Terrace planning for a corner terraced house with a large garden - What to consider?

Small correction: I am allowed to build up to the neighbor's boundary as you wrote that 7x3x2.50 would not be a problem and that you would approve it; 7m is the house width, only the depth is the problem, that you have rejected 4m.

One district over, they don't have them,

Doesn't matter at all. It might be the same in Beijing or Timbuktu. From that, you can derive the same rights as from the district next door.
Right next to me, you also don't have to make an emergency lane on the highway. Here with me, it costs a fine if I don't do it. That's how it is, as was told to the federal government.

The employees of the building authority will hardly make use of their discretion. Because otherwise the next neighbor comes, just like you, and checks what went on with the neighbors.

However, it is still uncertain whether the building limit will be lifted, because it dates from 1980 or 85 and the plots have been divided, and the division also causes other problems. My neighboring plot is still undeveloped; it belongs to the same owner from whom we bought, he is now retired but was employed at the building authority of another federal state. He is getting the plots divided (3), not sold, because although three great houses can be built through the division, they would be above the building limit, and he told me that he wants to apply for this. However, everything would take some time. We also do not want to build the roofing that quickly yet.. I still filed an objection. Of course, you cannot build beyond the building limit indefinitely, but one that might be lifted, or if you are already allowed to build beyond it, then for a reasonable depth, so that it at least makes sense. I do not want a depth of 5m, but 4, so that you can sit at the table. I can try, let's see what comes out.

Sorry, the building boundary is not being lifted, but extended by a few meters. Therefore, it could be that I am allowed to build over it anyway. Since the other houses in Reuhe are built further ahead and so that they can still have a terrace plus a roof, this has to be done and there are other problems as well, but at least it can be attempted. I definitely have the 3m.

I don't want 5m deep, but 4, so you can sit at the table. I can try, let's see what comes out.

I also want to win 20 million in the lottery, not 15.20 euros. For me, this whole thread is a prime example of "Me first". Everyone is supposed to follow the rules, but because I want to sit at a big table, I don't want to. No understanding on my part. You knew what you were buying.