Are neighborhood signatures required for subordinate components?

Hello,

we are going to build a semi-detached house in Bavaria on a plot for which there is a development plan.
The whole area is in an old settlement area and the neighbors all around are not happy that construction is now taking place here.
Basically, a building that fully complies with the development plan cannot be prevented by the neighbors.

My question now is how it looks with a subordinate structural element? The house is 7 m x 10 m, which fully utilizes the building boundary. On the 2nd floor, we would like to have a small bay window as a subordinate structural element, which would of course extend beyond the building boundary.
If the neighbor, on whose side the bay window extends, does not sign, is that then problematic for the approval?

Give the neighbors reasons to be happy. Then a lot will work out.

Fundamentally, a construction that fully complies with the development plan cannot be prevented by the neighbors.

This statement is incorrect, as compliance with the planning law regulations (development plan) does not generally exclude building code violations (e.g., setback requirements).

subordinate building component

I assume this classification is based on Art. 6, paragraph 8 BayBO. This is building code law that protects neighbors.

beyond the building boundary

This is urban planning law. It only has neighbor-protecting effect in few cases.

is that then problematic for the approval?

If the building code law is complied with, the authority must assess whether in this individual case the building boundary has a neighbor-protecting effect. Since §23, paragraph 3, Baunutzungsverordnung A slight projection of building parts may be permitted. is a discretionary provision, the absence of a signature entails conflict potential, which could be defused by non-use. In short: As a caseworker, I would not allow exceeding the building boundary if the signature is missing.

The house is 7 m x 10 m, which also fully utilizes the building boundary. On the 2nd floor, we would like a small bay window as a subordinate element, which of course would then extend beyond the building boundary.

Do you want to increase the 7-meter width to 7.50 m with the bay window at about half the length?