Single-family house with offset shed roof - KfW consideration

unlimited special repayment

Ok, that is certainly an interesting point. But since we are financing with a mix of a home savings contract and a loan, and with the home savings contract we also have unlimited special repayments.

Everything below 55 is done out of conviction and because one can afford the additional costs.

Ok, that is fine with me as well. Because all the points I set in my mind before the energy consultant are all at the level of KfW 55.

I think I understood that you want KfW40 with single-layer aerated concrete. What is not clear to me: what is the priority of these three key points - so, if you had to cut one of the three wishes, which one would be the first to waver?

Ok, maybe I didn’t write that clearly, yes. I definitely don’t want an ETICS and have now imagined aerated concrete as the building material. But the additional costs for lambda 0.07 in 42.5 cm are already immense. And if I don’t even reach KfW 40 with that, then I will choose a cheaper block.
What do you mean by 3 key points? Windows, door, and block?
I have no problem investing a bit more in any of these points, but more at every point is too much just to reach a number.
As I said, I would be all in for KfW 55. But I don’t think I see the added effort justified for that.

What do you mean by 3 corner points? Window, door, and stone?

No, I had listed them: KfW40, aerated concrete, and single-layer.

I definitely don’t want ETICS and have now considered aerated concrete as a building material.

... one could read that as: ETICS only not, but a second shell (stone, air layer, different or the same stone again) would indeed be debatable (?)

Interesting thought, but isn’t the effort in processing also significantly higher? Which also increases the wall thickness, right? I think I’ll stick to a simple monolithic wall structure of 36 or 42 cm.

So there are still the other two left: KfW40 or aerated concrete - which one would be more important to you?