You said 1m2 of bare basement is more expensive than 1m2 of high-quality living space. And I gave a current counterexample where 1m2 of bare WU basement was about as expensive as 0.5 to 0.7m2 of high-quality living space on the ground floor and attic. That doesn’t necessarily mean you can generalize from me to the public. I was also told that basements are more expensive than above-ground living space, but that surprisingly didn’t hold true in the calculation.
I’m still glad not to have a basement under the water because of the groundwater risk.
That is actually true – it was the same with us. It always depends on the building area. Depending on that, a basement isn’t necessarily much more expensive than enlarging the above-ground living space... That can also make a basement sensible for a larger flat plot. Of course, it’s also a matter of personal preference... I would never have built without a basement.
But well, nonetheless, I also think that you probably won’t be happy without a basement, judging by your comments. So, with 400k all in all, you will never be able to build a single-family house of that size. At the beginning, we also looked into prefabricated houses – exactly the same structure as the house from Bien-Zenker, which you posted here.
All in all, with a basement, we ended up at exactly 400k. We might have been able to reduce that to 380k. Without a basement, you might manage about 340k. If you then scale down drastically (no garage, etc.), you might get it to 280-300k. But honestly... you first have to be happy with that, and I really doubt it :D
For us it was very clear: if a house → then properly! Of course, you always keep costs as the number one priority in mind, but we wouldn’t want to give up many things... For us, it would also clearly be the basement. I actually think, if we played with this budget with the thoughts you have, we wouldn’t build a house.
You really have to be sure about this project and should feel comfortable afterward. If you can manage with a 280k house at 120m² without your actually demanded “features” and you think you can live with that, then go 4 it! Otherwise, that probably won’t work for now :(