6.1.3.41 IfcWall

6.1.3.41.1 Semantic definition

The wall represents a vertical construction that may bound or subdivide 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.

A wall may have openings, such as wall openings, openings used for windows or doors, or niches and recesses. They are defined by an IfcOpeningElement attached to the wall using the inverse relationship HasOpenings pointing to IfcRelVoidsElement. Walls with openings that have already been modeled within the enclosing geometry may use the relationship IfcRelConnectsElements to associate the wall with embedded elements such as doors and windows.

There are two main representations for all occurrences:

IfcWall with IfcMaterialLayerSetUsage is 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.
IfcWall without IfcMaterialLayerSetUsage is 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, or if a more parametric representation is not intended.

6.1.3.41.2 Entity inheritance

6.1.3.41.3 Attributes

#	Attribute	Type	Description
IfcRoot (4)
1	GlobalId	IfcGloballyUniqueId	Assignment of a globally unique identifier within the entire software world.
2	OwnerHistory	OPTIONAL IfcOwnerHistory	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 is stored - either as addition, deletion or modification. IFC4-CHANGE The attribute has been changed to be OPTIONAL.
3	Name	OPTIONAL IfcLabel	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.
4	Description	OPTIONAL IfcText	Optional description, provided for exchanging informative comments.
IfcObjectDefinition (7)
	HasAssignments	SET [0:?] OF IfcRelAssigns FOR RelatedObjects	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.
	Nests	SET [0:1] OF IfcRelNests FOR RelatedObjects	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 structures only). IFC4-CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
	IsNestedBy	SET [0:?] OF IfcRelNests FOR RelatingObject	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.
	HasContext	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions	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.
	IsDecomposedBy	SET [0:?] OF IfcRelAggregates FOR RelatingObject	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 definition 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.
	Decomposes	SET [0:1] OF IfcRelAggregates FOR RelatedObjects	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 definition can only be part of a single decomposition (to allow hierarchical structures only). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	HasAssociations	SET [0:?] OF IfcRelAssociates FOR RelatedObjects	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.
IfcObject (5)
5	ObjectType	OPTIONAL IfcLabel	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 or when the concrete entity instantiated does not have a PredefinedType attribute. The latter is the case in some exceptional leaf classes and when instantiating IfcBuiltElement directly.
	IsDeclaredBy	SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects	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.
	Declares	SET [0:?] OF IfcRelDefinesByObject FOR RelatingObject	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.
	IsTypedBy	SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects	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 was previously included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
	IsDefinedBy	SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjects	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.
IfcProduct (5)
6	ObjectPlacement	OPTIONAL IfcObjectPlacement	This establishes the object coordinate system and 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 constrained (e.g. relative to grid axes, or to a linear positioning element). The type of placement is determined by the various subtypes of IfcObjectPlacement. An object placement must be provided if a representation is present.
7	Representation	OPTIONAL IfcProductRepresentation	Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case of a shape representation (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.
	ReferencedBy	SET [0:?] OF IfcRelAssignsToProduct FOR RelatingProduct	Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.
	PositionedRelativeTo	SET [0:?] OF IfcRelPositions FOR RelatedProducts	Reference to the IfcRelPositions relationship, which defines its relationship with a positioning element.
	ReferencedInStructures	SET [0:?] OF IfcRelReferencedInSpatialStructure FOR RelatedElements	Reference to the objectified relationship IfcRelReferencedInSpatialStructure may be used to relate a product to one or more spatial structure elements in addition to the one in which it is primarily contained.
IfcElement (13)
8	Tag	OPTIONAL IfcIdentifier	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.
	FillsVoids	SET [0:1] OF IfcRelFillsElement FOR RelatedBuildingElement	Reference to the IfcRelFillsElement relationship that puts the element as a filling into the opening created within another element.
	ConnectedTo	SET [0:?] OF IfcRelConnectsElements FOR RelatingElement	Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to.
	IsInterferedByElements	SET [0:?] OF IfcRelInterferesElements FOR RelatedElement	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.
	InterferesElements	SET [0:?] OF IfcRelInterferesElements FOR RelatingElement	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.
	HasProjections	SET [0:?] OF IfcRelProjectsElement FOR RelatingElement	Projection relationship that adds a feature (using a Boolean union) to the IfcBuiltElement.
	HasOpenings	SET [0:?] OF IfcRelVoidsElement FOR RelatingBuildingElement	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.
	IsConnectionRealization	SET [0:?] OF IfcRelConnectsWithRealizingElements FOR RealizingElements	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.
	ProvidesBoundaries	SET [0:?] OF IfcRelSpaceBoundary FOR RelatedBuildingElement	Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces.
	ConnectedFrom	SET [0:?] OF IfcRelConnectsElements FOR RelatedElement	Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element.
	ContainedInStructure	SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements	Containment relationship to the spatial structure element, to which the element is primarily associated. This containment relationship has to be hierarchical, i.e. an element may only be assigned directly to zero or one spatial structure.
	HasCoverings	SET [0:?] OF IfcRelCoversBldgElements FOR RelatingBuildingElement	Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElements. It defines the concept of an element having coverings associated.
	HasSurfaceFeatures	SET [0:?] OF IfcRelAdheresToElement FOR RelatingElement	Reference to the IfcRelAdheresToElement relationship that adheres a IfcSurfaceFeature to an element. An element can incorporate zero-to-many surface features in one relationship.
Click to show 34 hidden inherited attributes
IfcWall (1)
9	PredefinedType	OPTIONAL IfcWallTypeEnum	Predefined generic type for a wall that is specified in an enumeration. There may be a property set given specifically for the predefined types. NOTE The PredefinedType shall only be used, if no IfcWallType is assigned, providing its own IfcWallType.PredefinedType. IFC4-CHANGE The attribute has been added at the end of the entity definition.

Table 6.1.3.41.P

6.1.3.41.4 Formal propositions

Name Description

CorrectPredefinedType

Either the PredefinedType attribute is unset (e.g. because an IfcWallType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.

 NOT(EXISTS(PredefinedType)) OR
 (PredefinedType <> IfcWallTypeEnum.USERDEFINED) OR
 ((PredefinedType = IfcWallTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType))

CorrectTypeAssigned

Either there is no wall type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcWallType.

 (SIZEOF(IsTypedBy) = 0) OR
  ('IFC4X3_DEV_738df036.IFCWALLTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType))

Table 6.1.3.41.Q

6.1.3.41.5 Property sets

Pset_ConcreteElementGeneral
- AssemblyPlace
- CastingMethod
- StructuralClass
- StrengthClass
- ExposureClass
- ReinforcementVolumeRatio
- ReinforcementAreaRatio
- DimensionalAccuracyClass
- ConstructionToleranceClass
- ConcreteCover
- ConcreteCoverAtMainBars
- ConcreteCoverAtLinks
- ReinforcementStrengthClass
Pset_Condition
- AssessmentDate
- AssessmentCondition
- AssessmentDescription
- AssessmentType
- AssessmentMethod
- LastAssessmentReport
- NextAssessmentDate
- AssessmentFrequency
Pset_ConstructionAdministration
- ProcurementMethod
- SpecificationSectionNumber
- SubmittalIdentifer
Pset_ConstructionOccurence
- InstallationDate
- ModelNumber
- TagNumber
- AssetIdentifier
Pset_ElementKinematics
- CyclicPath
- CyclicRange
- LinearPath
- LinearRange
- MaximumAngularVelocity
- MaximumConstantSpeed
- MinimumTime
Pset_EnvironmentalCondition
- ReferenceAirRelativeHumidity
- ReferenceEnvironmentTemperature
- MaximumAtmosphericPressure
- StorageTemperatureRange
- MaximumWindSpeed
- OperationalTemperatureRange
- MaximumRainIntensity
- SaltMistLevel
- SeismicResistance
- SmokeLevel
- MaximumSolarRadiation
Pset_EnvironmentalImpactIndicators
- Reference
- FunctionalUnitReference
- IndicatorsUnit
- LifeCyclePhase
- ExpectedServiceLife
- TotalPrimaryEnergyConsumptionPerUnit
- WaterConsumptionPerUnit
- HazardousWastePerUnit
- NonHazardousWastePerUnit
- ClimateChangePerUnit
- AtmosphericAcidificationPerUnit
- RenewableEnergyConsumptionPerUnit
- NonRenewableEnergyConsumptionPerUnit
- ResourceDepletionPerUnit
- InertWastePerUnit
- RadioactiveWastePerUnit
- StratosphericOzoneLayerDestructionPerUnit
- PhotochemicalOzoneFormationPerUnit
- EutrophicationPerUnit
Pset_EnvironmentalImpactValues
- TotalPrimaryEnergyConsumption
- WaterConsumption
- HazardousWaste
- NonHazardousWaste
- ClimateChange
- AtmosphericAcidification
- RenewableEnergyConsumption
- NonRenewableEnergyConsumption
- ResourceDepletion
- InertWaste
- RadioactiveWaste
- StratosphericOzoneLayerDestruction
- PhotochemicalOzoneFormation
- Eutrophication
- LeadInTime
- Duration
- LeadOutTime
Pset_InstallationOccurrence
- InstallationDate
- AcceptanceDate
- PutIntoOperationDate
Pset_MaintenanceStrategy
- AssetCriticality
- AssetFrailty
- AssetPriority
- MonitoringType
- AccidentResponse
Pset_MaintenanceTriggerCondition
- ConditionTargetPerformance
- ConditionMaintenanceLevel
- ConditionReplacementLevel
- ConditionDisposalLevel
Pset_MaintenanceTriggerDuration
- DurationTargetPerformance
- DurationMaintenanceLevel
- DurationReplacementLevel
- DurationDisposalLevel
Pset_MaintenanceTriggerPerformance
- TargetPerformance
- PerformanceMaintenanceLevel
- ReplacementLevel
- DisposalLevel
Pset_ManufacturerOccurrence
- AcquisitionDate
- BarCode
- SerialNumber
- BatchReference
- AssemblyPlace
- ManufacturingDate
Pset_ManufacturerTypeInformation
- GlobalTradeItemNumber
- ArticleNumber
- ModelReference
- ModelLabel
- Manufacturer
- ProductionYear
- AssemblyPlace
- OperationalDocument
- SafetyDocument
- PerformanceCertificate
Pset_PrecastConcreteElementFabrication
- TypeDesignation
- ProductionLotId
- SerialNumber
- PieceMark
- AsBuiltLocationNumber
- ActualProductionDate
- ActualErectionDate
Pset_PrecastConcreteElementGeneral
- TypeDesignation
- CornerChamfer
- ManufacturingToleranceClass
- FormStrippingStrength
- LiftingStrength
- ReleaseStrength
- MinimumAllowableSupportLength
- InitialTension
- TendonRelaxation
- TransportationStrength
- SupportDuringTransportDescription
- SupportDuringTransportDocReference
- HollowCorePlugging
- CamberAtMidspan
- BatterAtStart
- BatterAtEnd
- Twisting
- Shortening
- PieceMark
- DesignLocationNumber
Pset_ReinforcementBarPitchOfWall
- Description
- Reference
- BarAllocationType
- VerticalBarPitch
- HorizontalBarPitch
- SpacingBarPitch
Pset_RepairOccurrence
- RepairContent
- RepairDate
- MeanTimeToRepair
Pset_Risk
- RiskName
- RiskType
- NatureOfRisk
- RiskAssessmentMethodology
- UnmitigatedRiskLikelihood
- UnmitigatedRiskConsequence
- UnmitigatedRiskSignificance
- MitigationPlanned
- MitigatedRiskLikelihood
- MitigatedRiskConsequence
- MitigatedRiskSignificance
- MitigationProposed
- AssociatedProduct
- AssociatedActivity
- AssociatedLocation
Pset_RoadGuardElement PARAPET
- IsMoveable
- IsTerminal
- IsTransition
- TerminalType
Pset_ServiceLife
- ServiceLifeDuration
- MeanTimeBetweenFailure
Pset_Tolerance
- ToleranceDescription
- ToleranceBasis
- OverallTolerance
- HorizontalTolerance
- OrthogonalTolerance
- VerticalTolerance
- PlanarFlatness
- HorizontalFlatness
- ElevationalFlatness
- SideFlatness
- OverallOrthogonality
- HorizontalOrthogonality
- OrthogonalOrthogonality
- VerticalOrthogonality
- OverallStraightness
- HorizontalStraightness
- OrthogonalStraightness
- VerticalStraightness
Pset_Uncertainty
- UncertaintyBasis
- UncertaintyDescription
- HorizontalUncertainty
- LinearUncertainty
- OrthogonalUncertainty
- VerticalUncertainty
Pset_WallCommon
- Reference
- Status
- AcousticRating
- FireRating
- Combustible
- SurfaceSpreadOfFlame
- ThermalTransmittance
- IsExternal
- LoadBearing
- ExtendToStructure
- Compartmentation
Pset_Warranty
- WarrantyIdentifier
- WarrantyStartDate
- IsExtendedWarranty
- WarrantyPeriod
- WarrantyContent
- PointOfContact
- Exclusions
Qto_BodyGeometryValidation
- GrossSurfaceArea
- NetSurfaceArea
- GrossVolume
- NetVolume
- SurfaceGenusBeforeFeatures
- SurfaceGenusAfterFeatures
Qto_WallBaseQuantities
- Length
- Width
- Height
- GrossFootPrintArea
- NetFootPrintArea
- GrossSideArea
- NetSideArea
- GrossVolume
- NetVolume
- GrossWeight
- NetWeight

6.1.3.41.6 Concept usage

Brep representation — Figure 6.1.3.41.A — Building element body boundary representation

surface model — Figure 6.1.3.41.A — Building element body boundary representation

Concept	Usage	Description
IfcRoot (2)
Revision Control	General	Ownership, history, and merge state is captured using IfcOwnerHistory.
Software Identity	General	IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.
IfcObjectDefinition (9)
Classification Association	General	Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.
Aggregation	General	No description available.
Approval Association	General	No description available.
Constraint Association	General	No description available.
Document Association	General	No description available.
Library Association	General	No description available.
Material Association	General	No description available.
Material Single	General	No description available.
Nesting	General	No description available.
IfcObject (5)
Object Predefined Type	General	No description available.
Object Typing	General	Any object occurrence can be typed by being assigned to a common object type utilizing this concept. A particular rule, restricting the applicable subtypes of IfcTypeObject that can be assigned, is introduced by overriding this concept at the level of subtypes of IfcObject. This concept can be applied to the following resources: IfcTypeObject
Object User Identity	General	An attribute Name and optionally Description can be used for all subypes of IfcObject. For those subtypes, that have an object type definition, such as IfcBeam - IfcBeamType, the common Name and optionally Description is associated with the object type.
Property Sets with Override	General	Any object occurrence can hold property sets, either directly at the object occurrence as element specific property sets, or at the object type, as type property sets. In this case, the properties that are provided to the object occurrence are the combinations of element specific and type properties. In case that the same property (within the same property set) is defined both in occurrence and type properties, the property value of the occurrence property overrides the property value of the type property.
Assignment to Group	General	No description available.
IfcProduct (18)
Body Geometry	General	The body or solid model geometric representation of an IfcProduct is typically defined using a Tessellation or Brep. Subtypes may provide recommendations on other representation types that may be used. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used: IfcShapeRepresentation.RepresentationIdentifier = 'Body' IfcShapeRepresentation.RepresentationType = Typically 'Tessellation' or 'Brep'
Product Geometric Representation	General	The geometric representation of any IfcProduct is provided by the IfcProductDefinitionShape allowing multiple geometric representations. It uses the Product Placement concept utilizing IfcLocalPlacement to establish an object coordinate system, in which all geometric representations are founded. NOTE A detailed specification of how to apply the local placement and which shape representations are applicable is provided at the level of subtypes of IfcProduct and is further determined by the model view definition and implementer agreements.
Product Geometry Colour	General	No description available.
Product Geometry Layer	General	No description available.
Product Relative Positioning	General	If the IfcProduct Product Placement is placed relative to an IfcPositioningElement this relationship covers the information on which IfcPositioningElement positions the IfcProduct.
Product Span Positioning	General	No description available.
Box Geometry	General	No description available.
CoG Geometry	General	No description available.
Mapped Geometry	General	No description available.
Object Typing	General	This is a further elaboration on an inherited concept. This concept can be applied to the following resources: IfcTypeProduct
Product Local Placement	General	No description available.
Product Topology Representation	General	No description available.
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_Risk Pset_Tolerance Pset_Uncertainty
Quantity Sets	General	This concept can be applied to the following resources: Qto_BodyGeometryValidation
Reference Geometry	General	No description available.
Reference SweptSolid Geometry	General	No description available.
Reference SweptSolid PolyCurve Geometry	General	No description available.
Reference Tessellation Geometry	General	No description available.
IfcElement (44)
Body AdvancedBrep Geometry	General	An IfcElement (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 models, which include advanced surfaces, usually referred to as NURBS surfaces. The 'AdvancedBrep' representation allows for the representation of complex free-form element shape. NOTE View definitions or implementer agreements may restrict or disallow the use of 'AdvancedBrep' geometry.
Body AdvancedSwept Directrix Geometry	General	No description available.
Body AdvancedSwept DiskSolid PolyCurve Geometry	General	No description available.
Body AdvancedSwept Tapered Geometry	General	No description available.
Body Brep Geometry	General	Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a single or multiple Boundary Representation models (which are restricted to be faceted Brep's with or without voids). The Brep representation allows for the representation of complex element shape. Figure 6.1.3.41.A — Building element body boundary representation EXAMPLE As shown in Figure 6.1.3.41.A, the Brep representation is given by an IfcShapeRepresentation, which includes one or more items, all of type IfcFacetedBrep. In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.
Body CSG Geometry	General	Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a CSG primitive or CSG tree. The CSG representation allows for the representation of complex element shape. NOTE View definitions or implementer agreements may restrict or disallow the use of 'CSG' geometry.
Body SectionedSolidHorizontal	General	No description available.
Body SurfaceModel Geometry	General	Any IfcElement (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 surface models. It may also include tessellated models. Figure 6.1.3.41.B — Element surface model representation EXAMPLE As shown in Figure 6.1.3.41.B, the surface model representation is given by an IfcShapeRepresentation, which includes a single item which is either an IfcShellBasedSurfaceModel, or an IfcFaceBasedSurfaceModel. In some cases it may also be useful to expose a simple representation as a bounding box representation of the same complex shape.
Body SurfaceOrSolidModel Geometry	General	Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a mixed representation, including surface and solid models.
Body SweptSolid Composite Geometry	General	No description available.
Body SweptSolid CompositeCurve Geometry	General	No description available.
Body SweptSolid ParameterizedProfile Geometry	General	No description available.
Body SweptSolid PolyCurve Geometry	General	No description available.
Body Tessellation Geometry	Reference View	Any IfcElement (so far no further constraints are defined at the level of its subtypes) may be represented as a single or multiple tessellated surface models, in particular triangulated surface models.
Box Geometry	General	This is a further elaboration on an inherited concept. Figure 6.1.3.41.C — Building element box representation EXAMPLE Any IfcElement may be represented by a bounding box, which shows the maximum extent of the body within the object coordinate system established by the IfcObjectPlacement. As shown in Figure 6.1.3.41.C, the bounding box representation is given by an IfcShapeRepresentation that includes a single item: an IfcBoundingBox.
CoG Geometry	General	This is a further elaboration on an inherited concept. The 'CoG', Center of Gravity, shape representation is used as a means to verify the correct import by comparing the CoG of the imported geometry with the explicitly provided CoG created during export.
Element Interference	General	No description available.
Element Nesting	General	A host element can nest connected components. This should be used when there is a specific position or form factor to attach specific elements. EXAMPLE A sink has a pre-drilled hole to attach a faucet.
Element Projecting	General	No description available.
Element Voiding Features	General	No description available.
FootPrint Annotation Geometry	General	No description available.
FootPrint GeomSet PolyCurve Geometry	General	No description available.
FootPrint Geometry	General	No description available.
Mapped Geometry	General	This is a further elaboration on an inherited concept. Any IfcElement (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 results are more compact data sets. The same constraints, as given for 'SurfaceOrSolidModel', 'SurfaceModel', 'Tessellation', 'Brep', and 'AdvancedBrep' geometric representation, shall apply to the IfcRepresentationMap.
Product Grid Placement	General	No description available.
Product Linear Placement	General	Product placement with a Product Linear Placement template. It defines the local coordinate system based on the curve which is referenced by IfcLinearPlacement.RelativePlacement which is an IfcAxis2PlacementLinear.Location using an IfcPointByDistanceExpression.BasisCurve. The local coordinate system is based on the tangent of the curve at Location, its normal in the global Z plane and the cross product of the aforementioned vectors.
Product Local Placement	General	This is a further elaboration on an inherited concept. The object placement for any subtype of IfcElement is defined by the IfcObjectPlacement, either IfcLocalPlacement or IfcGridPlacement, which defines the local object coordinate system that is referenced by all geometric representations of that IfcElement.
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_Condition Pset_InstallationOccurrence Pset_MaintenanceStrategy Pset_MaintenanceTriggerCondition Pset_MaintenanceTriggerDuration Pset_MaintenanceTriggerPerformance Pset_RepairOccurrence Pset_ConstructionAdministration Pset_ConstructionOccurence Pset_ElementKinematics Pset_EnvironmentalCondition Pset_EnvironmentalImpactIndicators Pset_EnvironmentalImpactValues Pset_ManufacturerOccurrence Pset_ManufacturerTypeInformation Pset_ServiceLife Pset_Warranty
Surface Feature Adherence	General	No description available.
Surface Sectioned Geometry	General	No description available.
Surface Tessellation Geometry	General	No description available.
Body AdvancedSweptSolid Geometry	General	No description available.
Body Clipping Geometry	General	No description available.
Body SweptSolid Geometry	General	No description available.
Element Covering	General	No description available.
Element Occurrence Attributes	General	No description available.
Element Voiding	General	No description available.
Lighting Geometry	General	No description available.
Object Typing	General	This concept can be applied to the following resources: IfcElementType
Profile 3D Geometry	General	No description available.
Profile Geometry	General	No description available.
Spatial Containment	General	This concept can be applied to the following resources: IfcSpatialElement
Surface 3D Geometry	General	No description available.
Surface Geometry	General	No description available.
IfcBuiltElement (3)
Product Assignment	General	This concept can be applied to the following resources: IfcTask - A task for operating on the wall.
Surface 3D Geometry	General	This is a further elaboration on an inherited concept. Some IfcBuiltElement may be represented by a surface as an abstract geometric representation. See each subtype for specific guidance.
Object Typing	General	This concept can be applied to the following resources: IfcBuiltElementType
Click to show 81 hidden inherited concepts
IfcWall (15)
Axis 2D Geometry	General	The wall axis is represented by a two-dimensional open curve within a particular shape representation. The 'Axis' shape representation is only used to locate the material layer set along the axis, if the IfcMaterialLayerSetUsage is applied to the IfcWall. In this case, the wall axis is used to apply the material layer set usage parameter to the wall geometry. Axis IfcPolyline having two Points, or IfcTrimmedCurve with BasisCurve of Type IfcLine for the 'SweptSolid' provided as IfcExtrudedAreaSolid. The axis curve lies on the x/y plane and is parallel to the x-axis of the object coordinate system. IfcTrimmedCurve with BasisCurve of Type IfcCircle for 'SweptSolid' provided as IfcExtrudedAreaSolid. The axis curve lies on the x/y plane of the object coordinate system, the tangent at the start is along the positive x-axis. Figure 6.1.3.41.D — Wall axis straight Figure 6.1.3.41.D 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 IfcPolyline or IfcTrimmedCurve with the BasisCurve being an IfcLine. The IfcPolyline or IfcTrimmedCurve 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. Figure 6.1.3.41.E — Wall axis curved Figure 6.1.3.41.E 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 IfcTrimmedCurve. The curve shall have a BasisCurve of type IfcCircle. The tangent of the IfcTrimmedCurve 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.
Body Clipping Geometry	General	This is a further elaboration on an inherited concept. The following additional constraints apply to the 'SweptSolid' representation, when an IfcMaterialLayerSetUsage is assigned to the IfcSlab: Solid: IfcExtrudedAreaSolid is required Profile: IfcArbitraryClosedProfileDef and IfcRectangleProfileDef shall be supported. Extrusion: All extrusion directions shall be supported. Boolean result: The IfcBooleanClippingResult shall be supported, allowing for Boolean differences between the swept solid (here IfcExtrudedAreaSolid) and one or several IfcHalfSpaceSolid (or subtypes). Figure 6.1.3.41.F illustrates a clipping for a straight wall using an IfcPolygonalBoundedHalfSpace as SecondOperand in the IfcBooleanClippingResult. Figure 6.1.3.41.F — Wall body clipping straight Figure 6.1.3.41.G illustrates a clipping for a curved wall using an IfcHalfSpaceSolid as SecondOperand in the IfcBooleanClippingResult. Figure 6.1.3.41.G — Wall body clipping curved
Body SweptSolid Geometry	General	This is a further elaboration on an inherited concept. The following additional constraints apply to the 'SweptSolid' representation: Solid: IfcExtrudedAreaSolid is required Profile: IfcArbitraryClosedProfileDef and IfcRectangleProfileDef shall be supported. Extrusion: All extrusion directions shall be supported. Additional constraints apply to the 'SweptSolid' representation, when an IfcMaterialLayerSetUsage is used: Extrusion: The profile shall be extruded vertically, i.e., in the direction of the z-axis of the coordinate 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 IfcExtrudedAreaSolid. 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 IfcArbitraryClosedProfileDef (excluding its subtypes). The profile is given with all wall connections already resolved. Figure 6.1.3.41.H 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. Figure 6.1.3.41.H — Wall body extrusion straight Figure 6.1.3.41.I 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. Figure 6.1.3.41.I — Wall body extrusion curved
Element Decomposition	General	A wall may decomposed into parts such as framing and panels on each side. For efficiency, each part may reuse geometry using the mapped geometry concept. Figure 6.1.3.41.J — A wall decomposed into parts. This concept can be applied to the following resources: IfcMember - Studs, posts and similar elements IfcMechanicalFastener - Fasteners that may be used to connect elements together with IfcRelConnectsWithRealizingElements IfcElementAssembly - Frame containing studs, tracks, and possibly insulation IfcBuildingElementPart - Panels on each side such as gypsum (drywall) or cement board (tile backing) with fasteners
Element Voiding	General	This is a further elaboration on an inherited concept. As shown in Figure 6.1.3.41.K, openings within the composite wall are directly assigned to IfcWall using IfcRelVoidsElement pointing to IfcOpeningElement and apply to all aggregated parts. If individual parts have cutting and other voiding features, then the decomposed parts have a separate voiding relationship IfcRelVoidsElement pointing to IfcVoidingFeature. Figure 6.1.3.41.K — How individual parts being cut may be expressed.
Material Layer Set Usage	General	Figure 6.1.3.41.L illustrates assignment of IfcMaterialLayerSetUsage and IfcMaterialLayerSet to the IfcWallType and the IfcWall occurrence. Figure 6.1.3.41.L — Wall Standard Object Typing Figure 6.1.3.41.M illustrates material layer usage, where: The reference coordinate system is the local coordinate system established by the ObjectPlacement of the IfcWall. The reference axis is the axis defined by the IfcShapeRepresentation with RepresentationType='Axis' as one of the wall's representations. The IfcMaterialLayerSetUsage.OffsetFromReferenceLine is given as a distance from this axis. The IfcMaterialLayerSetUsage.OffsetFromReferenceLine is the distance parallel to the reference axis and always within the base (XY) plane of the reference coordinate system. A positive value of IfcMaterialLayerSetUsage.OffsetFromReferenceLine would then point into the positive y-axis of the reference coordinate system. The IfcMaterialLayerSetUsage.DirectionSense defines how the IfcMaterialLayer's are assigned to the reference axis. POSITIVE means in direction to the positive y-axis of the reference coordinate system. The Thickness of each IfcMaterialLayer is provided starting from the OffsetFromReferenceLine and in the direction given by DirectionSense. It is applied without any gap or overlap between two consecutive layers. The TotalThickness of the IfcMaterialLayerSet is the sum of all layer thicknesses. The IfcMaterialLayerSetUsage.LayerSetDirection is always AXIS2. The local placement of the wall uses the the x/y plane for the profile, and the z-axis as the extrusion direction for the wall body. Figure 6.1.3.41.M — Wall material layers
Object Typing	General	This is a further elaboration on an inherited concept. This concept can be applied to the following resources: IfcWallType
Path Connectivity	General	This concept can be applied to the following resources: IfcWall - Walls with equal or lower priority are connected at RelatedElement.
Product Assignment	General	This is a further elaboration on an inherited concept. This concept can be applied to the following resources: IfcStructuralSurfaceMember - An idealized structural member corresponding to the wall. IfcTask - A task for operating on the wall.
Property Sets for Objects	General	This is a further elaboration on an inherited concept. This concept can be applied to the following resources: Pset_ConcreteElementGeneral Pset_PrecastConcreteElementFabrication Pset_PrecastConcreteElementGeneral Pset_RoadGuardElement (only applies to `PARAPET)` Pset_ReinforcementBarPitchOfWall Pset_WallCommon
Quantity Sets	General	This is a further elaboration on an inherited concept. This concept can be applied to the following resources: Qto_WallBaseQuantities
Spatial Containment	General	This is a further elaboration on an inherited concept. The IfcWall, as any subtype of IfcBuiltElement, may participate alternatively in one of the two different containment relationships: the Spatial Containment (defined here), or the Element Composition.
Surface Geometry	General	This is a further elaboration on an inherited concept. 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).
Element Openings	General	This concept can be applied to the following resources: IfcDoor IfcWindow
Material Set	General	This concept can be applied to the following resources: LoadBearing Insulation

6.1.3.41.7 Examples

Figure 6.1.3.41.N

Wall Extrusion
Figure 6.1.3.41.O

Construction Scheduling Task

6.1.3.41.8 Formal representation

 ENTITY IfcWall
 SUPERTYPE OF (ONEOF
	(IfcWallStandardCase))
 SUBTYPE OF (IfcBuiltElement);
	PredefinedType : OPTIONAL IfcWallTypeEnum;
 WHERE
	CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR
 (PredefinedType <> IfcWallTypeEnum.USERDEFINED) OR
 ((PredefinedType = IfcWallTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
	CorrectTypeAssigned : (SIZEOF(IsTypedBy) = 0) OR
  ('IFC4X3_DEV_738df036.IFCWALLTYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));
END_ENTITY;