Is a house for a total volume of 400k still possible at all?

Give up the basement, then it will become real. However, ask yourself what will happen to the property if it is "verhökert." No one has €22,000 to give away.

Ok thanks for your assessments. That means with a basement another 50k would have to be added? The plot is okay. It is basically a friendly price from acquaintances of ours. Therefore actually the motivation to possibly build after all since it is a nice opportunity. Besides, there is also a certain value in return.

Basement rather 70k. Without basement it will probably work.

Basements require *in addition* to the mentioned 70k also a bit of risk buffer.

The risk decreases if you have a soil survey or get one from the neighbor. Cost risks include, for example, Z1 contaminated ground, high groundwater. Building without a basement is more financially predictable.

So we had an offer with and without a basement and the difference was 55,000.
However, there are also about 10k more for earthworks.

Phew, it's really shocking that nowadays you can't get a "small" house with a basement even with 400k.