Building ground not sufficiently load-bearing - is soil replacement sufficient?

Here we are. We were offered a pile foundation as an option. We then carried out a soil replacement + embankment. In other words, we are easily 3 meters away from the groundwater. But that won't help you much now, since we surely have different soil conditions than you.

In our area, predominantly pile foundations were carried out. Our townhouses, however, were built with basements. Permanent groundwater lowering was necessary during the construction period.

For €100,000, however, you get the WU basement (necessary) with residential quality in at least 50% of the area. This must, of course, be taken into account in the floor plan, so that you don't suddenly add another 75 sqm on top of the desired 150 sqm. The upper floor must be correspondingly smaller, then the basement will cost significantly less than €100K extra. In contrast, there is the expensive pile foundation (I once read €30-40K), whose costs are simply gone.

Here near us there is a construction area where all houses have pile foundations. During a house viewing, a family told us that they paid 80,000 euros just for the pile foundation (without a basement), which seems very much to me. A WU basement including water control should also cost around 80,000 euros here, so it’s not exactly cheap either.

Best regards
Sabine