There will surely be more to add, but for now we wantto add layers:
A_FOUNDATION; A_WALL FRAMING; A_ROOF FRAMING.
There is already a slab layer, but this is different than foundation (on many buildings) and there is A_WALL STUDS, but the framing oine is more general, and would cover other structural members in the wall that were not studs. the same thing applies to the roof framing.
Any more suggestions are welcome.
