Building inspection before purchase not possible – too risky?

The question is, what do you (still) want to achieve with the soil survey when there is already a house on it?! My opinion: You don't always have to use the red thread if the path is caught elsewhere :cool: In this sense: good luck with the land purchase :D

Our soil survey, for example, stated how high the groundwater is and from which rock layers the soil consists. This can require certain measures that were not known or simply not implemented 100 years ago.

The greatest risk here is that a basement becomes too expensive according to modern standards and one then simply decides against it.

The biggest risk here is that a basement becomes too expensive according to modern standards and then people simply forgo it.

The ground might also not be stable enough for today's requirements. Then a replacement would be necessary. It was like that for us. Our old house was also there, but for the new house, a part had to be replaced. It cost us about 5000 euros in 2021. If the ground to be replaced is somehow contaminated, it will also be more expensive.

In addition to what has already been said, I would also add that a soil survey can provide information about the landfill class, i.e., possibly higher fees for the disposal of additional excavated soil. Although there obviously is already a pit.

A static calculation is also made in advance today, and the structural engineer needs soil parameters to calculate, which only the soil survey can provide. But basically, I do not consider it too risky if the survey is only done after the dismantling. But keep in mind that everything takes some time.

A static analysis is also prepared beforehand today, and the structural engineer needs soil parameters for calculations that only the soil report can provide.

Yes, the theoretician needs it for his calculation model. Nevertheless, for the practical question: "Does this subsoil support a house?" the existing building itself is a kind of positive soil suitability report. One can hardly seriously consider (non-existent or minimal) settlement cracks to be less meaningful than bore cores on the laboratory shelf. It is once again just a theoretician who wants something to play with. Of course, the existing building proves suitability only under two assumptions: that the new house is not heavier than the old one, and that it is placed on the ground of the cleared building pit, neither deeper nor higher. I would like to point out – as someone probably also strongly inclined toward theory – that when adding a storey one does not first demolish the house to investigate the ground underneath; even though the house becomes heavier in the process. Which, by the way, also applies to the not uncommon case where someone replaces a load-bearing wall with a steel beam: the structural engineer is only asked whether the house above continues to hold – not whether it continues to be supported by the subsoil. One can push everything to extremes and overdo it.