Soil investigation: relatively deep soil replacement necessary

Hello everyone,

My wife and I have been allocated a plot of land in a new development area through a lottery, and we are now considering whether we should buy it. While reading through the geotechnical survey (see pictures), we got the impression that the soil conditions are rather poor, and we are now leaning towards not taking the plot. According to the report, the load-bearing terrace sediments are only found at a depth of 4.30m, which necessitates soil replacement. The RKS 24 mentioned in the report is located in the immediate vicinity of our plot.

Therefore, I would be interested in your assessments of the report. In particular, what additional costs for the foundation compared to a "problem-free" soil can be expected. We intend to build with a basement.

Many thanks and best regards

Organic soils up to 4.3 m is unusual to my knowledge. What was there? What do the other boreholes say?

The expert also suggests using a load-bearing floor slab for economic reasons.

Since you are building with a basement, I don't see a big problem with you. The soil has to be removed anyway, then a bit of gravel added + floor slab.

Thank you very much for the response! The area has been used for agriculture so far. I am not sure where the 4.30m of organic soil come from; perhaps there was once a side arm of the Rhine flowing there. We will reconsider the purchase of the property.

Hi,
if you are building with a basement, you have to excavate anyway to a depth of 3.3-3.6 m. Sure, the last extra meter costs more money, but if everything else fits, I wouldn’t be deterred by that.

Best regards,

Andreas