Basement costs - Is the floor slab offset?

Listings on the internet about construction topics are often funded by providers, if you ask me. They naturally do not take local conditions and price structures into account. Often, they are also outdated or lack date information to be able to assess this.

100k for a "Wohnkelller" 10x10 is very realistic...

It would be interesting to know which option is actually cheaper. We are currently facing the problem that excavation and disposal are quite expensive here (40€/m³).

If you leave out the basement and simply add an additional floor instead, it should actually be cheaper, since you basically save on the roof construction and the excavation.
Or rather, the roof construction has to be paid for anyway.
However, I save some windows in the basement but have less living space as a result.

The builders here who were able to buy a flat plot of land almost all built without a basement.
That really makes you think.

Civil engineering is almost always more expensive than building construction.

Instead of 2 full stories + basement, we could also build 2 full stories + a recessed floor (+ possibly also with a basement, but we can’t find that much money ), but we prefer the basement. A key reason is the walking distances. The main living area is typically the ground floor; from there I need a staircase to both the upper floor and the basement. To get from the ground floor to the recessed floor, however, I would need to go up two staircases. Which unimportant, infrequently used rooms would I then have to put into the recessed floor to avoid sore feet, and would my floor plan still work as a whole? Filling the "penthouse" with unimportant rooms is also somehow unpleasant to me (a matter of mindset). If the calculation with the basement falls through, the recessed floor remains an option. But this would require a more extensive redesign.

You would just have to plan the [Technik und Hauswirtschaftsraum] on the ground floor. The upper floor for the children and the attic floor for the parents. Then you also don't have long distances. You don't go to the bedroom very often anyway.