WU-Keller - What additional costs are to be expected?

If you build without your own expertise, this is exactly what you get. Botched work. A WW must be contractually agreed upon (which is obviously not ensured here), well planned and carefully monitored, as it is prone to damage. It would be interesting to know what you need a gravel drainage layer for, presumably because it sounds good and you can charge extra for it. The construction will certainly be exciting overall and significantly more expensive plus botched work.

I find the surcharge compared to the basement price of 100,000 euros quite realistic. Thicker floor slab, more steel, etc. that just costs. Our acquaintance also had to build a white tank (but that was in 2006) and already had a surcharge of 30,000 euros back then.

Best regards
Sabine

I have an acquaintance who built two years ago and had an extra cost of 3,000 euros, I wonder what that was due to........