Class Ifc4x2::IfcBuildingElement

Nested Relationships

This class is a nested type of Struct Ifc4x2.

Inheritance Relationships

Base Type

Derived Types

Class Documentation

class Ifc4x2::IfcBuildingElement : public Ifc4x2::IfcElement

Definition from ISO 6707-1:1989: Major functional part of a building, examples are foundation, floor, roof, wall. The building element comprises all elements that are primarily part of the construction of a building, i.e., its structural and space separating system. EXAMPLEs of building elements are walls, beams, or doors, they are all physically existent and tangible things. The IfcBuildingElement utilizes the following capabilities mainly through inverse attributes referencing objectified relationships: NOTE View definitions and implementer agreements will determine those relationships that have to be supported in actual exchange.

Grouping - being part of a logical group of objects

objectified relationship: IfcRelAssignsToGroup object referenced by relationship: IfcGroup (and subtypes) inverse attribute: HasAssignment

Work processes - reference to work tasks, in which this building element is used

objectified relationship: IfcRelAssignsToProcess object referenced by relationship: IfcProcess (and subtypes) inverse attribute: HasAssignments

Structural member reference - information whether the building element is represented in a structural analysis model by a structural member

objectified relationship: IfcRelAssignsToProduct object referenced by relationship: IfcStructuralMember (and by default IfcStructuralCurveMember) inverse attribute: HasAssignments

Aggregation - aggregated together with other elements to form an aggregate

objectified relationship: IfcRelAggregates object referenced by relationship: IfcElement (and subtypes) inverse attribute (for container): IsDecomposedBy inverse attribute (for contained parts): Decomposes

Material - assignment of material used by this building element

objectified relationship: IfcRelAssociatesMaterial object referenced by relationship: IfcMaterialSelect (and selected items) inverse attribute: HasAssociations

Classification - assigned reference to an external classification

objectified relationship: IfcRelAssociatesClassification object referenced by relationship: IfcClassificationNotationSelect (and selected items, default IfcClassificationReference) inverse attribute: HasAssociations

Library - assigned reference to an external library item reference

objectified relationship: IfcRelAssociatesClassification object referenced by relationship: IfcLibrarySelect (and selected items, default IfcLibraryReference) inverse attribute: HasAssociations

Documentation - assigned reference to an external documentation

objectified relationship: IfcRelAssociatesDocumentation object referenced by relationship: IfcDocumentSelect (and selected items, default IfcDocumentReference) inverse attribute: HasAssociations

Type - reference to the common product type information for the element occurrence

objectified relationship: IfcRelDefinesByType object referenced by relationship: IfcBuildingElementType (and subtypes) inverse attribute: IsTypedBy

Properties - reference to all attached properties, including quantities

objectified relationship: IfcRelDefinesByProperties object referenced by relationship: IfcPropertySetDefinition (default IfcPropertySet) inverse attribute: IsDefinedBy

Connection - connectivity to other elements, including the definition of the joint

objectified relationship: IfcRelConnectsElements object referenced by relationship: IfcElement inverse attribute: ConnectedTo inverse attribute: ConnectedFrom

Realization - information, whether the building element is used to realize a connection (e.g. as a weld in a connection between two members)

objectified relationship: IfcRelConnectsWithRealizingElements object referenced by relationship: IfcElement inverse attribute: IsConnectionRealization

Assignment to spatial structure - hierarchical assignment to the right level within the spatial structure

objectified relationship: IfcRelContainedInSpatialStructure object referenced by relationship: IfcSpatialStructureElement inverse attribute: ContainedInStructure

Reference to spatial structure(s) - non hierarchical reference to one or more elements within the spatial structure (e.g. a curtain wall, being contained in the building, references several stories)

objectified relationship: IfcRelContainedInSpatialStructure object referenced by relationship: IfcSpatialElement inverse attribute: ContainedInStructure

Boundary - provision of space boundaries by this building element

objectified relationship: IfcRelSpaceBoundary object referenced by relationship: IfcSpace inverse attribute: ProvidesBoundaries

Coverings - assignment of covering elements to this building element (note: normally covering elements are assigned to the space, only used for special cases)

objectified relationship: IfcRelCoversBldgElements object referenced by relationship: IfcCovering inverse attribute: HasCoverings

Voids - information, whether the building element includes openings, recesses or other voids

objectified relationship: IfcRelVoidsElement object referenced by relationship: IfcFeatureElementSubtraction (default IfcOpeningElement) inverse attribute: HasOpenings

Projection - information, whether the building element has projections (such as a fascia)

objectified relationship: IfcRelProjectsElement object referenced by relationship: IfcFeatureElementAddition (default IfcProjectionElement) inverse attribute: HasProjections

Filling - information whether the building element is used to fill openings

objectified relationship: IfcRelFillsElement object referenced by relationship: IfcOpeningElement inverse attribute: FillsVoids

HISTORY New entity in IFC Release 1.0

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

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

RepresentationIdentifier : ‘Box’ RepresentationType : ‘BoundingBox’

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

Figure 22 — Building element box representation

Axis Representation Some IfcBuildingElement may be represented by an axis as an abstract geometric representation. See each subtype for specific guidance. The following attribute values for the IfcShapeRepresentation holding this geometric representation are used:

RepresentationIdentifier : ‘Axis’ RepresentationType : ‘Curve2D’, ‘Curve3D’

Surface Representation Some IfcBuildingElement may be represented by an surface as an abstract geometric representation. See each subtype for specific guidance. The following attribute values for the IfcShapeRepresentation holding this geometric representation are used:

RepresentationIdentifier : ‘Surface’ RepresentationType : ‘Surface2D’, ‘Surface3D’

FootPrint Representation Any IfcBuildingElement may be represented by a footprint as a specific floor plan geometric representation. See each subtype for specific guidance. The following attribute values for the IfcShapeRepresentation holding this geometric representation are used:

RepresentationIdentifier : ‘FootPrint’ RepresentationType : ‘GeometricCurveSet’, ‘Annotation2D’

Body Representation The body representation of any IfcBuildingElement can have the following representation types: ‘SurfaceModel’, ‘Brep’, ‘AdvancedBrep’, and ‘MappedRepresentation’. Other representation types might be specified at the level of subtypes. SurfaceModel Representation Type Any IfcBuildingElement (so far no further constraints are defined at the level of its subtypes) may be represented as a single or multiple surface models, based on either shell or face based models. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘SurfaceModel’

In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.

As shown in Figure 23, the surface model representation is given by an IfcShapeRepresentation, which includes a single item which is either:

IfcShellBasedSurfaceModel, or IfcFaceBasedSurfaceModel.

Figure 23 — Building element surface model representation

Brep Representation Type Any IfcBuildingElement (so far no further constraints are defined at the level of its subtypes) may be represented as a single or multiple Boundary Representation elements (which are restricted to faceted Brep with or without voids). The Brep representation allows for the representation of complex element shape. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘Brep’

In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape. As shown in Figure 24, the Brep representation is given by an IfcShapeRepresentation, which includes one or more items, all of type IfcFacetedBrep.

Figure 24 — Building element body boundary representation

AdvancedBrep Representation Type An IfcBuildingElement (so far no further constraints are defined at the level of its subtypes or by view definitions) may be represented as a single or multiple Boundary Representation elements (which are based on advanced surfaces, usually refered to as NURBS surfaces). The AdvancedBrep representation allows for the representation of complex free-form element shape. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘AdvancedBrep’

In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape. MappedRepresentation Representation Type Any IfcBuildingElement (so far no further constraints are defined at the level of its subtypes) may be represented using the MappedRepresentation. This shall be supported as it allows for reusing the geometry definition of a type at all occurrences of the same type. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘MappedRepresentation’

The same constraints, as given for ‘SurfaceModel’, ‘Brep’, and ‘AdvancedBrep’ geometric representation, shall apply to the MappedRepresentation of the IfcRepresentationMap.

Subclassed by Ifc4x2::IfcBeam, Ifc4x2::IfcBearing, Ifc4x2::IfcBuildingElementProxy, Ifc4x2::IfcChimney, Ifc4x2::IfcColumn, Ifc4x2::IfcCovering, Ifc4x2::IfcCurtainWall, Ifc4x2::IfcDeepFoundation, Ifc4x2::IfcDoor, Ifc4x2::IfcFooting, Ifc4x2::IfcMember, Ifc4x2::IfcPlate, Ifc4x2::IfcRailing, Ifc4x2::IfcRamp, Ifc4x2::IfcRampFlight, Ifc4x2::IfcRoof, Ifc4x2::IfcShadingDevice, Ifc4x2::IfcSlab, Ifc4x2::IfcStair, Ifc4x2::IfcStairFlight, Ifc4x2::IfcWall, Ifc4x2::IfcWindow

Public Types

typedef IfcTemplatedEntityList<IfcBuildingElement> list

Public Functions

const IfcParse::entity &declaration() const
IfcBuildingElement(IfcEntityInstanceData *e)
IfcBuildingElement(std::string v1_GlobalId, ::Ifc4x2::IfcOwnerHistory *v2_OwnerHistory, boost::optional<std::string> v3_Name, boost::optional<std::string> v4_Description, boost::optional<std::string> v5_ObjectType, ::Ifc4x2::IfcObjectPlacement *v6_ObjectPlacement, ::Ifc4x2::IfcProductRepresentation *v7_Representation, boost::optional<std::string> v8_Tag)

Public Static Functions

const IfcParse::entity &Class()