Thank you very much for your answers. In any case, I take away that there were also some positive examples. One week would of course be great!
We have already contacted the building authority and promptly received a response. There were also some platitudes – about how I have the right to contact the responsible representatives of my district. But there was also the tip that instead of a building application, one could possibly switch to a building notification (§62 Brandenburg Building Code). This is usually processed much faster. We have now passed this information on to our architect for the time being. Let’s see what comes of it.
P.S.: Regarding the topic of wasteful spending. If I had no children, I might partly be on the side of the opponents of the Baukindergeld. But if you’re not rich, having or not having €36,000 is a huge, fat difference. I think most here will support me in this opinion.