Single-family house with a ground-level granny flat on a slope

So it's nonsense that the (prefabricated) garage under the house costs more than the (prefabricated) basement?

Because then it might be smarter to leave out the garage entirely, instead there would be parking spaces to the east next to the houses and you could reach the northern entrance doors via a few stairs from the parking spaces.

Of course that's nonsense, why should a basement be made to vibrate by a car?

That's what I've been saying for several pages. A separate basement/garage under the house is nonsense. The basement level preserves the slope.

Apparently it is the house that vibrates when the basement becomes the garage. They don’t want a basement either because apparently even after KfW55 funding it is still more expensive than a pure utility basement. Maybe a really stupid question: what does it depend on whether I have to have a full or partial basement, or what is cheaper? Apparently, the opinions of the construction companies differ on this.

The expanded clay walls are interesting. However, I don't know if they are really that good without insulation.

I have lived in monolithic pumice for at least forty years (which is not quite the same). In midsummer, it is already uncomfortably warm at night in bedrooms without a fan.

what does it depend on whether I have to fully or partially basement a house or what is more economical?

Three-quarter partial basements are economically pointless, half partial basements cost three quarters; very roughly, you can take the square root from the area.

Living spaces are more expensive than utility rooms, so that fits. If you count the basement as living space and reduce the other floors accordingly, you come out cheaper. Now you are paying for a garage instead of a carport, 40 sqm hallway, and a lot of additional cellar space.

If you really want a level with the [Einliegerwohnung], take the levels as suggested in section 3 of [Hanghaus]. The driveway is a bit steeper. No basement and that is the cheaper solution. Just the earthworks alone argue for 2 levels. If you want 3, put the [Einliegerwohnung] on the 1st level so that roughly the area of the roof terrace is eliminated.

40 sqm hallway

Is that actually the new Corona vestibule for greeting/farewell to five people each with one and a half meters distance? Spontaneously, I would otherwise say that normal consumers hold champagne receptions with brass bands so rarely that such a large hallway would hardly be worth it – although: "I'm building a house for my ninetieth birthday, where the mayor brings flowers" is of course also a sympathetic attitude (if you can afford it). However, the latter seems to me to be the keyword: just to excavate one hundred and twenty cubic meters more slope for this room alone also costs a sum that I would rather transfer to my KdF savings book in Zuffenhausen ;-)