EXAMPLEs of building elements are walls, beams, or doors, they are all physically existent and tangible things.

They are separated from other elements, since they are dealt with in separate AEC processes. The IfcBuildingElement utilizes the following capabilities mainly through inverse referenced to objectified relationships:

1. Grouping - being part of a logical group of objects
2. Classification - assigned reference to an external classification
3. Documentation - assigned reference to an external documentation
4. Type - reference to the product type information for the element occurrence
5. Properties - reference to all attached properties, including quantities
6. Cost control - reference to cost elements associated with this building element
7. Work processes - reference to work tasks, in which this building element is used
8. Aggregation - aggregated together with other elements to form an aggregate
9. Connection - connectivity to other elements, including the definition of the joint
10. Assignment to spatial structure - hierachical assignement to the right level within the spatial structure
11. Material - assignment of material used by this building element
12. Boundary - provision of space boundaries through this building element
13. Opening - information, whether the building element includes openings
14. Filling - information whether the building element is used to fill openings

HISTORY New entity in IFC Release 1.0
ISSUE See issue log for changes made in IFC Release 1.5, see issue and change log for changes made in IFC Release 2x.

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 contraints are defined at the level of its subtypes.

Bounding 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 simpliest geometric representation available. It is ensured by assigning the value 'BoundingBox' to the RepresentationType attribute of IfcShapeRepresentation.

The bounding box representation is given by an IfcShapeRepresentation, which includes a single item, an IfcBoundingBox.

SurfaceModel Representation

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. It is ensured by assigning the value 'SurfaceModel' to the RepresentationType attribute of IfcShapeRepresentation. In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.

The surface model representation is given by an IfcShapeRepresentation, which includes a single item, which is either: IfcShellBasedSurfaceModel, or IfcFaceBasedSurfaceModel.

Brep Representation

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. It is ensured by assigning the value 'Brep' to the RepresentationType attribute of IfcShapeRepresentation. In some cases it may be useful to also expose a simple representation as a bounding box representation of the same complex shape.

TheBrep representation is given by an IfcShapeRepresentation, which includes one or more items, all of type IfcManifoldSolidBrep.