Winter garden conversion - building permit required or permit-free?

I wrote to Steven

Why didn't you use a clarification procedure? Was that not considered?

Hello Alex85 No idea. My architect did it that way. Steven

Hello everyone,
I am thrilled about so many responses. I will definitely contact the responsible person at the building authority next week. Maybe it will help. Construction is supposed to start by June since our street will be developed for 2 years (probably with a full closure), then it will be almost impossible to get materials here.
As for the development plan... they are currently building in every free space... and what kind of structures just to fit into the narrowest corners. The neighborhood is very popular at the moment.
We are one of the few houses that is not even built on a second row.

Best regards

As far as the development plan is concerned... right now, every free gap is being built on....

That alone does not necessarily mean that a development plan is being established (which is not bad, then the "integration requirement" according to §34 applies).

We are one of the few houses that is not even built in the second row.

However, this would be a reason to establish a development plan: if it is currently regularly expected that the back gardens will be developed.

A development plan is not a prerequisite for possible building permits; it merely creates the clarity about the "how" (which is regularly desired in new development areas and systematic densification of existing settlements), which otherwise, simplified, is derived from the surrounding existing buildings.