I have a model of a 2-storey house with a front-facing attached garage. The garage sits about 2' lower than the 1st floor. As a result, the 2nd floor walls do not attach to the garage walls. There is an awkward gap between the garage roof and the bottom of the 2nd floor walls. Is there a way to "split" the 2nd storey walls and attach the bottoms to the top of the garage walls? I have attached a picture for more clarification. Any help with this issue would be greatly appreciated, Thanks!