Cohesive soil. Is soil replacement for the foundation sensible?

Our building plot has cohesive soil (silt, clay content, poorly water-permeable). Such cohesive soil is also suitable for house construction but tends to settle over the long term. Is soil replacement advisable in addition to drainage? And at what depth? Or is a 30 cm capillary-breaking layer of gravel under the slab sufficient?

You can find the information in your soil report. It states which soil is present at which depth.

It is similar with us, at least 80 cm of gravel is being laid (currently in progress). The soil survey should include a foundation recommendation.

The foundation recommendation provides for a statically reinforced slab and a capillary-breaking layer of at least 30 cm beneath the slab. Nothing more. It seems a bit meager to me. I would rather spend a few thousand euros and possibly carry out soil replacement. But does it make sense?

When the geologists say, that’s how it goes, that’s how it goes....or do you have too much money? I’ll give you my account....