What questions should be asked to the building authority?

Actually, I want to talk about it with as few people as possible... I'm afraid someone will snatch it away from me. There are no building plots here, the thing is like a treasure! Actually too good to be true. I don't want to wake sleeping dogs.

I just studied the plans and saw that the house planned in 2001 was built on the neighboring property. In any case, it looks exactly like in the building application. Maybe the client got the neighboring property at short notice and that's why it wasn't built. I feel like Sherlock Holmes!

There is even a building application from 2001 that was approved. We don't know why it wasn't built. But I have located the architect. Should I give him a call...?

Anyway, this approval is no longer valid.
So there is a development plan. Why aren't the houses adapted to the plan? Were the houses built before the development plan?
Anyway: I don't think it should be a problem for you to want to adapt to the row of buildings.

But there are already development plans.

There can only be one! However, in that case, §34 of the Building Code does not apply, but §30 does.

But they are very vague. Or rather, the neighboring development does not correspond to them.

Whatever that may mean. Questions to the building authority: 1. Is there a development plan? When did it become legally binding? What does it stipulate? What are the prospects for possible deviations? if not see #2 (except for the roof shape, which cannot be prescribed according to §34) 2. Are there other local regulations (design statutes, parking space statutes, tree protection statutes, ...)? 3. Are there construction burdens for or against the property (information possibly subject to a fee)? 4. Are neighborhood agreements known? 5. Have the development costs been paid? Is there any expectation of development costs in the near future, e.g. due to sewer or road renovation? Preparation: 1. Current excerpt from the land registry (geoportal-bw.) 2. Photos of neighboring properties with their development

Wow, those are many good questions. I will ask them first thing tomorrow. I'm just an amateur. I think further explanations will only confuse more. I can't explain it better. Regarding the photos, I am currently on my way to the property. Maybe I will meet some neighbors, then I will question them.

The building authority is being obstructive. The statement was roughly like this: there is no reason for it, except that the plans are simply like that. And a deviation from it can be applied for, but it will probably come to nothing. The only thing I can think of now is to involve nature conservation. Because the property belongs to a protected landscape area and if I have to build on top, I have to flatten everything, otherwise I can't get there at all.