So I've looked high and low for a solution to this but cant find anything that works. I'll try my best to accurately explain the situation.
I'm creating bonus space above the garage connected to the main house via a breezeway. The breezeway will have a second floor acting as a corridor into the bonus room above the garage. The garage gable/rafters will sit on top of the 3/4 plywood above the garage.
The roof over the garage is only an 8 pitch, and the garage is 24x24 so I'll only have about 8 feet total from sub-floor to the top of the rafters. Even with a 10 pitch there still isn't much height to work with. So, I want to build 3-4' knee walls around the garage to give me more head space to work with and so my ceiling joists will essentailly act as collar ties for the structure. So essentially the front and rear gable walls will be built with an extra 4 feet of wall for the rafters to sit on. I'm just bringing the whole gable roof above the garage up a few feet.
The only option I can find in Chief Architect is to change the ceiling height, but that's not what I need. I still want a standard ceiling here (97 1/8" to be exact), but in this scenario the ceiling joists will be attached inside the rafters rather than on top of a wall like in a typical situation.
So how do I add just 4 foot walls around the garage (2 of them being full gable walls of course) without changing ceiling height?
Thanks!