A above-ground living basement?

The question is probably more whether you are willing to pay for it.

Whether you want to build your ground floor from concrete and ETICS or from KS and ETICS is technically almost the same. But in the end, no one wants to pay for it.

Whether I am willing to pay a premium is indeed the question. Compared to a cheap timber frame wall with ETICS, yes. Compared to KS, rather not.

I will most likely have to build one-and-a-half stories, white plastered, with a red or black gable roof.

Igittohgott (or vice versa) - the house matching the garden gnome. You’d rather rent nicely than build ugly. Development plans that specify brick colors are usually terrible at stinginess with knee walls.

Whether I want to pay extra is actually the question.

What is your expectation anyway: do you want to save construction time with a cast house, or money?

I have already planned 50 cm wall thickness in my current floor plan for solid masonry.

I can’t really associate that with a "basement" at all (?)

He wants to save money, bet? Some kind of prefabricated building with a pitched roof. Well, anyone who has ever lived in a real panel building, made by VEB Kombinat Völkerfreundschaft, knows how annoying that is. Nothing can be assembled without a state act, not a single nail goes into the wall. Yet these things are still noisy. And they have to be very, very well insulated. The cheapest building material is concrete, but an insulated, airy one, like Ytong or competing products of the same kind. Everyone knows that, except the South German, who always wants brick. That's why he is punished with about 100 thousand more credit, or something like that....

He wants to save money, bet?

He wants another ... full-fledged ... above-ground ... floor, bet??? :)

Here are also a few links and information!

He wants another ... full-fledged... above-ground... floor, bet??? :)

interesting idea, but I’m not allowed to because of the maximum height