IfcBuildingElementProxy

Natural language names
Bauteil / Bauelement - beliebig
Building Element Proxy
Elément de construction non défini
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcBuildingElementProxyMOVEDSchema changed from IFCPRODUCTEXTENSION to IFCSHAREDBLDGELEMENTS.
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      PredefinedTypeMODIFIEDName changed from CompositionType to PredefinedType.
Type changed from IfcElementCompositionEnum to IfcBuildingElementProxyTypeEnum.
IFC4x2 DRAFT 1
    IfcBuildingElementProxy
      PositionedRelativeToADDED
Semantic definitions at the entity
Entity definition

The IfcBuildingElementProxy is a proxy definition that provides the same functionality as subtypes of IfcBuildingElement, 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 are later replaced by special types of elements.

One use of the proxy object is a provision for voids, i.e. where a particular volume of space is requested by an engineering function that might later be accepted or rejected. If accepted it is transformed into a void within a building element, like a wall opening, or a slab opening. The provision for voids is exchanged as an IfcBuildingElementProxy with the PredefinedType = ProvisionForVoid. Such proxy shall have a swept solid geometry, where the profile of the swept solid lies on/near the surface of the referred building element and the extrusion depths is equal to or bigger then (in case of round or otherwise irregular element shape) the thickness of the building element. The appropriate property set should be attached.

In addition to the provision for voids, the building element proxy can also represent a provision for space, often the necessary space allocation for mechanical equipment that will be determined in a later design phase. The provision for space is exchanged as an IfcBuildingElementProxy with the PredefinedType = ProvisionForSpace.

Other usages of IfcBuildingElementProxy include:

HISTORY  New entity in IFC2x.
Attribute definitions
#AttributeTypeCardinalityDescription G
9PredefinedTypeIfcBuildingElementProxyTypeEnum? Predefined generic type for a building element proxy that is specified in an enumeration. There may be a property set given specificly for the predefined types.
NOTE  The PredefinedType shall only be used, if no IfcBuildingElementProxyType is assigned, providing its own IfcBuildingElementProxyType.PredefinedType.
IFC4 CHANGE  The attribute CompositionType has been replaced by PredefinedType, being a superset of the enumerators.
X
Formal Propositions
RuleDescription
HasObjectNameA Name attribute should be asserted for a building element proxy.
CorrectPredefinedTypeEither the PredefinedType attribute is unset (e.g. because an IfcBuildingElementProxyType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
CorrectTypeAssignedEither there is no building element proxy type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcBuildingElementProxyType.
Inherited definitions from supertypes
Entity inheritance IfcBuildingElement IfcElement IfcProduct IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRoot
1GlobalIdIfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory? Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object,
NOTE  only the last modification in stored - either as addition, deletion or modification.
IFC4 CHANGE  The attribute has been changed to be OPTIONAL.
X
3NameIfcLabel? Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. X
4DescriptionIfcText? Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@RelatedObjects
S[0:?]Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.X
NestsIfcRelNests
@RelatedObjects
S[0:1]References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
X
IsNestedByIfcRelNests
@RelatingObject
S[0:?]References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
X
HasContextIfcRelDeclares
@RelatedDefinitions
S[0:1]References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object.
IFC4 CHANGE  The inverse attribute datatype has been added.
X
IsDecomposedByIfcRelAggregates
@RelatingObject
S[0:?]References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
X
DecomposesIfcRelAggregates
@RelatedObjects
S[0:1]References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
X
HasAssociationsIfcRelAssociates
@RelatedObjects
S[0:?]Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.X
IfcObject
5ObjectTypeIfcLabel? The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
X
IsDeclaredByIfcRelDefinesByObject
@RelatedObjects
S[0:1]Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
X
DeclaresIfcRelDefinesByObject
@RelatingObject
S[0:?]Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
X
IsTypedByIfcRelDefinesByType
@RelatedObjects
S[0:1]Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type.
IFC4 CHANGE  New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
X
IsDefinedByIfcRelDefinesByProperties
@RelatedObjects
S[0:?]Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object.
IFC4 CHANGE  The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
X
IfcProduct
6ObjectPlacementIfcObjectPlacement? Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system.X
7RepresentationIfcProductRepresentation? Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement.X
ReferencedByIfcRelAssignsToProduct
@RelatingProduct
S[0:?]Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.X
PositionedRelativeToIfcRelPositions
@RelatedProducts
S[0:1]X
IfcElement
8TagIfcIdentifier? The tag (or label) identifier at the particular instance of a product, e.g. the serial number, or the position number. It is the identifier at the occurrence level.X
FillsVoidsIfcRelFillsElement
@RelatedBuildingElement
S[0:1]Reference to the IfcRelFillsElement Relationship that puts the element as a filling into the opening created within another element. X
ConnectedToIfcRelConnectsElements
@RelatingElement
S[0:?]Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to. X
IsInterferedByElementsIfcRelInterferesElements
@RelatedElement
S[0:?]Reference to the interference relationship to indicate the element that is interfered. The relationship, if provided, indicates that this element has an interference with one or many other elements.
NOTE  There is no indication of precedence between IsInterferedByElements and InterferesElements.
IFC4 CHANGE New inverse relationship.
X
InterferesElementsIfcRelInterferesElements
@RelatingElement
S[0:?]Reference to the interference relationship to indicate the element that interferes. The relationship, if provided, indicates that this element has an interference with one or many other elements.
NOTE  There is no indication of precedence between IsInterferedByElements and InterferesElements.
IFC4 CHANGE New inverse relationship.
X
HasProjectionsIfcRelProjectsElement
@RelatingElement
S[0:?]Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement.X
ReferencedInStructuresIfcRelReferencedInSpatialStructure
@RelatedElements
S[0:?]Reference relationship to the spatial structure element, to which the element is additionally associated. This relationship may not be hierarchical, an element may be referenced by zero, one or many spatial structure elements.
IFC2x3 CHANGE  The inverse attribute has been added with upward compatibility for file based exchange.
X
HasOpeningsIfcRelVoidsElement
@RelatingBuildingElement
S[0:?]Reference to the IfcRelVoidsElement relationship that creates an opening in an element. An element can incorporate zero-to-many openings. For each opening, that voids the element, a new relationship IfcRelVoidsElement is generated. X
IsConnectionRealizationIfcRelConnectsWithRealizingElements
@RealizingElements
S[0:?]Reference to the connection relationship with realizing element. The relationship, if provided, assigns this element as the realizing element to the connection, which provides the physical manifestation of the connection relationship. X
ProvidesBoundariesIfcRelSpaceBoundary
@RelatedBuildingElement
S[0:?]Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces. X
ConnectedFromIfcRelConnectsElements
@RelatedElement
S[0:?]Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element. X
ContainedInStructureIfcRelContainedInSpatialStructure
@RelatedElements
S[0:1]Containment relationship to the spatial structure element, to which the element is primarily associated. This containment relationship has to be hierachical, i.e. an element may only be assigned directly to zero or one spatial structure. X
HasCoveringsIfcRelCoversBldgElements
@RelatingBuildingElement
S[0:?]Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElement. It defines the concept of an element having coverings associated.X
IfcBuildingElement
IfcBuildingElementProxy
9PredefinedTypeIfcBuildingElementProxyTypeEnum? Predefined generic type for a building element proxy that is specified in an enumeration. There may be a property set given specificly for the predefined types.
NOTE  The PredefinedType shall only be used, if no IfcBuildingElementProxyType is assigned, providing its own IfcBuildingElementProxyType.PredefinedType.
IFC4 CHANGE  The attribute CompositionType has been replaced by PredefinedType, being a superset of the enumerators.
X
Definitions applying to General Usage

 Instance diagram


Concept usage

Object Typing

The Object Typing concept template applies to this entity as shown in Table 104.

HasTypeRelatingType
IfcBuildingElementProxyType

Table 104 — IfcBuildingElementProxy Object Typing

NOTE  The IfcBuildingElementProxyType can be used to share common information among many occurrences of the same proxy without establishing a particular semantic meaning of the type.

If no IfcBuildingElementProxyType is attached (i.e. if only occurrence information is available) the PredefinedType should be provided. If set to .USERDEFINED. a user defined value has to be provided by the ObjectType attribute.



Property Sets for Objects

The Property Sets for Objects concept template applies to this entity as shown in Table 105.

PsetNameProperties
Pset_BuildingElementProxyCommon
TemplatePropertyNameValueReference
Single ValueReferenceIfcIdentifier
Single ValueIsExternalIfcBoolean
Single ValueThermalTransmittanceIfcThermalTransmittanceMeasure
Single ValueLoadBearingIfcBoolean
Single ValueFireRatingIfcLabel
Enumerated ValueStatusIfcLabel
Pset_ConcreteElementGeneral
TemplatePropertyNameValue
Single ValueConstructionMethodIfcLabel
Single ValueStructuralClassIfcLabel
Single ValueStrengthClassIfcLabel
Single ValueExposureClassIfcLabel
Single ValueReinforcementVolumeRatioIfcMassDensityMeasure
Single ValueReinforcementAreaRatioIfcAreaDensityMeasure
Single ValueDimensionalAccuracyClassIfcLabel
Single ValueConstructionToleranceClassIfcLabel
Single ValueConcreteCoverIfcPositiveLengthMeasure
Single ValueConcreteCoverAtMainBarsIfcPositiveLengthMeasure
Single ValueConcreteCoverAtLinksIfcPositiveLengthMeasure
Single ValueReinforcementStrengthClassIfcLabel
Pset_PrecastConcreteElementFabrication
TemplatePropertyNameValue
Single ValueTypeDesignatorIfcLabel
Single ValueProductionLotIdIfcIdentifier
Single ValueSerialNumberIfcIdentifier
Single ValuePieceMarkIfcLabel
Single ValueAsBuiltLocationNumberIfcLabel
Single ValueActualProductionDateIfcDateTime
Single ValueActualErectionDateIfcDateTime
Pset_PrecastConcreteElementGeneral
TemplatePropertyNameValue
Single ValueTypeDesignatorIfcLabel
Single ValueCornerChamferIfcPositiveLengthMeasure
Single ValueManufacturingToleranceClassIfcLabel
Single ValueFormStrippingStrengthIfcPressureMeasure
Single ValueLiftingStrengthIfcPressureMeasure
Single ValueReleaseStrengthIfcPressureMeasure
Single ValueMinimumAllowableSupportLengthIfcPositiveLengthMeasure
Single ValueInitialTensionIfcPressureMeasure
Single ValueTendonRelaxationIfcPositiveRatioMeasure
Single ValueTransportationStrengthIfcPressureMeasure
Single ValueSupportDuringTransportDescriptionIfcText
Single ValueHollowCorePluggingIfcLabel
Single ValueCamberAtMidspanIfcRatioMeasure
Single ValueBatterAtStartIfcPlaneAngleMeasure
Single ValueBatterAtEndIfcPlaneAngleMeasure
Single ValueTwistingIfcPlaneAngleMeasure
Single ValueShorteningIfcRatioMeasure
Single ValuePieceMarkIfcLabel
Single ValueDesignLocationNumberIfcLabel

Table 105 — IfcBuildingElementProxy Property Sets for Objects



Material Solid

The Material Single concept applies to this entity.

The material of the IfcBuildingElementProxy is defined by IfcMaterial and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship.

NOTE  It is illegal to assign an IfcMaterial to an IfcBuildingElementProxy with the PredefinedType = ProvisionForVoid.

Material information can also be given at the IfcBuildingElementProxyType, defining the common attribute data for all occurrences of the same type. It is then accessible by the inverse IsTypedBy relationship pointing to IfcBuildingElementProxyType.HasAssociations and via IfcRelAssociatesMaterial.RelatingMaterial to IfcMaterial. If both are given, then the material directly assigned to IfcBuildingElementProxy overrides the material assigned to IfcBuildingElementProxyType.



Spatial Containment

The Spatial Containment concept template applies to this entity as shown in Table 106.

RelatingStructureDescription
IfcBuildingStoreyDefault spatial container
IfcBuildingSpatial container for the element if it cannot be assigned to a building storey
IfcSiteSpatial container for the element in case that it is placed on site (outside of building)

Table 106 — IfcBuildingElementProxy Spatial Containment

The IfcBuildingElementProxy, as any subtype of IfcBuildingElement, may participate alternatively in one of the two different containment relationships:



mvdXML Specification
<?xml version="1.0"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="19a7525c-1462-4a18-b8fd-6f49a3989791" name="IfcBuildingElementProxy" status="sample" applicableRootEntity="IfcBuildingElementProxy">
  <Applicability uuid="00000000-0000-0000-0000-000000000000" status="sample">
    <Template ref="41a9fa82-bb37-4792-9f8e-fb204f74cea7" />
    <TemplateRules operator="and" />
  </Applicability>
  <Concepts>
    <Concept uuid="fe9b9377-4bd2-4585-80aa-8cddcba12af8" name="Object Typing" status="sample" override="false">
      <Template ref="35a2e10e-20df-40f4-ab2f-dacf0a6744f4" />
      <TemplateRules operator="and">
        <TemplateRule Parameters="RelatingType[Type]='IfcBuildingElementProxyType'" />
      </TemplateRules>
    </Concept>
    <Concept uuid="6d18eaa9-6256-4670-8b9c-22e468a02c6c" name="Property Sets for Objects" status="sample" override="false">
      <Template ref="f74255a6-0c0e-4f31-84ad-24981db62461" />
      <TemplateRules operator="and">
        <TemplateRule Parameters="PsetName[Value]='Pset_BuildingElementProxyCommon'" />
        <TemplateRule Parameters="PsetName[Value]='Pset_ConcreteElementGeneral'" />
        <TemplateRule Parameters="PsetName[Value]='Pset_PrecastConcreteElementFabrication'" />
        <TemplateRule Parameters="PsetName[Value]='Pset_PrecastConcreteElementGeneral'" />
      </TemplateRules>
    </Concept>
    <Concept uuid="63c37f26-a9ff-4f73-a96d-6c72d4487d50" name="Material Solid" status="sample" override="false">
      <Template ref="5f39a814-44a0-4fb3-8dc6-ddaa0560fc54" />
    </Concept>
    <Concept uuid="da51aca3-04a8-4413-9a1e-58ca10e03f83" name="Spatial Containment" status="sample" override="false">
      <Template ref="d9a3f822-0014-4bc2-8d94-9d9067759045" />
      <TemplateRules operator="and">
        <TemplateRule Description="Default spatial container " Parameters="RelatingStructure[Type]='IfcBuildingStorey'" />
        <TemplateRule Description="Spatial container for the element if it cannot be assigned to a building storey" Parameters="RelatingStructure[Type]='IfcBuilding'" />
        <TemplateRule Description="Spatial container for the element in case that it is placed on site (outside of building)" Parameters="RelatingStructure[Type]='IfcSite'" />
      </TemplateRules>
    </Concept>
  </Concepts>
</ConceptRoot>
Concept inheritance

#ConceptTemplateModel View
IfcRoot
IdentitySoftware IdentityGeneral Usage
Revision ControlRevision ControlGeneral Usage
IfcObjectDefinition
Classification AssociationClassification AssociationGeneral Usage
IfcObject
Object User IdentityObject User IdentityGeneral Usage
Object Predefined TypeObject Predefined TypeGeneral Usage
Property Sets with OverrideProperty Sets with OverrideGeneral Usage
IfcProduct
Product PlacementProduct PlacementGeneral Usage
Product Geometric RepresentationProduct Geometric RepresentationGeneral Usage
IfcElement
Product Local PlacementProduct Local PlacementGeneral Usage
CoG GeometryCoG GeometryGeneral Usage
Box GeometryBox GeometryGeneral Usage
FootPrint GeometryFootPrint GeometryGeneral Usage
Body SurfaceOrSolidModel GeometryBody SurfaceOrSolidModel GeometryGeneral Usage
Body SurfaceModel GeometryBody SurfaceModel GeometryGeneral Usage
Body Tessellation GeometryBody Tessellation GeometryGeneral Usage
Body Brep GeometryBody Brep GeometryGeneral Usage
Body AdvancedBrep GeometryBody AdvancedBrep GeometryGeneral Usage
Body CSG GeometryBody CSG GeometryGeneral Usage
Mapped GeometryMapped GeometryGeneral Usage
Element VoidingElement VoidingGeneral Usage
Element ProjectingElement ProjectingGeneral Usage
Linear PlacementProduct Linear PlacementGeneral Usage
IfcBuildingElement
Product AssignmentProduct AssignmentGeneral Usage
Surface 3D GeometrySurface 3D GeometryGeneral Usage
IfcBuildingElementProxy
Object TypingObject TypingGeneral Usage
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
Material SolidMaterial SingleGeneral Usage
Spatial ContainmentSpatial ContainmentGeneral Usage
Examples
Formal representations
XML Specification
 <xs:element name="IfcBuildingElementProxy" type="ifc:IfcBuildingElementProxy" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
 <xs:complexType name="IfcBuildingElementProxy">
  <xs:complexContent>
   <xs:extension base="ifc:IfcBuildingElement">
    <xs:attribute name="PredefinedType" type="ifc:IfcBuildingElementProxyTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcBuildingElementProxy
 SUBTYPE OF (IfcBuildingElement);
  PredefinedType : OPTIONAL IfcBuildingElementProxyTypeEnum;
 WHERE
  HasObjectName : EXISTS(SELF\IfcRoot.Name);
  CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcBuildingElementProxyTypeEnum.USERDEFINED) OR
((PredefinedType = IfcBuildingElementProxyTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
  CorrectTypeAssigned : (SIZEOF(IsTypedBy) = 0) OR
('IFCSHAREDBLDGELEMENTS.IfcBuildingElementProxyType' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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