Teun De Vries shared an: “Excel document (download), with which you can build the mapping tables that Revit can use when importing from, or exporting to IFC. It is still a bèta. You can use it or even change it, but at your own risk of course. And if you do so, Teun would love to know what your experiences are. The RevitGG is also using this tool to help build some parts for in the Dutch Revit Standard the DRS.”
