Land purchase, soil assessment report available, is a second assessment necessary?

Hello,

we are about to buy one of 3 developed plots, the seller is a real estate company that has carried out 2 boreholes on each of the 3 plots, diagonally across an "imagined" base area. Since there is no development plan for these plots, only a positive preliminary building permit exists, we have free rein as to where the future house should be located.

The 6 boreholes on the 3 plots hardly differ from each other (no groundwater, mainly silt, medium sand, and clay), however, our house would be located 10 meters away from the 2 boreholes made on our plot. Do we necessarily have to have a second soil survey carried out for our safety, which lies exactly under our planned foundation slab? (Actually, even with 4 boreholes at all corners, you can't know what the ground in the middle is like, right?)

We want to build with an architect, he would have to advise us and be obliged to do so if necessary, unless he does not want to be liable for consequential damages?

If the soil at the location differs from the other boreholes and therefore more excavation and filling is required, it is clear to me that construction costs will increase, but the excavator would notice this at the latest and thus avoid consequential damage to the house?

To what extent does a plate pressure test provide additional security for the building?

Thank you in advance..

Some need belts and suspenders. I would save myself the second expert opinion. Reasons: 1) The prepared expert opinion smooths out uniform soil structures on all properties. The probability is therefore very high that this is also the case in your building area. 2) The expert opinion states what is, but does not save a cent of groundwork. So if, against expectations, there is a surprise, it will be there with or without an expert opinion and will cost the same anyway. Karsten

Some need belts and suspenders. I would save myself the second expert report. Reasons: 1) The created report smooths out even ground structures on all properties. The probability is therefore very high that it is the same in your building plot. 2) The report states what is, but does not save a cent on earthworks. So if, contrary to expectations, there is one surprise, then it is there with or without a report and costs the same anyway.. Karsten

Thank you, so the only thing it brings me is earlier better certainty about the costs?

The excavation contractor will then see from the subsoil what he has to do to build a load-bearing slab anyway? He is also ultimately responsible for the foundation of the house..?

Well, theoretically, with a house plan that includes a basement, there is still the option that the basement becomes exorbitantly expensive due to the soil, and after the survey, you would still have time for replanning (or extending the financing).

Equally important are possibly statements about infiltration capacity. In our case, a preliminary examination for geothermal system design is done during the drilling for the survey.

All of these are things that are neither indispensable nor should give you reason to commission another survey.