Boundary construction carport

We had an old small house demolished and applied for a larger new building with a 9 m long carport as a boundary structure. The approval has been granted. Now the neighbor says - next to the carport - that we still have to make an agreement with him. After all, a building encumbrance would have to be registered with him. On his side, there is no boundary structure but only a garden. What is the legal situation?

I would say that if you have a permit from the building authority, then it is approved. If such an agreement had been necessary, you would not have received the permit and the building authority would have had to inform you. At least that was the case for us.... I don't quite understand why a building encumbrance has to be registered for him. Just ask the building authority.

No building encumbrance is required, at least if you adhere to the specified heights of the carport.

If the approval is granted, everything is fine, your neighbor just wants to act important. Registration with him is not necessary if approval is granted.

How is it legally?

Approved to be viewed quite relaxed. If I remember correctly, the property is also so flat that a wall height problem seems unlikely to me.