IfcCurtainWall

Natural language names
Vorhangfassade
Curtain Wall
Mur rideau
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4 4.0.0.0
    IfcCurtainWall
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      PredefinedTypeADDED
IFC4x2 Candidate 4.2.0.0
    IfcCurtainWall
      PositionedRelativeToADDED
IFC4x3_RC3 to IFC4x3_RC4
    IfcCurtainWall
      HasSurfaceFeaturesADDED
Semantic definitions at the entity
Entity definition

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 IfcBuildingElement that uses an IfcRelAggregates relationship.

NOTE  Definition according to ISO 6707-1: non load bearing wall positioned on the outside of a building and enclosing it.

HISTORY  New entity in IFC2.0

The geometric representation of IfcCurtainWall is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Independent 'Body' geometric representation, as described below, should only be used when the IfcCurtainWall 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.

The geometric representation of IfcCurtainWall is defined using the following multiple shape representations for its definition:

Attribute definitions
#AttributeTypeCardinalityDescription G
9PredefinedTypeIfcCurtainWallTypeEnum? Predefined generic type for a curtain wall 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 IfcCurtainWallType is assigned, providing its own IfcCurtainWallType.PredefinedType.
IFC4 CHANGE The attribute has been added at the end of the entity definition.
X
Formal Propositions
RuleDescription
CorrectPredefinedTypeEither the PredefinedType attribute is unset (e.g. because an IfcCurtainWallType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
CorrectTypeAssignedEither there is no curtain wall type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcCurtainWallType.
Inherited definitions from supertypes
Entity inheritance IfcBuiltElement 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:?]X
ReferencedInStructuresIfcRelReferencedInSpatialStructure
@RelatedElements
S[0:?]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
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
HasSurfaceFeaturesIfcRelAdheresToElement
@RelatingElement
S[0:?]Reference to the IfcRelAdheresToElement relationship that adheres a IfcSurfaceFeature to an element. An element can incorporate zero-to-many surface features in one relationship. X
IfcBuiltElement
IfcCurtainWall
9PredefinedTypeIfcCurtainWallTypeEnum? Predefined generic type for a curtain wall 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 IfcCurtainWallType is assigned, providing its own IfcCurtainWallType.PredefinedType.
IFC4 CHANGE The attribute has been added at the end of the entity definition.
X
Definitions applying to General Usage

 Instance diagram


IfcCurtainWall
Concept usage

Object Typing

The Object Typing concept template applies to this entity as shown in Table 181.

HasTypeRelatingType
IfcCurtainWallType

Table 181 — IfcCurtainWall Object Typing



Property Sets for Objects

The Property Sets for Objects concept template applies to this entity as shown in Table 182.

PsetNameProperties
Pset_CurtainWallCommon
TemplatePropertyNameValueReference
Single ValueReferenceIfcIdentifier
Single ValueAcousticRatingIfcLabel
Single ValueFireRatingIfcLabel
Single ValueCombustibleIfcBoolean
Single ValueSurfaceSpreadOfFlameIfcLabel
Single ValueThermalTransmittanceIfcThermalTransmittanceMeasure
Single ValueIsExternalIfcBoolean
Enumerated ValueStatusIfcLabel

Table 182 — IfcCurtainWall Property Sets for Objects



Quantity Sets

The Quantity Sets concept template applies to this entity as shown in Table 183.

QsetNameQuantities
Qto_CurtainWallQuantities

Table 183 — IfcCurtainWall Quantity Sets



Spatial Containment

The Spatial Containment concept template applies to this entity as shown in Table 184.

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

Table 184 — IfcCurtainWall Spatial Containment



Placement

The Product Local Placement concept template applies to this entity as shown in Table 185.

Table 185 — IfcCurtainWall Product Local Placement

The following restriction may be imposed by view definitions or implementer agreements:



Axis 2D Geometry

The Axis 2D Geometry concept applies to this entity.

The following additional constraints apply to the 'Axis' representation:



mvdXML Specification
<?xml version="1.0" encoding="utf-8"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" uuid="a2b0737e-1ff6-4723-b6c3-301cdd2ba38a" name="IfcCurtainWall" applicableRootEntity="IfcCurtainWall">
 <Applicability>
  <Template ref="6eaad21b-bac5-405e-9a2c-bcdc7f76a4f4" />
  <TemplateRules operator="and">
  </TemplateRules>
 </Applicability>
 <Concepts>
  <Concept uuid="ce2087fb-2aa3-467e-9cef-2eb8bd84f7b6" name="Object Typing">
   <Template ref="35a2e10e-20df-40f4-ab2f-dacf0a6744f4" />
   <TemplateRules operator="and">
    <TemplateRule Parameters="RelatingType[Type]=&apos;IfcCurtainWallType&apos;" />
   </TemplateRules>
  </Concept>
  <Concept uuid="b5ba858c-5aff-4329-99ba-98f88f4b4e03" name="Property Sets for Objects">
   <Template ref="f74255a6-0c0e-4f31-84ad-24981db62461" />
   <TemplateRules operator="and">
    <TemplateRule Parameters="PsetName[Value]=&apos;Pset_CurtainWallCommon&apos;" />
   </TemplateRules>
  </Concept>
  <Concept uuid="f5b84420-dccb-4951-ad5e-45a41a7a6a92" name="Quantity Sets">
   <Template ref="6652398e-6579-4460-8cb4-26295acfacc7" />
   <TemplateRules operator="and">
    <TemplateRule Parameters="QsetName[Value]=&apos;Qto_CurtainWallQuantities&apos;" />
   </TemplateRules>
  </Concept>
  <Concept uuid="7cbd5f96-fbd4-46ac-9544-0a0a00366214" name="Spatial Containment">
   <Template ref="d9a3f822-0014-4bc2-8d94-9d9067759045" />
   <TemplateRules operator="and">
    <TemplateRule Description="Default spatial container" Parameters="RelatingStructure[Type]=&apos;IfcBuildingStorey&apos;" />
    <TemplateRule Description="Spatial container for the element if it cannot be assigned to a building storey - curtain wall facades may be assigned directly to the building" Parameters="RelatingStructure[Type]=&apos;IfcBuilding&apos;" />
    <TemplateRule Description="Spatial container for the element in case that it is placed on site (outside of building)" Parameters="RelatingStructure[Type]=&apos;IfcSite&apos;" />
   </TemplateRules>
  </Concept>
  <Concept uuid="a0eae462-6143-4ff3-b911-fa81421ee96c" name="Placement">
   <Template ref="cbe85b5f-7912-4a43-8bb7-1e63bf40b26d" />
  </Concept>
  <Concept uuid="05ce60f3-e203-4c86-9eb3-ae9dba04e770" name="Axis 2D Geometry">
   <Template ref="782444e8-d681-475a-9034-a9e7f53c6d65" />
  </Concept>
 </Concepts>
</ConceptRoot>
Concept inheritance

#ConceptTemplateModel View
IfcRoot
IdentitySoftware IdentityGeneral Usage
Revision ControlRevision ControlGeneral Usage
IfcObjectDefinition
Classification AssociationClassification AssociationGeneral Usage
Assignment to ProductAssignment to ProductGeneral 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
Relative PositionProduct Relative PositioningGeneral Usage
Product Span PositioningProduct Span PositioningGeneral Usage
Product Geometry ColourProduct Geometry ColourGeneral Usage
Product Geometry LayerProduct Geometry LayerGeneral Usage
Product Relative PlacementProduct Relative PlacementGeneral Usage
IfcElement
Element InterferenceElement InterferenceGeneral 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 OpeningsElement OpeningsGeneral Usage
Element ProjectingElement ProjectingGeneral Usage
Linear PlacementProduct Linear PlacementGeneral Usage
Element Voiding FeaturesElement Voiding FeaturesGeneral Usage
Surface Feature AdherenceSurface Feature AdherenceGeneral Usage
Body AdvancedSwept Directrix GeometryBody AdvancedSwept Directrix GeometryGeneral Usage
Body AdvancedSwept DiskSolid PolyCurve GeometryBody AdvancedSwept DiskSolid PolyCurve GeometryGeneral Usage
Body AdvancedSwept Tapered GeometryBody AdvancedSwept Tapered GeometryGeneral Usage
Body SectionedSolidHorizontalBody SectionedSolidHorizontalGeneral Usage
Body SweptSolid Composite GeometryBody SweptSolid Composite GeometryGeneral Usage
Body SweptSolid ParameterizedProfile GeometryBody SweptSolid ParameterizedProfile GeometryGeneral Usage
Body SweptSolid CompositeCurve GeometryBody SweptSolid CompositeCurve GeometryGeneral Usage
Body SweptSolid PolyCurve GeometryBody SweptSolid PolyCurve GeometryGeneral Usage
FootPrint Annotation GeometryFootPrint Annotation GeometryGeneral Usage
FootPrint GeomSet PolyCurve GeometryFootPrint GeomSet PolyCurve GeometryGeneral Usage
Surface Sectioned GeometrySurface Sectioned GeometryGeneral Usage
Surface Tessellation GeometrySurface Tessellation GeometryGeneral Usage
Product Grid PlacementProduct Grid PlacementGeneral Usage
IfcBuiltElement
Product AssignmentProduct AssignmentGeneral Usage
Surface 3D GeometrySurface 3D GeometryGeneral Usage
Material SetMaterial SetGeneral Usage
IfcCurtainWall
Object TypingObject TypingGeneral Usage
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
Quantity SetsQuantity SetsGeneral Usage
Spatial ContainmentSpatial ContainmentGeneral Usage
PlacementProduct Local PlacementGeneral Usage
Axis 2D GeometryAxis 2D GeometryGeneral Usage
Formal representations
XML Specification
 <xs:element name="IfcCurtainWall" type="ifc:IfcCurtainWall" substitutionGroup="ifc:IfcBuiltElement" nillable="true"/>
 <xs:complexType name="IfcCurtainWall">
  <xs:complexContent>
   <xs:extension base="ifc:IfcBuiltElement">
    <xs:attribute name="PredefinedType" type="ifc:IfcCurtainWallTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcCurtainWall
 SUBTYPE OF (IfcBuiltElement);
  PredefinedType : OPTIONAL IfcCurtainWallTypeEnum;
 WHERE
  CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcCurtainWallTypeEnum.USERDEFINED) OR
((PredefinedType = IfcCurtainWallTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
  CorrectTypeAssigned : (SIZEOF(IsTypedBy) = 0) OR
('IFCSHAREDBLDGELEMENTS.IfcCurtainWallType' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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