Where can one get advice on purchasing land or building ground surveys?

Dear members,

we would like to purchase a plot of land in the south of Saxony-Anhalt. There is quite a bit to consider and a lot of reading to do. I have studied several books and picked out important points. As far as I can tell, I have taken everything into account that needs to be considered. Just recently, we had a soil survey conducted. However, this is exactly the point where I am uncertain. We already have groundwater or interstitial water after just 1 meter. In addition, the first 1-2 soil layers (up to about 1 meter) are not particularly load-bearing and are loose. Since I am generally more of the planning type, I would like to estimate how much more (percentage-wise) the foundation slab will cost because of this and whether the additional financial costs would devalue the plot so much that it would be advisable not to buy it.

Which consultant should I consult who can give me clear statements about whether the waterlogging and soil conditions are so serious that laying a foundation slab would involve too high an effort/costs too much?

Architect, civil engineer, consumer advice center....???

Since we want to purchase the plot FIRST and only really start building a year later, we have not yet chosen an architect/prefabricated house company AND I do not want to commit myself yet.

So I would question the geologist who prepared the soil report for me!

Question to the geologist:

According to the report, the soil is not optimal for construction. Can you estimate by what percentage the construction of a slab would be more expensive than in an optimal/normal case (10%, 50%, 100%??).

I received this answer:

The additional costs for more extensive soil replacement vary significantly based on experience. I would recommend comparing several quotes for the earthworks.

So this does not really help me in this case...

Hello,

We recently had a geotechnical survey carried out. However, I am uncertain exactly at this point. We already have groundwater or perched water at 1m depth. In addition, the first 1-2 soil layers (up to about 1m) are not particularly load-bearing and are loose. Since I am generally more the planning type, I would like to estimate how much more (in percentage) the foundation slab will cost as a result and whether the additional financial costs would devalue the property so much that buying it would be inadvisable.

Interesting formulation: it is not the foundation slab itself that becomes "only" more expensive, but the foundation preparation costs increase due to soil replacement. It also depends on whether you want to build with or without a basement.

Which consultant should I contact who can give me clear statements about whether the water infiltration and soil condition are so severe that laying a foundation slab involves too high financial effort / becomes much too expensive? Architect, structural engineer, consumer advice center....???

The commissioned geotechnical engineer – but not with the question about the additional costs, rather about a targeted foundation recommendation; this should actually be described on the last pages of the report. With this recommendation, an extract from the land register of the property, and the basic data of the future construction, you go to a trusted deep foundation contractor and ask him to provide an offer regarding earthworks "before" the start of construction; i.e., the preparation of the building plot. Until then, of course, you should know whether to build with or without a basement.

Best regards from the Rhineland