The built element comprises all elements that are primarily part of the construction of a built facility, i.e., its structural and space separating system. Built elements are all physically existent and tangible things. 

This IfcBuiltElement is a generalization of all elements that are major functional parts of the structural or space separation system of a built facility. Typical examples of IfcBuiltElement's are (among others):

• built elements within a space separation systems
• built elements within an enclosure system (such as a facade)
• built elements within a fenestration system
• built elements within a load bearing system
• built elements within a foundation system
• built elements within an infrastructure facility

For example, built elements are curtain wall, doors, and others in case of buildings; walls, columns, pile, beams in case of buildings or infrastructure works, bearings in case of bridges, pavements in case of roads or rails in case of railways.

The deprecated IfcBuildingElementProxy is not used to represent any arbitrary built element in newer releases, use a direct instantiation of IfcBuiltElement instead. 

changes 

• IFC4X3 changes: The entity has been renamed from IfcBuildingElement and made non abstract.