Application for construction site access denied

Was there a preliminary building enquiry or something similar?

The plot is buildable (according to the surrounding development).

A preliminary building enquiry is used to get written confirmation that you are allowed to build what you want. Not every plot that is theoretically buildable is ultimately practically buildable, for example if no development (infrastructure connection) is possible. I also repeat ’s suggestion: please post the site plan here as well as a screenshot from Google Maps showing the street. Preferably in different zoom levels.

A building inquiry serves to obtain written confirmation that one is allowed to build what one wants.

Nonsense. As part of the examination of the municipality's statement, this is checked according to § 4 BbgBO (and similarly in other federal states). There is even a special field for it on the form...

has been resolved - it was an error on the part of the city. The application was incorrectly processed by the representative. Of course, we have the right to use a construction site crossing (we just need to contact the company regarding the assignment agreement). The rest is approved...