Baulast for building a 9-meter boundary garage in NRW

Hello everyone,

somehow I am a bit confused about the planning consultation and building consultation of the city of Oberhausen. I would like to have a 9m garage built instead of a 6m garage (so to speak an extension on the garden side). Now, as far as I know, this should be exempt from approval. However, the lady at the planning consultation now tells me that I have to get the willingness for a building encumbrance. But for 9m that is not necessary, is it?

Best regards

Is this the only boundary construction? Because there is also the maximum of 15m as the total length of all boundary constructions, maybe that is the problem?

This should be the only boundary construction. At first, I also wanted to put a carport in front of the garage. But then I would have to (I think) get permission from the neighbor.

...The lady at the planning consultation is now telling me that I have to obtain the commitment for a building encumbrance.

What exactly is this building encumbrance supposed to regulate?
In whose favor?

A building encumbrance alone is not necessarily harmful.