It seems like Revit doesn't give fully correct info about components while exporting to IFC?
I have an example where my IFC exported model shows up with some "fancy architectual accessories" when I open it in Tekla BIMsight. There are several walls that does not snap to the roof as in Revit.
I also experience that Revit doesn't export the correct IFC information for use in 3 part programs for calculation, I have tried SmartKalk by Holte, and that didn't work out at all.