Soil assessment report - How should the report be evaluated?

Hello, hopefully I have now used the correct category in the forum.

For our construction project, we now have a soil report for the building area. I would be interested in your assessment of excerpts from the general evaluation of the buildability.

The builder has already read the document. From his point of view, there are no major problems. Only the topsoil, which has to be removed, is somewhat more than expected and the depth of the shrinkage apron still needs to be checked. On the other hand, of course, he also wants to proceed to contract conclusion.

Excerpt from the report:

“The existing topsoil must be excavated within the influence area of the construction and, if necessary, replaced with replacement soil. […] The loess clay underlying the topsoil is to be classified as sufficiently load-bearing for usual loads from one- to two-story buildings. […] Due to generally high plasticity, the weathered clay, which was detected at depths between approx. 0.95 m and 2.00 m below the current ground surface, can shrink or swell when the water content changes, so that a basement is generally recommended. […] For buildings without basements, it must be checked on a case-by-case basis, depending on the elevation of the building foundation and the depth of the shrinkage-sensitive clay, whether and to what depth a so-called shrinkage apron must be arranged. As a rule, no trees or plants with high water demand should be planted within the influence area of the building foundation, as these can draw water from the clay soil during dry periods. As a result, settlements and sagging of the building can occur.”

Does anyone here have experience with such reports? We do not want to build a basement. Should I now fear that the mentioned clay will eventually swell and cause the house to fall apart? I also find the wording that trees near the house can cause damage frightening.

I am reading such a document for the first time and am not sure how to assess some of the wording. Of course, the expert has to present all possible scenarios for liability reasons. Do I now have to worry about my small single-family house?

Best regards

As a small addition (editing is no longer possible): According to the soil sample, below the topsoil, which is to be removed, there is initially 'silt, very weakly clayey, fine sandy, UL, stiff to semi-solid, light brown' and then 'clay, silt lenses, silty, TM, TA, semi-solid, gray-beige' followed by 'clay, TA, firm, gray'.

How deep is this clay layer? Does it start at 0.95 to 2m and extend how far?

I believe we do not have an expert for this in the forum.

In general, I am in favor of a soil survey and in this case, it should be mandatory. The recommendation for a basement suggests to me expensive remedial measures if no basement is built.

I would have a soil survey done on the specific site before purchase to estimate the earthworks.

Is this really a developer? Who bears the risk for earthworks?

I'm not a geologist, but anyone who can read will see it. It is more difficult building ground. Please discuss carefully with the BU, the civil engineering department, what can be done there and how. Or don't buy this land. Karsten

The specific drillings near the construction project (in the mining area) yielded the following result:



Of course, the building ground must be analyzed again in detail.

The developer said we have to budget about €10k for the work done (about 100% more than originally planned). If all the topsoil is removed and a sand-gravel bed is built on it, can I assume that my house will have sufficient support?

Actually, our project was in the final phase. According to the report, construction is possible. Am I now reading too much into the clay/silt?