@Quickfragger are you deleting walls in order to remove flooring? The old way we used to create loft spaces was to 1) draw a room for the area where we wanted to remove flooring, 2) delete the floor, 3) delete a wall from the room, flooring would appear to pop back, 4) delete the flooring again, and 5) place a flat over the exposed ceiling area above which would treat the game as interior space again. That old method still works, but there's a better way - instead of deleting any room walls, just replace them with fencing, and the room will be maintained properly.
