The MEP(mechanical, electrical, plumbing) import is right now basically geometry only. The objects created in Revit are for show, they can be used for references but are in practice not possible to reuse. Imported HVAC items and are mostly mapped to incorrect categories and incorrect types. Duct- and pipe fittings are modeled as polygons with way too many vertices instead of swept profiles, which (in addition to the CPU and GPU workload) means each single fitting is a unique type. Spaces are a mess, they don't relate to the Revit concepts of rooms or spaces at all, but are instead created as "generic model" fixed geometrical objects that must be edited as families instead of unique items. Concerning ARCH-IFC's: Voids are converted to solid "generic models", so openings for windows and doors turn into solid boxes that stick out ~10m out of all openings, creating a lot of visual noise. All lines shorter than a certain threshold (think it's 1/4 inch) are automatically deleted during import. This results in that spaces that work fine in ArchiCAD and Solibri because the loops of the bounding elements are closed with short segments (in the joints between walls and windows) are broken during import to Revit. My wish is to enable round-tripping, meaning that it should be possible to pick an IFC-file of an existing project and keep using it, instead of having to create a new one for each refurbishment project. We struggle with this in every single project involving existing buildings, the hours spent circumventing these issues are considerable.
