Earthworks and shell construction, who bears the warranties?

Thank you for the answers, the soil survey has already been carried out and the company that is carrying out the earthworks needs it.

For the earthworks contractor, the report is only interesting in terms of which soil types he would have to work with; he has no influence on the structural engineering of the building.

Thank you again for the response. I have one more question: Which insurances must one have, or would it be better to have, before the construction phase begins?

a construction insurance would be an option, maybe ask the insurance agent you trust

Builder's liability insurance. Shell construction fire. Possibly construction completion insurance. The latter can be omitted if there's some risk. It pays out in very specific cases. Example: Walls and roof truss are standing. It's paid for. So mine. A tornado comes and everything is destroyed. Now this insurance pays for the reconstruction. Shell construction fire is free if the finished house is insured with the chosen company. Karsten