How to obtain an exemption from the development plan?

If I have a 50 cm knee wall, then draw a dwarf wall at about 1.20 m (where 1.50 m would probably even be better with the low roof pitch, since at 1.20 m I still have 1.75 m until I reach an edge of 2 m) you simply lose about 20 sqm of floor space completely. And for that, I have to build the house accordingly larger.

but that is like "totally different"... it should actually suit you, because you want to do it differently. Everyone else on other building plans has to build such a weird roof that lost space in the roof occurs. You don’t have that.

I think most are simply satisfied with 500-600 sqm and don’t want to maintain too much garden.

where do you get your wisdom from? Just because you read a lot about city dwellers here who simply live in a completely different structure than villagers? Or because agriculture and animal husbandry are not discussed here? Does everyone have to enter in their avatar how many kg of vegetables they harvest in their garden, how many livestock they have? Are they also "different"? One thing you definitely have in common with all of us: you think independently. And you are special, like each one of us. Your desire to build a house makes you the same as us. Otherwise you wouldn’t be here. And if it were otherwise, we couldn’t even give you an answer.

but that is so „totally different“... it should actually suit you, because you want to do it differently. Everyone else on other B-plans has to build such a strange roof that lost space in the roof is created. You don’t have that.

Interesting argument! But you can also make such a point without sarcasm. Maybe just stay a bit more factual? How long are you going to keep beating this topic to death. I just wanted to point out that our requirements deviate from the norm in a few things. It's enough already.

What interests me about this "Drempel" thing is how to handle the "airtight" layer? Does it still come at the exterior wall and the roof, or basically at the roof and then down at the Drempel? If it is still at the roof and the exterior wall, you can just install the "Drempelwall" yourself with drywall. And I suppose the underfloor heating will probably only go up to this point, right? Maybe someone knows.

What really hurts me is the massively lost space.

That is quite silly. I can understand if someone with 250m² in the city tries to use it as efficiently as possible. But with 900m², I wouldn’t start changing the development plan because of 20m². If the space on the property were that crucial, you would build with a basement.

At first, I thought you had completely taken this sentence out of context just now, but after rereading my paragraph, I realize that it can be misunderstood.

What really hurts me is the massively lost space.
If I have 50 cm knee wall, then build a dwarf wall at about 1.20 m (although 1.50 m would probably be better given the low roof pitch, since at 1.20 m I still have 1.75 m until I reach an edge of 2 m), you simply lose about 20 sqm of floor area completely. And for that, I have to build the house correspondingly larger.

I didn’t mean the plot area, but rather the floor area on the upper floor. So on the sides where the roof is still very low, space is lost because of the dwarf wall.

That the 10 - 20 sqm of plot area that might be lost due to regulations is not that dramatic, I have already written.

But you can also say something like that without sarcasm. Maybe just stay a bit more factual?

No. I am totally different in that regard. I can’t do it.

How long do you want to keep beating this topic? I just wanted to point out that our standards differ from the norm in a few things.

But then we wouldn’t be able to provide answers here. The standard for living, kitchen, and bathroom has to be somewhat the same for everyone so that we know what we are talking about here.

Does it still come at the exterior wall and the roof or basically at the roof and then down at the knee wall?

Normally at the exterior wall and roof, so you can optionally set your knee wall and use the space behind the knee wall for storage.

If it still comes at the roof and the exterior wall, you can simply install the "knee wall" yourself with drywall.

Yes, you could finish your entire attic yourself and save money doing so.

And the underfloor heating will probably only go as far as this, I guess?

If you retrofit the knee wall, the underfloor heating will be laid completely up to the KS, unless you plan it differently from the start. You just have to meet the requirements. Thermal bridge and so on...