HISTORY New entity in IFC Release 1.5.
ISSUES: See issue and change log for changes made in IFC Release 2x.

Geometry Use Definitions:

The geometric representation of IfcDistributionElement is given by the IfcProductDefinitionShape, allowing multiple geometric representation.

Local Placement

The local placement for IfcDistributionElement 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.

• The PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcSpatialStructureElement , which is used in the ContainedInStructure inverse attribute, or to a spatial structure element at a higher level, referenced by that.
• If the relative placement is not used, the absolute placement is defined within the world coordinate system.

Geometric Representation

The geometric representation of IfcDistributionElement is defined using different geometric representation types for the various subtypes. In general, the following guidelines should be used:

• all fixtures (all non distribution flow elements, i.e. everything which is not a duct, pipe or later cable) should be defined by an b-rep - the new mapped item should be used if appropriate as it allows for reusing the geometry definition of the element type at element instances. In this case the IfcShapeRepresentation.RepresentationType = MappedRepresentation.
• all "simple" distribution flow elements (general ducts and pipes) are defined by sweep geometry . In this case the IfcShapeRepresentation.RepresentationType = SweptSolid.
• an additional representation type for all "simple" distribution flow elements (general ducts and pipes) is the ability to have a simple line based representation. In this case the IfcShapeRepresentation.RepresentationType = GeometricSet.
• distribution flow elements with size changes (e.g. reducer) are defined by sectioned sine representations. In this case the IfcShapeRepresentation.RepresentationType = SectionedSpine.
• all complex distribution elements (e.g. Y branch or T branch) are defined using b-rep geometry. In this case the IfcShapeRepresentation.RepresentationType = Brep.