We are working on a project which has a large window seat / bay Window which extrudes / cantilevers on second floor over a garage. The window seat cantilevers out about 2'-0" from the room and is a few feet over the garage roof. It should not touch any wall below. As soon as we close the walls of this "room" it adopts the garage floor and ceiling information completely destroying our design intent. We have tried all kinds of different ways of doing this with no progress. The drawing I attached has no walls on the window seat which is something new since the last time I opened it (the walls were there!) Can someone please help?
I attached the file and a concept drawing of what our boss wants.