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How to associate IfcManifoldSolidBrep with IFCWall


I read through the IFCWall spec and would like to know how to export a manifold solid brep into IFCWall type without explicitly specific parameters for a wall object (Height, Width, Length…)?

I could export the manifold solid brep object into IfcManifoldSolidBrep object, then is there any way to associate the IfcManifoldSolidBrep with an IFCWall object?

Thank you in advance!



those type of questions are answered by the “fundamental concepts” of the IFC specification. They provide you with a path from the elements (e.g. wall, beam, air outlet) to the associated objects (material, geometry, properties, etc.)

for IFC4, see

in particular for manifold breps:

faceted breps:



Thank you TLiebich. I digested the link a little bit so take a while to feedback. The information is very helpful to me. From my understanding if the IFCWall want associate with a manifold solid brep, the brep must be surface type (i.e. faceted breps). If I want export a solid brep with a wall, then parameters definitions have to be provided (via IfcExtrudedAreaSolid object).

Does my understanding sounds right?