Costs of soil assessment / geotechnical investigations

It was not done in the past. Today it is done since the graduates have taken over the construction sites. In the past, people said, here it is clayey, or here it is sandy, etc., and then built accordingly; you could see when digging the pit what came to light and reacted accordingly. Today, there are often reports on the property on top, especially in new development areas. Or you order it for a good 1000,- from geologists or say, as in the past, let's see. K.

For the various providers we visited, a soil survey is a mandatory requirement. Google soil survey + geologists. We ordered it online and were very satisfied: 2 drillings with laboratory analysis cost about €1000. The civil engineer was friendly, competent, and sent us a very comprehensive report.

Makes sense for the geotechnical report, so yes.

In the soil analysis, I think soil/excavation is "collected" at some diagonal endpoints, mixed together, and analyzed.

Soil analysis and geotechnical report are two different things. You need the second one for the structural engineering and ground treatment. The first one for the landfill.

Do I need both for building the house? So analysis + report? Or is the geotechnical report enough?!

Thanks in advance

You need the soil analysis according to [LAGA] if you have something to dispose of.

The plot is 800 sqm and a 120 sqm bungalow is planned on it. I don’t think the excavation will fit entirely on the plot... So some of it will probably have to go to the landfill. And for that I then need a permit to show that the soil is basically acceptable for the landfill?!

Yes and no. Not here. Here the landfill accepts it as is. They simply believe that it is uncontaminated stuff. In industrially more polluted areas, it might look different.