Currrently in the Ifc reader there is the option to substract openings from their parent feature geometry. However if you make that choice, the geometry of IfcOpeningElement will no longer be available. If you choose not to do so, you can use the CSGBuilder to reproduce the holes, but with a risk of keeping 'Wallpaper' geometries.
I would like to have the option to substract the openings, but also to keep the geometrie available. This way it is possible to rebuild the relationships in a later stage, but also to use the geometries of the IfcOpeningElement for other purposes, e.g. if a OpeningElement isn't filled.
