
<li><i>Scale2</i>: the y axis scale factor</li> 
</ul> 
<p>If the <i>Scale</i> factor (at supertype <i>IfcCartesianTransformationOperator</i>) is omitted, it defaults to 1.0. If the <i>Scale2</i> factor is omitted, it defaults to the value of <i>Scale</i> (the x axis scale factor).</p> 

<blockquote class=""note""> 
NOTE: The scale factor (<i>Scl</i>) defined at the supertype <i>IfcCartesianTransformationOperator</i> is used to express the calculated <i>Scale</i> factor (normally x axis scale factor).
</blockquote> 

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5531;IfcDirection;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: This entity defines a general direction vector in two or three dimensional space. The actual magnitudes of the components have no effect upon the direction being defined, only the ratios X:Y:Z or X:Y are significant. </p> 

<blockquote class=""note"">
NOTE: The components of this entity are not normalized. If a unit vector is required it should be normalized before use.
</blockquote> 

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 entity: direction. Please refer to ISO/IS 10303-42:1994, p.26 for the final definition of the formal standard. The derived attribute <I>Dim</I> has been added (see also note at <I>IfcGeometricRepresentationItem</I>).
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5534;IfcCartesianTransformationOperator3D;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A Cartesian transformation operator 3d defines a geometric transformation in three-dimensional space composed of translation, rotation, mirroring and uniform scaling. The list of normalized vectors u defines the columns of an orthogonal matrix <b>T</b>. These vectors are computed from the direction attributes axis1, axis2 and axis3 by the base axis function. If |<b>T</b>|= -1, the transformation includes mirroring. </p> 

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 entity: cartesian_transformation_operator_3d, please refer to ISO/IS 10303-42:1994, p. 33 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5542;IfcCartesianTransformationOperator3DnonUniform;"<EPM-HTML>

<p>A Cartesian transformation operator 3d non uniform defines a geometric transformation in three-dimensional space composed of translation, rotation, mirroring and non uniform scaling. Non uniform scaling is given by three different scaling factors:</p>

<ul>
<li><i>SELF\IfcCartesianTransformationOperator.Scale</i>: the x axis scale factor</li>
<li><i>Scale2</i>: the y axis scale factor</li>
<li><i>Scale3</i>: the z axis scale factor</li>
</ul>

<p>If the <i>Scale</i> factor (at supertype <i>IfcCartesianTransformationOperator</i>) is omitted, it defaults to 1.0. If the <i>Scale2</i> or the <i>Scale3</i> factor is omitted, it defaults to the value of <i>Scale</i> (the x axis scale factor).</p> 

<blockquote class=""note""> 
NOTE: The scale factor (<i>Scl</i>) defined at the supertype <i>IfcCartesianTransformationOperator</i> is used to express the calculated <i>Scale</i> factor (normally x axis scale factor).
</blockquote>

<blockquote class=""history""> 
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5549;IfcCartesianPoint;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A point defined by its coordinates in a two or three dimensional rectangular Cartesian coordinate system, or in a two dimensional parameter space. The entity is defined in a two or three dimensional space. </p> 

<p>The derived attribute <i>Dim</i> has been added (see also note at <i>IfcGeometricRepresentationItem</i>). The WR1 was added to constrain the usage of <i>IfcCartesianPoint</i> in the context of IFC geometry. For the purpose of defining geometry in IFC only two and three dimensional Cartesian points are used. </P> 

<blockquote class=""note"">
NOTE: Corresponding STEP entity: cartesian_point, please refer to ISO/IS 10303-42:1994, p. 23 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5553;IfcPoint;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A point is a location in some real Cartesian coordinate space R<SUP>m</SUP>, for m = 1, 2 or 3. </p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: point. Only the subtypes cartesian_point, point_on_curve, point_on_surface have been incorporated in the current release of IFC. Please refer to ISO/IS 10303-42:1994, p. 22 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.5
</blockquote>

</EPM-HTML>"
5557;IfcPointOnCurve;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A point on curve is a point which lies on a curve. The point is determined by evaluating the curve at a specific parameter value. The coordinate space dimensionality of the point is that of the basis curve.</p> 

<blockquote class=""note""> 
NOTE: Corresponding STEP entity: point_on_curve. Please refer to ISO/IS 10303-42:1994, p. 23 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in Release IFC2x Edition 2.
</blockquote>

<P><U>Informal Propositions</U>:</P> 
<ol>
<li>The value of the point parameter shall not be outside the parametric range of the curve.</li>
</ol>

</EPM-HTML>"
5561;IfcCurve;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A curve can be envisioned as the path of a point moving in its coordinate space. </p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: curve, only the following subtypes have been incorporated into IFC: line as <i>IfcLine</i>, conic as <i>IfcConic</i>, bounded_curve as <i>IfcBoundedCurve</i>. Please refer to ISO/IS 10303-42:1994, p.37 for the final definition of the formal standard. The derived attribute <i>Dim</i> has been added (see also note at <i>IfcGeometricRepresentationItem</i>).
</blockquote>

<blockquote class=""history""> 
HISTORY: New entity in IFC Release 1.0
</blockquote>
	 
<p><u>Informal proposition:</u></p> 
<ol> 
<li>A curve shall be arcwise connected</li> 
<li>A curve shall have an arc length greater than zero.</li> 
</ol>

</EPM-HTML>"
5569;IfcBoundedCurve;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A bounded curve is a curve of finite arc length with identifiable end points.</p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 name: bounded_curve, only the following subtypes have been incorporated into IFC: polyline as <i>IfcPolyline</i>, trimmed_curve as <i>IfcTrimmedCurve</i>, composite_curve as <i>IfcCompositeCurve</i>. Please refer to ISO/IS 10303-42:1994, p.44 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.0
</blockquote>

<p><u>Informal propositions</u>:</p> 
<ol> 
<li>A bounded curve has finite arc length.</li> 
<li>A bounded curve has a start point and an end point. </li> 
</ol> 

</EPM-HTML>"
5574;IfcCompositeCurve;"<EPM-HTML> 
    <p>
      <u>Definition from ISO/CD 10303-42:1992</u>: A composite
      curve is a collection of curves joined end-to-end. The
      individual segments of the curve are themselves defined as
      composite curve segments. The parameterization of the
      composite curve is an accumulation of the parametric ranges
      of the referenced bounded curves. The first segment is
      parameterized from <i>0</i> to
      <i>l<sub><small>1</small></sub></i> and for <i>i</i>
      <i>&le;</i> <i>2</i>, the
      <i>i<sup><small>th</small></sup></i> segment is
      parameterized from:
    </p>
    <blockquote>
      <p>
        <img src=""figures/IfcCompositeCurve-Math1.gif"" width=
        ""140"" height=""60"">
      </p>
    </blockquote>
    <p>
      where <i>l<sub><small>k</small></sub></i> is the parametric
      length (i.e., difference between maximum and minimum
      parameter values) of the curve underlying the
      <i>k<sup><small>th</small></sup></i> segment.
    </p>
    <p>
      Let <i>T</i> denote the parameter for the composite curve.
      Then, if the <i>i</i>th segment is not a reparameterised
      composite curve segment, <i>T</i> is related to the
      parameter <i>t<sub>i</sub></i>; <i>t<sub>i0</sub></i>
      <i>&le;</i> <i>t<sub>i</sub></i> <i>&le;</i>
      <i>t<sub>i1</sub></i>; for the <i>i</i>th segment by the
      equation:
    </p>
    <blockquote>
      <p>
        <img src=""figures/IfcCompositeCurve-Math2.gif"" width=
        ""140"" height=""60""> if <i>Segments[i].SameSense</i> =
        TRUE;
      </p>
    </blockquote>
    <p>
      or by the equation:
    </p>
    <blockquote>
      <p>
        <img src=""figures/IfcCompositeCurve-Math3.gif"" width=
        ""140"" height=""60""> if <i>Segments[i].SameSense</i> =
        FALSE;
      </p>
    </blockquote>
    <p>
      If the segments[i] is of type reparameterised composite
      curve segment,
    </p>
    <blockquote>
      <p>
        <img src=""figures/IfcCompositeCurve-Math4.gif"" width=
        ""140"" height=""60""> where <i>&tau;</i> is defined at
        reparameterized composite curve segment (see
        <i>IfcReparameterizedCompositeCurveSegment</i>).
      </p>
    </blockquote>
    <p>

<p>Figure 279 illustrates an example of a composite curve.</p>
<table>
<tr><td><img src=""figures/IfcCompositeCurve.png"" width=""600"" height=""260""></td></tr>
<tr><td><p class=""figure"">Figure 279 &mdash; Composite curve</p></td></tr>
</table>

<p>Consider an <i>IfcCompositeCurve</i> having line segment and an arc segment. The line should be parameterized:</p>
      <ul>
        <li><i>IfcPolyline</i> with start= 0.,0. end= 0.,1., <i>SameSense</i>= TRUE, parametric length = 1.</li>
      </ul>
<p>The arch should be parameterized:</p>
      <ul>
        <li><i>IfcTrimmedCurve</i> with start= 180', end= 90', <i>SameSense</i>= FALSE, parametric length = 90.</li>
      </ul>
<p>Then the parameterization of the composite curve is:</p>
      <ul>
        <li><i>IfcCompositeCurve</i> with 0. &le; T &le; 1. (line segment) and 1. &le; T &le; 91. (arc segment), parametric length = 91.</li>
      </ul>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: composite_curve, please refer to ISO/IS 10303-42:1994, p. 56 for the final definition of the formal standard. The WR2 is added to ensure consistent Dim at all segments.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.0
</blockquote>

    <p>
      <u>Informal Propositions</u>:
    </p>
    <ol>
      <li>The <i>SameSense</i> attribute of each segment
      correctly specifies the senses of the component curves.
      When traversed in the direction indicated by
      <i>SameSense</i>, the segments shall join end-to-end.
      </li>
    </ol>

</EPM-HTML>"
5582;IfcCompositeCurveOnSurface;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u> A composite curve on surface is a collection of segments which are curves on a surface. Each segment shall lie on the basis surface.</p>

<p>There shall be at least positional continuity between adjacent segments. The parameterization of the composite curve is obtained from the accumulation of the parametric ranges of the segments. The first segment is parameterized from <i>0</i> to <i>l<sub>1</sub></i>, and, for <i>i &ge; 2</i>, the <i>i<sup>th</sup></i> segment is parameterized from</p>

<blockquote><img src=""figures/IfcCompositeCurveOnSurface-Math1.gif"" alt=""formula"" width=""140"" height=""60""></blockquote>

<p>where <i>l<sub>k</sub></i> is the parametric length (that is, the difference between maximum and minimum parameter values) of the <i>k<sup>th</sup></i> curve segment.</p>

<p>The <i>IfcCompositeCurveOnSurface</i> is a collection of segments, based on p-curves. i.e. a curve which lies on the basis of a surface and is defined in the parameter space of that surface. The p-curve segment is a special type of a composite curve segment and shall only be used to bound a surface.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: composite_curve_on_surface. Please refer to ISO/IS 10303-42:1994, p.64 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5586;IfcBoundaryCurve;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>˙ A boundary curve
is a type of bounded curve suitable for the definition of a
surface boundary.</p>

<blockquote class=""note"">NOTE˙ Corresponding ISO 10303 entity: boundary_curve. Please refer to ISO/IS 10303-42:1994, p.89 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5589;IfcOuterBoundaryCurve;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>˙ This is a special subtype of boundary curve which has the additional semantics of defining an outer boundary of a surface. No more than one such curve shall be included in the set of boundaries of a curve bounded surface.</p>

<blockquote class=""note"">
NOTE˙ Corresponding ISO 10303 entity: outer_boundary_curve. Please refer to ISO/IS 10303-42:1994, p.89 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY˙ New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5590;IfcSurface;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A surface can be envisioned as a set of connected points in 3-dimensional space which is always locally 2-dimensional, but need not be a manifold. </p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 entity: surface, the following subtypes have been incorporated into IFC - elementary_surface (as <i>IfcElementarySurface</i>), swept_surface (as <i>IfcSweptSurface</i>) and bounded_surface (as <i>IfcBoundedSurface</i>). Please refer to ISO/IS 10303-42:1994, p. 68 for the final definition of the formal standard.</p> 

<blockquote class=""history"">
HISTORY New class in IFC Release 1.5
</blockquote>
 
<p><u>Informal proposition</u>:</p> 
<ol> 
<li>A surface has non zero area.</li> 
<li>A surface is arcwise connected.</li> 
</ol> 

</EPM-HTML>"
5595;IfcElementarySurface;"<EPM-HTML>
 
<p><u>Definition from ISO/CD 10303-42:1992</u>: An elementary surface (<i>IfcElementarySurface</i>) is a simple analytic surface with defined parametric representation. </p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: elementary_surface. Only the subtype plane is incorporated as IfcPlane. The derived attribute Dim has been added (see also note at <i>IfcGeometricRepresentationItem</i>). Please refer to ISO/IS 10303-42:1994, p. 69 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.5
</blockquote>

</EPM-HTML>"
5599;IfcPlane;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A plane is an unbounded surface with a constant normal. A plane is defined by a point on the plane and the normal direction to the plane. The data is to be interpreted as follows:</p>

<blockquote>
<blockquote>
<pre>
C = Position.Location
x = Position.P[1]
y = Position.P[2]
z = Position.P[3] =&gt; normal to plane
</pre></blockquote>
</blockquote>
<p>and the surface is parameterized as:</p>
<blockquote>
<blockquote>
<p><img src=""figures/IfcPlane-Math1.gif.gif"" alt=""formula"" width=
""141"" height=""21""></p>
</blockquote>
</blockquote>
<p>where the parametric range is -&infin; &lt; <i>u,v</i> &lt;
&infin;. In the above parameterization the length unit for the
unit vectors <b>x</b> and <b>y</b> is derived from the context of
the plane.</p>

<p>The planar surface is an unbounded surface in the direction of <i>x</i> and <i>y</i>. Bounded planar surfaces are defined by using a subtype of <i>IfcBoundedSurface</i> with <i>BasisSurface</i> being a plane.</p>

<blockquote><small>NOTE A rectangular bounded planar surface can
be defined by an <i>IfcRectangularTrimmedSurface</i> with
<i>BasisSurface</i> being the plane and <i>U1</i> = left bound in
<b>x</b>, <i>U2</i> = right bound in <b>x</b>, <i>V</i>1 = lower
bound in <b>y</b>, <i>V2</i> = upper bound in <b>y</b> if viewed
into the direction of the negative normal. (assuming the
<i>Usense</i> and <i>Vsense</i> agree to the sense of the basis
surface).</small></blockquote>
<p>The inherited attributes are interpreted as</p>
<ul>
<li><i>SELF\IfcElementarySurface.Position</i> defines the
location and orientation of the planar surface.</li>
<li><i>SELF\IfcElementarySurface.Position.Location</i> defines a
point on the planar surface.</li>
<li><i>SELF\IfcElementarySurface.Position.P[3]</i> defines the
normal of the planar surface.</li>
</ul>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: plane. Please refer to ISO/IS 10303-42:1994, p.69 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.5
</blockquote>

</EPM-HTML>"
5600;IfcCylindricalSurface;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A cylindrical surface is a surface at a constant distance (the radius) from a straight line. A cylindrical surface is defined by its radius and its orientation and location. The data is to be interpreted as follows:</p>

<blockquote>
<blockquote>
<pre>
C = Position.Location
x = Position.P[1]
y = Position.P[2]
z = Position.P[3]
<i>R</i> = Radius
</pre></blockquote>
</blockquote>
<p>and the surface is parameterized as:</p>
<blockquote>
<blockquote>
<p><img src=""figures/IfcCylindricalSurface-Math1.gif"" width=""300""
height=""25""></p>
</blockquote>
</blockquote>
<p>where the parametric range is -&infin; &lt; <i>u,v</i> &lt;
&infin; .</p>
<p>In the above parameterization the length unit for the unit
vectors <b>z</b> is equal to that of the radius <b><i>R</i></b>.
In the placement coordinate system defined above, the surface is
represented by the equation <i>S</i> = 0, where</p>
<blockquote>
<blockquote>
<p><img src=""figures/IfcCylindricalSurface-Math2.gif"" width=""200""
height=""25""></p>
</blockquote>
</blockquote>
<p>The positive direction of the normal to the surface at any
point on the surface is given by</p>
<blockquote>
<blockquote>
<p><img src=""figures/IfcCylindricalSurface-Math3.gif"" width=""100""
height=""25"">, or as unit normal by</p>
<p><img src=""figures/IfcCylindricalSurface-Math4.gif"" width=""220""
height=""25""></p>
</blockquote>
</blockquote>

<p>The direction of the normal is away from the axis of the cylinder.</p>

<p>The cylindrical surface is a surface unbounded in the direction of <i>z</i>. Bounded cylindrical surfaces are defined by using a subtype of <i>IfcBoundedSurface</i> with <i>BasisSurface</i> being a cylindrical surface.</p>

<blockquote><small>NOTE A bounded cylindrical surface can be
defined by an <i>IfcRectangularTrimmedSurface</i> with
<i>BasisSurface</i> being the cylindrical surface and <i>U1</i> =
0&deg;, <i>U2</i> = 360&deg; and <i>V1</i> = lower bound in
<b>z</b>, <i>V2</i> = upper bound in <b>z</b> (if the plane angle
measure is degree). A bounded cylindrical arc surface is provided
with |U1 - U2| &lt; 360&deg; (assuming the Usense and Vsense
agree to the sense of the basis surface).</small></blockquote>
<blockquote><small>NOTE A non-rectangular bounded cylindrical
surface, e.g. the surface of a round wall underneath a sloped
roof, cab be defined by an <i>IfcCurveBoundedSurface</i> with
<i>IfcBoundaryCurve</i>'s, being a collection of p-curve
segments. A p-curve is curve which lies on the basis of a surface
and is defined in the parameter space of that
surface.</small></blockquote>

<p>The inherited attributes are interpreted as</p>
<ul>
<li><i>SELF\IfcElementarySurface.Position</i> defines the
location and orientation of the cylindrical surface.</li>
<li><i>SELF\IfcElementarySurface.Position.Location</i> definesd a
point on the axis of the cylindrical surface.</li>
<li><i>SELF\IfcElementarySurface.Position.P[3]</i> defines the
direction of the axis of the cylindrical surface.</li>
</ul>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: plane. Please refer to ISO/IS 10303-42:1994, p.70 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC2x4.
</blockquote>

</EPM-HTML>"
5602;IfcAxis2Placement3D;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: The location and orientation in three dimensional space of three mutually perpendicular axes. An axis2_placement_3D is defined in terms of a point (inherited from placement supertype) and two (ideally orthogonal) axes. It can be used to locate and originate an object in three dimensional space and to define a placement coordinate system. The entity includes a point which forms the origin of the placement coordinate system. Two direction vectors are required to complete the definition of the placement coordinate system. The axis is the placement Z axis direction and the ref_direction is an approximation to the placement X axis direction.</p>

<p>If the attribute values for <i>Axis</i> and <i>RefDirection</i>
are not given, the placement defaults to P[1] (x-axis) as [1.,0.,0.],
P[2] (y-axis) as [0.,1.,0.] and P[3] (z-axis) as [0.,0.,1.].</p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: axis2_placement_3d, please refer to ISO/IS 10303-42:1994 for the final definition of the formal standard. The WR5 is added to ensure that either both attributes <i>Axis</i> and <i>RefDirection</i> are given, or both are omitted.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5.
</blockquote>

<p>Figure 276 illustrates the definition of the <i>IfcAxis2Placement3D</i> within the three-dimensional coordinate system.</p>
<table>
<tr><td><img src=""figures/IfcAxis2Placement3D-Layout1.gif"" alt=""axis2 placement 2D"" border=""0"" height=""300"" width=""400""></td></tr>
<tr><td><p class=""figure"">Figure 276 &mdash; Axis2 placement 3D</p></td></tr>
</table>

</EPM-HTML>"
5611;IfcSweptSurface;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</U>: A swept surface is one that is constructed by sweeping a curve along another curve. </p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: swept_surface. Please refer to ISO/IS 10303-42:1994, p.76 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 2x.
</blockquote>

</EPM-HTML>"
5618;IfcSurfaceOfRevolution;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A surface of revolution (<i>IfcSurfaceOfRevolution</i>) is the surface obtained by rotating a curve one complete revolution about an axis. The data shall be interpreted as below. </p>
	 
<p>The parameterization is as follows where the curve has a parameterization <FONT FACE=""Symbol"">l</FONT>(<i>u</i>):</p> 

<blockquote><blockquote> 
<p><b>C</b> = AxisPosition.Location<BR><B>V</B> = AxisPosition.Z</p>
<p><img src=""figures/IfcSurfaceOfResolution-Math1.gif"" width=""494"" height=""22""></p>
</blockquote></blockquote> 

<p>In order to produce a single-value surface the a complete revolution, the curve shall be such that when expressed in a cylindrical coordinate system the curve shall be such that when expressed in a cylindrical coordinate system (<i>r,&phi; ,z</i>) centred at C with an axis V no two distinct parametric points on the curve shall have the same values for (<i>r, z</i>). </p> 
<p>For a surface of revolution the parametric range is 0 &lt; <i>u</i> &lt; 360 degree. The parameterization range for <i>v</i> is defined by referenced curve.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: surface_of_revolution. Please refer to ISO/IS 10303-42:1994, p.76 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x.
</blockquote> 

<p><u>Informal propositions</u>:</p> 
<ol> 
<li>The surface shall not self-intersect</li> 
<li>The swept curve shall not be coincident with the axis line for any finite part of its legth.</li> 
</ol>

</EPM-HTML>"
5621;IfcAxis1Placement;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: The direction and location in three dimensional space of a single axis. An axis1_placement is defined in terms of a locating point (inherited from placement supertype) and an axis direction: this is either the direction of axis or defaults to (0.0,0.0,1.0). The actual direction for the axis placement is given by the derived attribute z (Z). </p> 

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 name: axis1_placement, please refer to ISO/IS 10303-42:1994, p. 28 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC Release 1.5
</blockquote> 

<p>Figure 274 illustrates the definition of the <i>IfcAxis1Placement</i> within the three-dimensional coordinate system.</p>
<table> 
<tr><td><img src=""figures/IfcAxis1Placement-Layout1.gif"" alt=""axis1 placement"" width=""400"" height=""300"" border=""0""></td></tr> 
<tr><td><p class=""figure"">Figure 274 &mdash; Axis1 placement</p></td></tr>
</table>

</EPM-HTML>"
5626;IfcLine;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A line is an unbounded curve with constant tangent direction. A line is defined by a point and a direction. The positive direction of the line is in the direction of the Dir vector. The line is parameterized as follows:</p>

    <blockquote>
        <b>P</b> = Pnt<br>
        <b>V</b> = Dir<br>
        &lambda;(<i>u</i>) = <b>P</b> + <i>u</i><b>V</b>
    </blockquote>
    <p>
      and the parametric range is:
    </p>
    <blockquote>
	&infin; &lt; <i>u</i> &lt; &infin;
    </blockquote>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: line. Please refer to ISO/IS 10303-42:1994, p.37 for the final definition of the formal standard. The derived attribute <i>Dim</i> has been added at this level and was therefore demoted from the geometric_representation_item.
</blockquote>

<blockquote>
HISTORY New class in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5630;IfcVector;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: The vector is defined in terms of the direction and magnitude of the vector. The value of the magnitude attribute defines the magnitude of the vector.</p> 

<blockquote class=""note""> 
NOTE: The magnitude of the vector can not be reliable calculated from the components of the Orientation attribute. This form of representation was selected to reduce problems with numerical instability. For example a vector of magnitude 2.0 mm and equally inclined to the coordinate axes could be represented with Orientation attribute of (1.0,1.0,1.0).
</blockquote> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: vector. Please refer to ISO/IS 10303-42:1994, p.27 for the final definition of the formal standard. The derived attribute <I>Dim</I> has been added (see also note at <I>IfcGeometricRepresentationItem</I>).
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5635;IfcSurfaceOfLinearExtrusion;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: This surface is a simple swept surface or a generalized cylinder obtained by sweeping a curve in a given direction. The parameterization is as follows where the curve has a parameterization <FONT FACE=""Symbol"">l</FONT>(<I>u</I>):</p> 

<blockquote><blockquote><p>V = ExtrusionAxis</p> 
<p><img src=""figures/IfcSurfaceOfLinearExtrusion-Math1.gif"" width=""124"" height=""22""></p>
</blockquote></blockquote> 

<p>The parameterization range for <I>v</I> is -<FONT FACE=""Symbol"">&yen;</FONT> &lt; <i>v</i> &lt; <FONT FACE=""Symbol"">&yen;</FONT> and for <I>u</I> it is defined by the curve parameterization.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: surface_of_linear_extrusion. Please refer to ISO/IS 10303-42:1994, p.76 for the final definition of the formal standard. The following adaption has been made. The <i>ExtrusionAxis</i> and the <i>Direction</i> are defined as two separate attributes in correlation to the definition of the extruded_area_solid, and not as a single vector attribute. The vector is derived as <i>ExtrusionAxis</i>.
</blockquote>

<blockquote class=""history""> 
HISTORY: New entity in IFC Release 2x.
</blockquote> 

<p><u>Informal propositions</u>:</p> 
<ol> 
<li>The surface shall not self-intersect</li> 
</ol>

</EPM-HTML>"
5640;IfcBoundedSurface;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A bounded surface is a surface of finite area with identifiable boundaries.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: bounded_surface. Please refer to ISO/IS 10303-42:1994, p.78 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2x
</blockquote>

<blockquote class=""change-ifc2x4"">
IFC2x4 CHANGE Entity made abstract.
</blockquote>

<p><u>Informal propositions</u>:</p>
<ol>
<li>A bounded surface has finite non-zero surface area.</li>
<li>A bounded surface has boundary curves.</li>
</ol>

</EPM-HTML>"
5645;IfcCurveBoundedPlane;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: The curve bounded surface is a parametric surface with curved boundaries defined by one or more boundary curves. The bounded surface is defined to be the portion of the basis surface in the direction of N x T from any point on the boundary, where N is the surface normal and T the boundary curve tangent vector at this point. The region so defined shall be arcwise connected. </p>

<p>The <i>IfcCurveBoundedPlane</i> is a specialized bounded surface class that deals only with bounding basis plane surfaces. The definition varies from STEP as outer and inner boundaries are separated attributes and refer to <i>IfcCurve</i>. The only basis surface that is allowed is of type <i>IfcPlane</i>, and the implicit_outer attribute has not been incorporated, since only unbounded surfaces are used as basis surface.</p>

<p>The <i>BasisSurface</i> is an <i>IfcPlane</i> that establishes the position coordinate system by <i>SELF\IfcElementarySurface.Position</i>. The <i>OuterBoundary</i> and the <i>InnerBoundaries</i> (if provided) shall lie on the surface of <i>IfcPlane</i>. Therefore the <i>IfcCurve</i>'s establishing the outer and inner boundaries shall be:</p>

<ul> 
<li>either a 2D curve within the XY plane of the position coordinate sytem of <i>IfcPlane</i></li> <li>or a 3D curve with all coordinates having a z value = 0.</li>
</ul>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity curve_bounded_surface has been changed to meet the specific requirements of an easy representation of curve bounded planes.
</blockquote>

<blockquote class=""history"">
HISTORY &nbsp;New entity in IFC Release 1.5
</blockquote>

<blockquote class=""change-ifc2x"">
IFC2x PLATFORM CHANGE: The data type of the attribute <i>OuterBoundary</i> and <i>InnerBoundaries</i> has been changed from <i>Ifc2DCompositeCurve</i> to its supertype <i>IfcCurve</i> with upward compatibility for file based exchange.
</blockquote>

</EPM-HTML>"
5649;IfcRectangularTrimmedSurface;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: The trimmed surface is a simple bounded surface in which the boundaries are the constant parametric lines <i>u</i><sub>1</sub> = u1, <i>u</i><sub>2</sub> = u2, <i>v</i><sub>1</sub> = v1 and <i>v</i><sub>2</sub> = v2. All these values shall be within the parametric range of the referenced surface. Cyclic properties of the parameter range are assumed.</p>

<blockquote class=""note"">
NOTE 1 For example, 370 degrees is equivalent to 10 degrees, for those surfaces whose parametric form is defined using circular functions (sine and cosine).
</blockquote>

<p>The rectangular trimmed surface inherits its parameterization directly from the basis surface and has parameter ranges from 0 to |<i>u</i><sub>2</sub> - <i>u</i><sub>1</sub>| and 0 to|<i>v</i><sub>2</sub>-<i>v</i><sub>1</sub>|.</p>

<blockquote class=""note"">
NOTE 2 If the surface is closed in a given parametric direction, the values of <i>u</i><sub>2</sub> or <i>v</i><sub>2</sub> may require to be increased by the cyclic range.
</blockquote> 

<blockquote class=""note"">
NOTE Corresponding ISO 10303 name: rectangular_trimmed_surface. Please refer to ISO/IS 10303-42:1994, p.86 for the final definition of the formal standard.
</blockquote> 

<blockquote class=""history"">
HISTORY New class in IFC Release 2x.
</blockquote>

<p><u>Informal propositions</u>:</p> 
<ol> 
<li>The domain of the trimmed surface shall be within the domain of the surface being trimmed.</li> 
</ol> 

</EPM-HTML>"
5661;IfcCurveBoundedSurface;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u> The curve bounded surface is a parametric surface with curved boundaries defined by one or more boundary curves. One of the boundary curves may be the outer boundary; any number of inner boundaries is permissible. The region of the curve bounded surface in the basis surface is defined to be the portion of the basis surface in the direction of <b><i>N</i> x <i>T</i></b> from any point on the boundary, where <b>N</b> is the surface normal and <b>T</b> the boundary curve tangent vector at this point. The region so defined shall be arcwise connected.</p>

<p>The <i>IfcCurveBoundedSurface</i> is a parametric surface with boundaries defined by p-curves, that is, a curve which lies on the basis of a surface and is defined in the parameter space of that surface. The p-curve is a special type of a composite curve segment and shall only be used to bound a surface.</p>

<p>The outer boundary shall be either defined by:</p>
<ul>
<li>an <i>IfcOuterBoundaryCurve</i>, a closed composite curve on surface for the definition of an outer boundary, then the attribute <i>ImplicitOuter</i> has to be set to FALSE, or</li>
<li>by the implicit boundary of the bounded surface, e.g. the u1, u2, v1, v2 of <i>IfcRectangularTrimmedSurface</i>&lt; then the attribute <i>ImplicitOuter</i> has to be set to TRUE.
<blockquote><small>Note that some surfaces, like
<i>IfcCylindricalSurface</i> does not have identifiable implicit
boundaries.</small></blockquote>
</li>
</ul>

<blockquote class=""note"">
NOTE Corresponding STEP entity: curve_bounded_surface. Please refer to ISO/IS 10303-42:1994, p.87 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

<p><u>Informal Propositions</u></p>
<ol>
<li>Each curve in the set of <i>Boundaries</i> shall be closed.</li>
<li>No two curves in the set of <i>Boundaries</i> shall intersect.</li>
<li>At most one of the boundary curves may enclose any other boundary curve. If an <i>IfcOuterBoundaryCurve</i> is designated, only that curve may enclose any other boundary curve.</li>
</ol>

</EPM-HTML>"
5665;IfcBSplineSurface;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A b_spline_surface is a general form of rational or polynomial parametric surface which is represented by control points, basis functions, and possibly, weights. As with the corresponding curve entity it has some special subtypes where some of the data can be derived.</p>

<ol style=""list-style-type:lower-roman;"">
<li>The symbology used here is:
<table border=""0"" cellpadding=""2"" cellspacing=""0"" summary=
""symbology"">
<tr>
<td align=""right"" width=""100""><i>K</i>1</td>
<td align=""left"">= upper_index_on_u_control_points</td>
</tr>
<tr>
<td align=""right"" width=""100""><i>K</i>2</td>
<td align=""left"">= upper_index_on_v_control_points</td>
</tr>
<tr>
<td align=""right"" width=""100""><b>P</b><sub>ij</sub></td>
<td align=""left"">= control_points</td>
</tr>
<tr>
<td align=""right"" width=""100"">w<sub>ij</sub></td>
<td align=""left"">= weights</td>
</tr>
<tr>
<td align=""right"" width=""100""><i>d</i>1</td>
<td align=""left"">= u_degree</td>
</tr>
<tr>
<td align=""right"" width=""100""><i>d</i>2</td>
<td align=""left"">= v_degree</td>
</tr>
</table>
<br></li>
<li>The control points are ordered as
<blockquote>P<sub>00</sub>, P<sub>01</sub>, P<sub>02</sub>,
......, P<sub><i>K</i>1(<i>K</i>2-1)</sub>,
P<sub><i>K</i>1<i>K</i>2</sub></blockquote>
The weights, in the case of the rational subtype, are ordered
similarly.<br>
<br></li>
<li>For each parameter, <i>s</i> = <i>u</i> or <i>v</i>, if
<i>k</i> is the upper index on the control points and <i>d</i> is
the degree for <i>s</i>, the knot array is an array of (<i>k</i>
+ <i>d</i> + 2) real numbers [s<sub>-d</sub>, ....,
s<sub><i>k</i>+1</sub>], such that for all indices j in
[-<i>d</i>, <i>k</i>]; <i>s</i><sub><i>j</i></sub> &le;
<i>s</i><sub><i>j</i>+1</sub>. This array is obtained from the
appropriate u_knots or v_knots list by repeating each multiple
knot according to the multiplicity.<br>
<br>
N<sub><i>i</i></sub><sup><i>d</i></sup>, the <i>i</i>th
normalised B-spline basis function of degree <i>d</i>, is defined
on the subset [<i>s</i><sub>i-<i>d</i></sub>, ....,
<i>s</i><sub><i>i</i>+1</sub>] of this array.<br>
<br></li>
<li>Let <i>L</i> denote the number of distinct values amongst the
knots in the knot list; <i>L</i> will be referred to as the
&lsquo;upper index on knots&rsquo;. Let
<i>m</i><sub><i>j</i></sub> denote the multiplicity (i.e., number
of repetitions) of the <i>j</i>th distinct knot value. Then:
<blockquote><img src=""figures/IfcBSplineCurve-Math2.gif"" alt=
""formula"" border=""0""></blockquote>
All knot multiplicities except the first and the last shall be in
the range 1, ...., <i>d</i>; the first and last may have a
maximum value of <i>d</i>+1. In evaluating the basis functions, a
knot <i>u</i> of, e.g., multiplicity 3 is interpreted as a
sequence <i>u</i>, <i>u</i>, <i>u</i>, in the knot array.<br>
<br></li>
<li>The surface form is used to identify specific quadric surface
types (which shall have degree two), ruled surfaces and surfaces
of revolution. As with the b-spline curve, the surface form is
informational only and the spline data takes precedence.<br>
<br></li>
<li>The surface is to be interpreted as follows: In the
polynomial case the surface is given by the equation:
<blockquote><img src=""figures/IfcBSplineSurface-Math1.gif"" alt=
""formula"" border></blockquote>
In the rational case the surface equation is:
<blockquote><img src=""figures/IfcBSplineSurface-Math2.gif"" alt=
""formula"" border></blockquote>
</li>
</ol>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: b_spline_surface. Please refer to ISO/IS 10303-42:1994, p. 78 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5679;IfcBSplineSurfaceWithKnots;"<EPM-HTML>

<p><u>Definition from ISO 10303:42:1994</u>: This is a B-spline surface in which the knot values are explicitly given. This subtype shall be used to represent non-uniform B-spline surfaces, and may also be used for other knot types.</p>

<p>All knot multiplicities except the first and the last shall be in the range 1,....,<i>d</i>; the first and last may have a maximum value of <i>d</i> + 1. In evaluating the basis functions, a knot <i>u</i> of, e.g., multiplicity 3 is interpreted as a sequence <i>u</i>, <i>u</i>, <i>u</i>, in the knot array.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: b_spline_surface_with_knots. Please refer to ISO/IS 10303-42:1994, p. 81 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5692;IfcRationalBSplineSurfaceWithKnots;"<EPM-HTML>

<p>A rational B-spline surface with knots is a piecewise parametric rational surface described in terms of control points, and associated weight values.</p>

<p>The surface is to be interpreted as follows:</p>

<blockquote>
<big>&sigma;</big><img align=""middle"" src=""figures/IfcBSplineSurface-Math2.gif"" alt=""formula"" border>
</blockquote>

<blockquote class=""note"">
NOTE: The <i>IfcRationalBSplineSurfaceWithKnots</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration &mdash; Product data representation and exchange, Part 42: Integrated generic resource: Geometric and topological representation.
</blockquote>

<blockquote class=""note"">
NOTE: The specific subtype <i>IfcRationalBSplineSurfaceWithKnots</i> has been introduced to avoid the complexity of ANDOR subtype relationships in the ISO 10303-42 specification</small></blockquote>
</blockquote>

<blockquote class=""note"">
NOTE: Corresponding ISO 10303 entity: rational_b_spline_surface. Please refer to ISO/IS 10303-42:1994, p. 85 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5716;IfcCompositeCurveSegment;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A composite curve segment is a bounded curve together with transition information which is used to construct a composite curve (<i>IfcCompositeCurve</i>).</p>

<p>The derived attribute Dim has been added (see also note at <i>IfcGeometricRepresentationItem</i>). The <i>IfcCompositeCurveSegment</i> is a subtype of <i>IfcGeometricRepresentationItem</i> (whereas in ISO 10303-42 composite_curve_segment is not a subtype of geometric_representation_item, the proposed 2nd edition of ISO 10303-42 however proposes the subtype relationship).</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: composite_curve_segment. Please refer to ISO/IS 10303-42:1994, p.57 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5724;IfcReparametrisedCompositeCurveSegment;"<EPM-HTML>
    <p>
      <u>Definition from ISO/CD 10303-42:1992</u>: The
      reparametrised composite curve segment is a special type of
      composite curve segment which provides the capability to
      re-define its parametric length without changing its
      geometry.
    </p>
    <p>
      Let l = <i>ParamLength</i>.
    </p>
    <p>
      If t<sub><small>0</small></sub> &le; t &le;
      t<sub><small>1</small></sub> is the parameter range of
      <i>ParentCurve</i>, the new parameter . for the
      reparametrised composite curve segment is given by the
      equation:
    </p>
    <blockquote>
      <p>
        <img src=
        ""figures/IfcReparametrisedCompositeCurveSegment-Math1.gif""
        width=""100"" height=""60""> if <i>SameSense</i> = TRUE;
      </p>
    </blockquote>
    <p>
      or by the equation:
    </p>
    <blockquote>
      <p>
        <img src=
        ""figures/IfcReparametrisedCompositeCurveSegment-Math2.gif""
        width=""100"" height=""60""> if <i>SameSense</i> = FALSE;
      </p>
    </blockquote>

<blockquote class=""note"">
NOTE Corresponding STEP entity: reparametrised_composite_curve_segment. Please refer to ISO/IS 10303-42:1994, p.59 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY New class in IFC2x4
</blockquote>

</EPM-HTML>"
5732;IfcPolyline;"<EPM-HTML> 
    <p>
      <u>Definition from ISO/CD 10303-42:1992</u>: A polyline
      is a bounded curve of <i>n</i> - 1 linear segments, defined by a
      list of <i>n</i> points, P<sub>1</sub>, P<sub>2</sub> ... P<sub>n</sub>. 
			The <i>i</i>th segment of the curve is parameterized as follows:
    </p>
    <blockquote>
      <blockquote>
        <p>
          <img src=""figures/IfcPolyline-Math1.gif"" width=""190""
          height=""24"" align=""middle"">&nbsp;&nbsp;&nbsp;
					<i>for</i> 1 &le; <i>i</i> &le; <i>n</i> - 1
        </p>
      </blockquote>
    </blockquote>
    <p>
      where <i>i</i> - 1 &le; <i>u</i> &le; <i>i</i> and
      with parametric range of 0 <&le; <i>u</i> &le; <i>n</i> - 1.
    </p>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: polyline. Please refer to ISO/IS 10303-42:1994, p. 45 for the final definition of the formal standard.
</blockquote>
<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5735;IfcTrimmedCurve;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>:
A trimmed curve is a bounded curve which is created by taking a selected
portion, between two identified points, of the associated basis curve.
The basis curve itself is unaltered and more than one trimmed curve may
reference the same basis curve. Trimming points for the curve may be
identified by:</p>
<ul> <li> parametric value </li> <li>geometric
position </li> <li>both of the above </li>
</ul><p>At least one of these shall be specified at each
end of the
curve. The <i>SenseAgreement</i> makes it possible to
unambiguously define any segment of a closed curve such as a circle.
The combinations of sense and ordered end points make it possible to
define four distinct directed segments connecting two different points
on a circle or other closed curve. For this purpose cyclic properties
of the parameter range are assumed; for example, 370 degrees is
equivalent to 10 degrees. </p>
<p>The <i>IfcTrimmedCurve</i> has a parameterization
which is inherited from the particular basis curve reference. More
precisely the parameter s of the trimmed curve is derived from the
parameter of the basis curve as follows: </p>
<ul> <li>if <i>SenseAgreement</i> is TRUE: <i>s
= t - t<sub>1</sub></i></li> <li> if <i>SenseAgreement</i>
is FALSE: <i>s
= t<sub>2</sub> - t</i> </li>
</ul><p>In the above equations t<sub>1</sub> is
the value
given by <i>Trim1</i> or the parameter value corresponding
to point 1 and t<sub>2</sub> is the value given by <i>Trim2</i>
or the parameter value corresponding to point 2. The resultant <i>IfcTrimmedCurve</i>
has a parameter ranging from 0 at the first trimming point to |t<sub>2</sub>
- t<sub>1</sub>| at the second trimming point. </p>
<blockquote> <p><font size=""-1"">NOTE In case
of a closed curve,
it may be necessary to increment t1 or t2 by the parametric length for
consistency with the sense flag.</font></p>
</blockquote>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: trimmed_curve; As a further IFC restriction, an <i>IfcTrimmedCurve</i> should only trim a <i>IfcLine</i> or <i>IfcConic</i>. Please refer to ISO/IS 10303-42:1994, p. 54 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.0
</blockquote>

<p> <u>Informal Propositions</u>:</p>
<ol> <li>Where both the parameter value and the Cartesian
point
exist for <i>Trim1</i> and <i>Trim2</i> they
shall be consistent. (i.e., the <i>BasisCurve</i>
evaluated at the parameter value shall coincide with the specified
point).</li> <li>When a Cartesian point is specified by <i>Trim1</i>
or by <i>Trim2</i> it shall lie on the <i>BasisCurve</i>.</li>
<li>Except the case of a closed <i>BasisCurve</i>
where both parameter 1 and parameter 2 exist, they shall be consistent
with the sense flag, i.e., (sense = parameter 1 &lt; parameter 2). <font
 color=""#0000ff"">Or, for every open curve where both
parameter 1 and parameter 2 exist, they shall be consistent with the <i>SenseAgreement</i>,
i.e., <i>SenseAgreement</i> = (parameter 1 &lt;
parameter 2).</font></li> <li>If both parameter 1
and parameter 2 exist, then parameter 1
&lt;&gt; parameter 2. <font color=""#0000ff"">For a
closed base curve, e.g. <i>IfcCircle</i> or <i>IfcEllipse</i>,
this also applies to the cyclic properties, as 360' is equal to 0',
parameter 1 = 360' and parameter 2 = 0' are treated as being equal and
therefore violating this proposition.</font></li> <li>When
a parameter value is specified by <i>Trim1</i>
or <i>Trim2</i> it shall lie within the parametric range
of the <i>BasisCurve</i>.</li>
</ol><p><u>Additional illustration from IAI:</u></p>
<table> <tbody> <tr> <td><img
 src=""figures/IfcTrimmedCurve_Parameterization.png""
 alt=""curve parameterization"" border=""0"" height=""500""
 width=""700""></td> </tr> <tr> <td>The
figure above shows the four arcs (dashed blue and
green lines with arrow showing different orientations) that can be
defined by the same <i>BasisCurve</i> (of type <i>IfcCircle</i>)
and the same trimming points (given by Cartesian points and parameter
values) by using different assignments to <i>Trim1</i> and
<i>Trim2</i> and <i>SenseAgreement</i>. <font
 color=""#0000ff""><br> <br>
Note: Since the <i>BasisCurve</i> is closed (type <i>IfcCircle</i>),
the exception of the informal proposition IP3 applies, i.e. the sense
flag is not
required to be consistent with the parameter values of <i>Trim1</i>
and <i>Trim1</i>, so the rule (sense = parameter 1
&lt; parameter 2) may not be fulfilled.</font></td> </tr>
</tbody>
</table>

</EPM-HTML>"
5751;IfcBSplineCurve;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A B-spline curve is a piecewise parametric polynomial or rational curve described in terms of control points and basis functions. The B-spline curve has been selected as the most stable format to represent all types of polynomial or rational parametric curves. With appropriate attribute values it is capable of representing single span or spline curves of explicit polynomial, rational, Bezier or B-spline type.</p> 

<p>Interpretation of the data is as follows:</p> 
	 <ol> 
		<li> 
		  <p>All weights shall be positive and the curve is given by</p><img
		  src=""figures/IfcBSplineCurve-Math1.gif"" width=""183"" height=""115"" border=""0""> 
		  <table> 
			 <tr> 
				<td align=""right"" width=""100""><i>k</i>+1</td> 
				<td> = number of control points</td> 
			 </tr> 
			 <tr> 
				<td align=""right"" width=""100"">P<sub><i>i</i></sub></td> 
				<td>= control points</td> 
			 </tr> 
			 <tr> 
				<td align=""right"" width=""100""><i>w</i><sub><i>i</i></sub></td> 
				<td>= weights</td> 
			 </tr> 
			 <tr> 
				<td align=""right"" width=""100""><i>d</i></td> 
				<td>= degree</td> 
			 </tr> 
		  </table> 
		  <p>The knot array is an array of (<i>k</i>+<i>d</i>+2) real numbers
			 [<i>u</i><sub>-<i>d</i></sub> ... <i>u</i><sub><i>k</i>+1</sub>], such that for
			 all indices j in [-<i>d</i>,<i>k</i>], <i>u</i><sub>j</sub> &lt;=
			 <i>u</i><sub>j+1</sub>. This array is obtained from the knot data list by
			 repeating each multiple knot according to the multiplicity. <i>N
			 <sup>d</sup><sub>i</sub></i>, the <i>i</i>th normalized B-spline basis function
			 of degree <i>d</i>, is defined on the subset [<i>u<sub>i-d</sub></i>, ... ,
			 <i>u<sub>i+1</sub></i>] of this array.</p></li> 
		<li> 
		  <p>Let <i>L</i> denote the number of distinct values among the
			 <i>d</i>+<i>k</i>+2 knots in the knot array; <I>L</I> will be referred to as
			 the 'upper index on knots'. Let <i>m<sub>j</sub></i> denote the multiplicity
			 (number of repetitions) of the <i>j</i>th distinct knot. Then</p>
		  <img src=""figures/IfcBSplineCurve-Math2.gif"" width=""149"" height=""59""
			border=""0""> 
		  <p>All knot multiplicities except the first and the last shall be in
			 the range 1 ... degree; the first and last may have a maximum value of degree +
			 1. In evaluating the basis functions, a knot <i>u</i> of e.g. multiplicity 3 is
			 interpreted as a string <i>u, u, u,</i> in the knot array. The B-spline curve
			 has 3 special subtypes (<i>Note: only 1, Bezier curve, included in this IFC
			 release</i>) where the knots and knot multiplicities are derived to provide
			 simple default capabilities.</p></li> 
		<li>Logical flag is provided to indicate whether the curve self
		  intersects or not.</li> 
	 </ol> 
<p>Figure 277 (from ISO 10303-42) illustrates a B-spline curve.</p>
<table>
<tr><td><img src=""figures/IfcBSplineCurve-Fig1.gif"" alt=""control points"" width=""520"" height=""200"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 277 &mdash; B-spline curve</p></td></tr>
</table>

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: b_spline_curve. Please refer to ISO/IS 10303-42:1994, p. 45 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in Release IFC2x2.
</blockquote>

</EPM-HTML>"
5761;IfcBSplineCurveWithKnots;"<EPM-HTML> 

<p><u>Definition from ISO 10303:42:1994</u>: This is the type of b-spline curve for which the knot values are explicitly given. This subtype shall be used to represent non-uniform B-spline curves and may be used for other knot types.</p>

<p>Let <i>L</i> denote the number of distinct values amongst the
<i>d</i>+<i>k</i>+2 knots in the knot list; <i>L</i> will be
referred to as the &lsquo;upper index on knots&rsquo;. Let
<i>m<sub>j</sub></i> denote the multiplicity (i.e., number of
repetitions) of the <i>j</i>th distinct knot. Then:</p>
<blockquote><img src=""figures/IfcBSplineCurve-Math2.gif"" alt=
""formula"" border=""0""></blockquote>

<p>All knot multiplicities except the first and the last shall be
in the range 1,...,<i>d</i>; the first and last may have a
maximum value of <i>d</i> + 1. In evaluating the basis functions,
a knot <i>u</i> of, e.g., multiplicity 3 is interpreted as a
sequence <i>u</i>, <i>u</i>, <i>u</i>,; in the knot array.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: b_spline_curve_with_knots. Please refer to ISO/IS 10303-42:1994, p. 46 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5769;IfcRationalBSplineCurveWithKnots;"<EPM-HTML>
<p>A rational B-spline curve with knots is a B-spline curve
described in terms of control points and basic functions. It
describes weights in addition to the control points defined at the
supertype <i>IfcBSplineCurve</i>.</p>

<blockquote><small>NOTE: The
<i>IfcRationalBSplineCurveWithKnots</i> is an entity that had been
adopted from ISO 10303, Industrial automation systems and
integration &mdash; Product data representation and exchange, Part
42: Integrated generic resource: Geometric and topological
representation.</small></blockquote>

<blockquote><small>NOTE: The specific subtype
<i>IfcRationalBSplineCurveWithKnots</i> has been introduced to
avoid the complexity of ANDOR subtype relationships in the ISO
10303-42 specification</small></blockquote>

<p>All weights shall be positive and the curve is given by:</p>

<blockquote><img src=
""figures/IfcRationalBSplineCurveWithKnots-Math1.gif"" alt=""Math""
border=""0""></blockquote>
<p>where</p>
<table>
<tr>
<td width=""100"" align=""right""><i>k</i>+1</td>
<td>number of control points</td>
</tr>
<tr>
<td align=""right"">P<sub><i>i</i></sub></td>
<td>control points</td>
</tr>
<tr>
<td align=""right""><i>w<sub>i</sub></i></td>
<td>weights</td>
</tr>
<tr>
<td align=""right""><i>d</i></td>
<td>degree</td>
</tr>
</table>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: rational_b_spline_curve. Please refer to ISO/IS 10303-42:1994, p. 45 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New entity in IFC2x4.
</blockquote>

</EPM-HTML>"
5781;IfcConic;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: A conic (<i>IfcConic</i>) is a planar curve which could be produced by intersecting a plane with a cone. A conic is defined in terms of its intrinsic geometric properties rather than being described in terms of other geometry. A conic class always has a placement coordinate system defined by a two or three dimensional placement. The parametric representation is defined in terms of this placement coordinate system.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: conic, only the following subtypes have been incorporated into IFC 1.0, 1.5 &amp; 2.0: circle as <i>IfcCircle</i>, ellipse as <i>IfcEllipse</i>. The derived attribute <i>Dim</i> has been added at this level and was therefore demoted from the geometric_representation_item. Please refer to ISO/IS 10303-42:1994, p. 38 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC Release 1.0
</blockquote>

</EPM-HTML>"
5785;IfcCircle;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: An <i>IfcCircle</i> is defined by a radius and the location and orientation of the circle. Interpretation of data should be as follows:</p> 

	 <blockquote> 
		<blockquote> 
		  <pre> 
C = SELF\IfcConic.Position.Location</pre> 
		  <pre>x = SELF\IfcConic.Position.P[1]</pre> 
		  <pre>y = SELF\IfcConic.Position.P[2]</pre> 
		  <pre>z = SELF\IfcConic.Position.P[3]</pre> 
		  <pre>R = Radius</pre>
                </blockquote></blockquote> 
	 <p>and the circle is parameterized as </p> 
	 <blockquote><blockquote><img src=""figures/IfcCircle-Math1.gif"" width=""205"" height=""22""></blockquote></blockquote> 
	 <p>The parameterization range is 0 <FONT FACE=""Symbol"">&pound;</FONT>
		<I>u</I> <FONT FACE=""Symbol"">&pound;</FONT>2<FONT FACE=""Symbol"">p</FONT> (or 0
		<FONT FACE=""Symbol"">&pound;</FONT><I>u</I> <FONT FACE=""Symbol"">&pound;</FONT>
		360 degree). In the placement coordinate system defined above, the circle is
		the equation <I>C</I> = 0, where</p> 
	 <blockquote><blockquote><img src=""figures/IfcCircle-Math2.gif"" width=""154"" height=""24""></blockquote></blockquote> 
	 <p>The positive sense of the circle at any point is in the tangent direction, <B>T</B>, to the curve at the point, where</p> 
	 <blockquote><blockquote><img src=""figures/IfcCircle-Math3.gif"" width=""102"" height=""25""></blockquote></blockquote> 

<blockquote class=""note""> 
NOTE&nbsp; A circular arc is defined by using the trimmed curve (<i>IfcTrimmedCurve</i>) entity in conjunction with the circle (<i>IfcCircle</i>) entity as the BasisCurve.
</blockquote>

<blockquote class=""note"">
NOTE&nbsp; Corresponding ISO 10303 entity: circle, please refer to ISO/IS 10303-42:1994, p. 38 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 1.0
</blockquote>

<p>Figure 278 illustrates the definition of the <I>IfcCircle</I> within the (in this case three-dimensional) position coordinate system.</p> 

<table> 
<tr><td><img src=""figures/IfcCircle-Layout1.gif"" alt=""axis1 placement"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 278 &mdash; Circle geometry</p></td></tr>
</table>

</EPM-HTML>"
5787;IfcEllipse;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: An ellipse (<i>IfcEllipse</i>) is a conic section defined by the lengths of the semi-major and semi-minor diameters and the position (center or mid point of the line joining the foci) and orientation of the curve. Interpretation of the data shall be as follows:
</p> 

	 <blockquote> 
		<blockquote> 
		  <pre>C  = SELF\IfcConic.Position.Location </pre> 
		  <pre>x  = SELF\IfcConic.Position.P[1] </pre> 
		  <pre>y  = SELF\IfcConic.Position.P[2] </pre> 
		  <pre>z  = SELF\IfcConic.Position.P[3] </pre> 
		  <pre>R1 = SemiAxis1</pre> 
		  <pre>R2 = SemiAxis2</pre></blockquote></blockquote> 
	 <p>and the ellipse is parameterized as: </p> 
	 <blockquote> 
		<blockquote> 
		  <p><img src=""figures/IfcEllipse-Math1.gif"" width=""220"" height=""22""></p></blockquote></blockquote> 
	 <p>The parameterization range is 0 <FONT FACE=""Symbol"">&pound;</FONT>
		<I>u</I> <FONT FACE=""Symbol"">&pound;</FONT> 2<FONT FACE=""Symbol"">p</FONT> (or 0
		<FONT FACE=""Symbol"">&pound;</FONT> <I>u</I> <FONT FACE=""Symbol"">&pound;</FONT>
		360 degree). In the placement coordinate system defined above, the ellipse is
		the equation <I>C</I> = 0, where</P> 
	 <blockquote> 
		<blockquote> 
		  <p><img src=""figures/IfcEllipse-Math2.gif"" width=""193"" height=""24""></p></blockquote></blockquote> 
	 <p>The positive sense of the ellipse at any point is in the tangent direction, T, to the curve at the point, where</p> 
	 <blockquote> 
		<blockquote> 
		  <p><img src=""figures/IfcEllipse-Math3.gif"" width=""102"" height=""25""></p></blockquote></blockquote> 
<p>The inherited Position.Location from IfcConic is the center of the IfcEllipse, and the inherited Position.P[1] from <i>IfcConic</i> the direction of the SemiAxis1. </p> 

<blockquote class=""note""> 
NOTE&nbsp; Corresponding ISO 10303 entity: ellipse. Please refer to ISO/IS 10303-42:1994, p. 39 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY&nbsp; New class in IFC Release 1.0
</blockquote>

<p>Figure 280 illustrates the definition of the IfcEllipse within the (in this case three-dimensional) position coordinate system.</td> 
<table> 
<tr><td><img src=""figures/IfcEllipse-Layout1.gif"" alt=""axis1 placement"" width=""400"" height=""300"" border=""0""></td></tr>
<tr><td><p class=""figure"">Figure 280 &mdash; Ellipse geometry</p></td></tr>
</table> 

</EPM-HTML>"
5790;IfcOffsetCurve2D;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: An offset curve 2d (<i>IfcOffsetCurve2d</i>) is a curve at a constant distance from a basis curve in two-dimensional space. This entity defines a simple plane-offset curve by offsetting by distance along the normal to basis curve in the plane of basis curve. The underlying curve shall have a well-defined tangent direction at every point. In the case of a composite curve, the transition code between each segment shall be cont same gradient or cont same gradient same curvature.</p> 

<blockquote class=""note""> 
NOTE: The offset curve 2d may differ in nature from the basis curve; the offset of a non self- intersecting curve can be self-intersecting. Care should be taken to ensure that the offset to a continuous curve does not become discontinuous.
</blockquote> 

<p>The offset curve 2d takes its parameterization from the basis curve. The offset curve 2d is parameterized as </p> 

<blockquote> 
<p><img src=""figures/IfcOffsetCurve2d-Math1.gif"" alt=""Math"" width=""281"" height=""22"" border=""0""></p>
</blockquote>
 
<p>where <b>T</b> is the unit tangent vector to the basis curve <b>C</b>(<i>u</i>) at parameter value <i>u</i>, and <i>d</i> is distance. The underlying curve shall be two-dimensional.</p> 

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 entity: offset_curve_2d, Please refer to ISO/IS 10303-42:1994, p.65 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2.x
</blockquote>

</EPM-HTML>"
5795;IfcOffsetCurve3D;"<EPM-HTML> 

<p><u>Definition from ISO/CD 10303-42:1992</u>: An offset curve 3d is a curve at a constant distance from a basis curve in three-dimensional space. The underlying curve shall have a well-defined tangent direction at every point. In the case of a composite curve the transition code between each segment shall be cont same gradient or cont same gradient same curvature. The offset curve at any point (parameter) on the basis curve is in the direction <i>V x T</i> where <i>V</i> is the fixed reference direction and <i>T</i> is the unit tangent to the basis curve. For the offset direction to be well defined, <i>T</i> shall not at any point of the curve be in the same, or opposite, direction as <i>V</i>.</p> 

<blockquote class=""note""> 
NOTE: The offset curve 3d may differ in nature from the basis curve; the offset of a non self- intersecting curve can be self-intersecting. Care should be taken to ensure that the offset to a continuous curve does not become discontinuous.
</blockquote> 

<p>The offset curve 3d takes its parameterization from the basis curve. The offset curve 3d is parameterized as </p> 

<blockquote> 
<p><img src=""figures/IfcOffsetCurve3d-Math1.gif"" alt=""Math"" border=""0"" width=""134"" height=""22""></p>
</blockquote> 

<p>where <b>T</b> is the unit tangent vector to the basis curve <b>C</b>(<i>u</i>) at parameter value <i>u</i>, and <i>d</i> is distance. The underlying curve shall be three-dimensional.</p>

<blockquote class=""note""> 
NOTE Corresponding ISO 10303 entity: offset_curve_3d, Please refer to ISO/IS 10303-42:1994, p.66 for the final definition of the formal standard.
</blockquote>

<blockquote class=""history"">
HISTORY New entity in IFC Release 2.x
</blockquote>

<p><u>Informal propositions:</u></p> 
<ol>
<li>At no point on the curve shall ref direction be parallel, or opposite to, the direction of the tangent vector.</li>
</ol> 

</EPM-HTML>"
5801;IfcPCurve;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A pcurve is a curve which lies on the basis of a surface and is defined in the parameter space of that surface. The basis curve is a curve defined in the two-dimensional parametric space of a reference basis surface. Although it is defined by a curve in two dimensional space, the variables involved are <i>u</i> and <i>v</i>, which occur in the parametric representation of the referenced surface, rather than the <i>x</i>, <i>y</i>, Cartesian coordinates.</p>

<p>The basis curve is only defined within the parametric range of the surface.</p>

<blockquote class=""note"">
NOTE Corresponding ISO 10303 entity: pcurve. Please refer to ISO/IS 10303-42:1994, p.59 for the final definition of the formal standard.<br> The definition of <i>IfcPCurve</i> derivates from pcurve. The following changes have been made: The <i>BasisCurve</i> replaces the definition of reference_to_curve since there is no requirement of having same dimensionality within the representation context.
</blockquote>

<blockquote class=""history"">
HISTORY New class in IFC2x4.
</blockquote>

</EPM-HTML>"
5805;IfcPointOnSurface;"<EPM-HTML>

<p><u>Definition from ISO/CD 10303-42:1992</u>: A point on surface is a point which lies on a parametric surface. The point is determined by evaluating the surface at a particular pair of parameter values.</p> 

<blockquote class=""note""> 
NOTE: Corresponding ISO 10303 entity: point_on_surface. Please refer to ISO/IS 10303-42:1994, p. 24 for the final definition of the formal standard. </FONT></P> 
</blockquote>

<blockquote class=""history"">
HISTORY: New entity in Release IFC2x Edition 2.
</blockquote>

<p><u>Informal Propositions</u>:</p> 
<ol>
<li>The parametric values specified for u and v shall not be outside the parametric range of the basis surface.</li>
</ol>

</EPM-HTML>"
