IfcCurtainWall

Natural language names
deVorhangfassade
enCurtain Wall
frMur rideau
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcCurtainWall
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      PredefinedTypeADDED
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 C
9PredefinedTypeIfcCurtainWallTypeEnum[0:1] 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.
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 IfcBuildingElement IfcElement IfcProduct IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcRoot
1GlobalIdIfcGloballyUniqueId[1:1] Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory[0:1] 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.
X
3NameIfcLabel[0:1] 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[0:1] 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). 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). 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. 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). 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). 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[0:1] 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. 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. 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. 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. X
IfcProduct
6ObjectPlacementIfcObjectPlacement[0:1] 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[0:1] 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
IfcElement
8TagIfcIdentifier[0:1] 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.
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.
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. 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
IfcCurtainWall
9PredefinedTypeIfcCurtainWallTypeEnum[0:1] 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.
X
Definitions applying to Common Use Definitions

 Instance diagram


Concept usage

Object Typing

The Object Typing concept applies to this entity as shown in Table 114.

Type
IfcCurtainWallType

Table 114 — IfcCurtainWall Object Typing



Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 115.

PredefinedTypeNameProperties
 Pset_CurtainWallCommonSingle Value
NameValue
ReferenceIfcIdentifier
AcousticRatingIfcLabel
FireRatingIfcLabel
CombustibleIfcBoolean
SurfaceSpreadOfFlameIfcLabel
ThermalTransmittanceIfcThermalTransmittanceMeasure
IsExternalIfcBoolean
Enumerated Value
NameValueValue
StatusIfcLabelIfcLabel
 Pset_EnvironmentalImpactIndicatorsSingle Value
NameValue
ReferenceIfcIdentifier
FunctionalUnitReferenceIfcLabel
UnitIfcText
ExpectedServiceLifeIfcTimeMeasure
TotalPrimaryEnergyConsumptionPerUnitIfcEnergyMeasure
WaterConsumptionPerUnitIfcVolumeMeasure
HazardousWastePerUnitIfcMassMeasure
NonHazardousWastePerUnitIfcMassMeasure
ClimateChangePerUnitIfcMassMeasure
AtmosphericAcidificationPerUnitIfcMassMeasure
RenewableEnergyConsumptionPerUnitIfcEnergyMeasure
NonRenewableEnergyConsumptionPerUnitIfcEnergyMeasure
ResourceDepletionPerUnitIfcMassMeasure
InertWastePerUnitIfcMassMeasure
RadioactiveWastePerUnitIfcMassMeasure
StratosphericOzoneLayerDestructionPerUnitIfcMassMeasure
PhotochemicalOzoneFormationPerUnitIfcMassMeasure
EutrophicationPerUnitIfcMassMeasure
Enumerated Value
NameValueValue
LifeCyclePhaseIfcLabelIfcLabel
 Pset_EnvironmentalImpactValuesSingle Value
NameValue
TotalPrimaryEnergyConsumptionIfcEnergyMeasure
WaterConsumptionIfcVolumeMeasure
HazardousWasteIfcMassMeasure
NonHazardousWasteIfcMassMeasure
ClimateChangeIfcMassMeasure
AtmosphericAcidificationIfcMassMeasure
RenewableEnergyConsumptionIfcEnergyMeasure
NonRenewableEnergyConsumptionIfcEnergyMeasure
ResourceDepletionIfcMassMeasure
InertWasteIfcMassMeasure
RadioactiveWasteIfcMassMeasure
StratosphericOzoneLayerDestructionIfcMassMeasure
PhotochemicalOzoneFormationIfcMassMeasure
EutrophicationIfcMassMeasure
LeadInTimeIfcDuration
DurationIfcDuration
LeadOutTime 
 Pset_ConditionSingle Value
NameValue
AssessmentDateIfcDate
AssessmentConditionIfcLabel
AssessmentDescriptionIfcText
 Pset_ManufacturerOccurrenceSingle Value
NameValue
AcquisitionDateIfcDate
BarCodeIfcIdentifier
SerialNumberIfcIdentifier
BatchReferenceIfcIdentifier
Enumerated Value
NameValueValue
AssemblyPlaceIfcLabelIfcLabel
 Pset_ManufacturerTypeInformationSingle Value
NameValue
GlobalTradeItemNumberIfcIdentifier
ArticleNumberIfcIdentifier
ModelReferenceIfcLabel
ModelLabelIfcLabel
ManufacturerIfcLabel
ProductionYearIfcLabel
Enumerated Value
NameValueValue
AssemblyPlaceIfcLabelIfcLabel
 Pset_ServiceLifeSingle Value
NameValue
MeanTimeBetweenFailureIfcDuration
Bounded Value
NameValueValue
ServiceLifeDurationIfcDurationIfcDuration
 Pset_WarrantySingle Value
NameValue
WarrantyIdentifierIfcIdentifier
WarrantyStartDateIfcDate
WarrantyEndDateIfcDate
IsExtendedWarrantyIfcBoolean
WarrantyPeriodIfcTimeMeasure
WarrantyContentIfcText
ExclusionsIfcText

Table 115 — IfcCurtainWall Property Sets for Objects



Quantity Sets

The Quantity Sets concept applies to this entity as shown in Table 116.

Name
Qto_CurtainWallQuantities

Table 116 — IfcCurtainWall Quantity Sets



Spatial Containment

The Spatial Containment concept applies to this entity as shown in Table 117.

StructureDescription
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 117 — IfcCurtainWall Spatial Containment



Product Local Placement

The Product Local Placement concept applies to this entity as shown in Table 118.

TypeRelativeDescription
IfcLocalPlacementIfcLocalPlacementRelative placement according to position and rotation relative to container.
IfcLocalPlacementAbsolute placement according to position and rotation of world coordinate system.
IfcGridPlacementPlacement according to grid intersection.

Table 118 — IfcCurtainWall Product Local Placement

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

  • If the IfcCurtainWall establishes an aggregate, then all contained elements shall be placed relative to the IfcCurtainWall.ObjectPlacement.


Axis 2D Geometry

The Axis 2D Geometry concept applies to this entity.

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



Concept inheritance

#ConceptModel View
IfcRoot
Software IdentityCommon Use Definitions
Revision ControlCommon Use Definitions
IfcObject
Object Occurrence Predefined TypeCommon Use Definitions
IfcElement
Box GeometryCommon Use Definitions
FootPrint GeometryCommon Use Definitions
Body SurfaceOrSolidModel GeometryCommon Use Definitions
Body SurfaceModel GeometryCommon Use Definitions
Body Tessellation GeometryCommon Use Definitions
Body Brep GeometryCommon Use Definitions
Body AdvancedBrep GeometryCommon Use Definitions
Body CSG GeometryCommon Use Definitions
Mapped GeometryCommon Use Definitions
Mesh GeometryCommon Use Definitions
IfcBuildingElement
Product AssignmentCommon Use Definitions
Surface 3D GeometryCommon Use Definitions
IfcCurtainWall
Object TypingCommon Use Definitions
Property Sets for ObjectsCommon Use Definitions
Quantity SetsCommon Use Definitions
Spatial ContainmentCommon Use Definitions
Product Local PlacementCommon Use Definitions
Axis 2D GeometryCommon Use Definitions
Formal representations
XSD Specification
 <xs:element name="IfcCurtainWall" type="ifc:IfcCurtainWall" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
 <xs:complexType name="IfcCurtainWall">
  <xs:complexContent>
   <xs:extension base="ifc:IfcBuildingElement">
    <xs:attribute name="PredefinedType" type="ifc:IfcCurtainWallTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcCurtainWall
 SUBTYPE OF (IfcBuildingElement);
  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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