The matter with the garden house is settled for now, thanks. According to the architect (she has contacted the building authority), it will probably not be a problem, but we will include it in the building application. Although our neighborhood law does not specify exact dimensions, it states the volume the house may have. In our case, I quote:
„according to § 50 exempt projects (appendix)
1. Buildings and building parts
a) Buildings without habitable rooms, toilets, or fireplaces, if the buildings are neither for sales nor exhibition purposes, up to 40 m³ gross volume in inner areas, up to 20 m³ in outer areas,
…
f) Garden houses in garden house areas,
g) Garden arbors in allotment gardens within the meaning of § 1 para. 1 of the Federal Allotment Garden Act…“
And regarding the setback areas of the garden house:
(1) In the setback areas of structural facilities as well as without their own setback areas, the following are permitted:
2. Garages, greenhouses, and buildings without habitable rooms with a wall height of up to 3 m and a wall area of up to 25 m²,
The same applies to the fences. According to the architect, we do not even need to include them in the building application. Regarding visual obstructions, etc., sight fields are marked in our development plan, but these do not concern us.
Regarding turning the roof: we are not even allowed to turn it a tiny bit. The city says no.
However, we have received an exemption for the knee wall and the dormer.
HAHA, I am less concerned about being attacked. It's just that if there isn’t a camera installed, I don’t know if someone is standing in front of the door with whom I want to talk. So I’d rather not open. The important people will always announce themselves in advance.