Nice plot of land, but is the development plan too restrictive?

A garage with a height of 2.50 makes no sense at all anymore.

Yep. The 3m high SUV no longer fits in. Only all normal cars...

Even the front yard is regulated.

That is still the case today. In all state building codes it now says that non-built-up areas must be designed to be water-permeable and greened/planted. Sealing + gravel gardens are prohibited throughout Germany - basically old development plan 2.0.

Because it was asked: The building window is 10m wide and 16m deep. I also have a picture of the back of the property. You can clearly see, I think, that the two neighboring houses do not have 25° roofs. Also barely visible is that the outbuilding at the back of the neighbor on the left definitely does not have a flat roof. I have already made an inquiry to the building authority, but I still have to decide this week whether to make an offer on the property, so I do not expect a timely response there.

Have you ever rung the neighbors' doorbell and asked for their building permit or exemption from the regulations?

Have you ever knocked on the neighbors' doors and asked about their building permit or exemption from the regulations?

Unfortunately, it is currently difficult. When we were on site, the offer was already offline again, so I assumed it was already taken. Only afterwards did it turn out that there was simply a lot of demand and we have one week to submit our offer. And now I am on a business trip until after the deadline...

So, on 16x10m, you can also build a proper single-family house on one level. Roughly speaking, that would be about 130sqm of living space without attic development.

Are there any restrictions at all? What do you want to build or what do you need? A bungalow with 2 rooms under the pitched roof should be possible. Looking at the neighboring buildings, exceptions seem to be possible. There will be no building with 2 VG and a garage for the RV.