Thanks Emmanuel!

inner polygons seem to be generally accurate

Of course, are made with your code from PlanControler.
The part responsible with roof computation (partially mine, partially stolen) don't work as expected.
I will let this path for other volunteers(if any).
As I've already say, I will try another approach (if the life time hope permit).
I've study about 3D Plane equation for few weeks and appear is not so complicated as seems at first view.
For this version I've work in frog, with out a plan and try, test and fail without a clear target.
The main path remain the same:
roof projection -> compute roof -> create shape -> add to Home Plane.
Now I'll try to be more clearly organized. I've start to make a logical diagram for this plugin like in '70+ years. I will put it here when I have first version.