Soil survey and land surveying during the planning of an extension

Hello everyone,

I need your expertise. In the context of a planned extension to an existing single-family house, is a soil survey and a building plot survey necessary?

When the single-family house was originally built, the owner did not have a soil survey conducted.

What do you recommend? Is it absolutely necessary or advisable for self-protection? Or can it be omitted under these circumstances?

I look forward to your responses. Thank you very much and best regards.

Apart from the fact that it may be mandatory: this is usually the basis for all static calculations and therefore also liability relevant. Honestly: I wouldn't save money there

We had to have the property surveyed for our extension because there was no official plan of our [Grundstück]. Our neighbor still had his from 1938, and the office reluctantly had to accept it.

Always have a soil survey when building. You should never save money in the wrong place. Because what you save on the soil survey, you will later invest twice as much in a overdimensioned foundation or in repairing settlement cracks.