If at 50cm. height (from inner floor level) I extrude a 10 cm. slab, 2.0m. on its base for 40cm., then I make it narrow @ 45° another 40 cm., and have a flat end.

I do it again at 180cm. (from inner floor level).

Then I place 5 windows to make it a "Bay window".

Just tell me, how I can do this?

please