Sealing basement wall - ring drainage with drainage pump?

uh... there isn't one. :) the builder (turnkey) says he has already built in the area and doesn't need one...

What nonsense,... Maybe there's a water vein running directly under your property at a depth of 2.5 meters? The risk for a €1,500 cost saving,... A waterproof shell only makes sense with watertight windows and light shafts that are themselves watertight and therefore require an additional drainage system. That gets pretty expensive for an office (probably with large windows planned).

My building surveyor recommends a white tank (load case 6). However, my construction company considers that completely exaggerated. Can you give me a recommendation on how to seal a basement sensibly but not excessively? I am not aware that the ground is particularly wet.

If you don't know what the ground condition is like, I am on the side of the building savings contract.

We need neither drainage nor any other fancy stuff. The basement is dry.

If your construction company is already bringing this up, the ground apparently is not quite optimal....