But pitched roofs certainly have about 1 to 2 supports,
I would have expected those here as well, then the wall thickness of 12 cm (= a beam dimension usual in this size) would make sense. According to the section drawing, however, there are probably only double clamps and the braces that keep the shape stable.
which you don’t see like that.
In the gable-parallel walls, for example at the stair exit and at the intersection with the bathroom wall, there would have been good places for that, but: see above.