I am getting ready to start building a small addition onto my garage and have a question about the ceiling joists. The addition is going to be 8'x10' with the ceiling joists running the 10' length perpendicular to ridge of the roof. Studs, rafters, and joists are all 16" O/C. The way that I have the design drawn up now has the joists sitting on the top plate of the wall next to the rafters. My father in law suggested that instead of the rafters sitting on the top plate, I should instead attach them to the wall studs directly below the top plate to gain some additional attic space. Does anyone see any issues with doing this? I would definitely like the additional space above, but I don't want to compromise the structure in any way.