New building with basement | WU concrete plus ring drainage

The rainwater is certainly more polluted than the water that comes from the drainage.

Since we really have no idea, we are most likely the perfect "cash cow"!!

The contractor wants to sell you the drainage shaft and the cistern? Am I right. "The contractor only wants your best."

No, it’s not that bad! :) We initially talked about a cistern but he said it would probably be cheaper if we outsource it and have it installed by the landscaper. Only later in the planning did we decide on a basement. What annoys me is that this option was not brought up again if it is one. However, I need to clarify whether the excess water from the cistern can be discharged into the sewer system. Since the water from the roof can be fed in, it should also be possible with the cistern.

Does the contractor already have the order?

However, it makes sense to build the cistern if you are building with a basement. Without a basement, it is certainly more the job of the garden landscaper.

Does the contractor already have the order?

No, no order has been awarded yet.
We are planning turnkey and have now reached the point where we have to decide what to do. Basically, we were waiting for the soil survey to decide on the execution of the basement.

Therefore, I am very thankful for your input! I will now approach the contractor with the white tank and bring the cistern into the discussion again. Certainly the cheapest option!

Just suggest my post #11 to the entrepreneur. That saves him / you a lot.