Anyway, this is an opportunities to show what happen with the roof I designed :
So first, I trace the floor plan :
Then I build up the walls :
.. I never get any best practise for 2nd floor ... so I did same than 1st floor. I built the floor, I draw the plan on it and I build up the walls :
My first error here is I don't designed door and windows on the plan ... anyway, I did them be extrusion but I think it would be more confortable from the plan.
to be continued...