I would use Walls for the vertical walls.
I would probably use the Roof Tool for the sloping parts.
You could cut the holes for the Windows into the Roof with the Roof tool.
Then you could use the Curtain Wall Tool to create the Windows that go into those holes. Curtain Walls are good for this because you can create any polygonal shape and you can rotate it in 3D any way you like.
The Wall-Roof intersections can be done perfectly using Trim to Roof, or Solid Element Operation, which I like even more since it is an associative relationship.
Loving Archicad since 1995 - Find Archicad Tips at x.com/laszlonagy
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2x28" (2560x1440), Windows 10 PRO ENG, Ac20-Ac27