New single-family house on sloping plot

Correct, it is the neighbor on the right, as shown in #23. The development plan is from 1984 and is therefore no longer up to date. The building authority said that what is approved for neighbors will also be approved for us. The garages are also marked at the front in the development plan. The neighbor now also has them in the house.

Well, with the OP, I think it's directly the neighbor, if you believe the map in #23. At least it looks like it.

It's the hairpin, hence the adjustment of the ridge. That was planned exactly like that for us on the curves.

That can of course be the case. Stupid. Then we would have to work with dormers on the upper floor.

So read the statutes carefully! The symbols are often only exemplary.

So read carefully

and write it down too.
I can't make sense of the information. Number of floors is 2 but maximum knee wall height is 1.125m? How does that work together?

Well, two-story = ground floor plus upper floor, whereby actually the knee wall in the upper floor may only be a maximum of 50 cm. However, 1.125 meters were approved all around.