Drainage planning for the protection of foundations with perimeter insulation?

Hello,

we have a house without a basement, but with very clayey soil, the water drains very slowly. We now want to build a drainage system to protect the strip foundations and avoid "overflowing" water. The strip foundations are about 100cm below the top edge of the floor slab. We will also raise the soil to this height.

Attached is a picture with the heights I have in mind.

Further questions that remain:
- Is perimeter insulation around the foundations additionally useful?
- If yes, does it have to be tightly coated with bitumen paint?
- Can I let the rain gutters drain directly into the drainage system?

Drainage water must not be discharged as rainwater in every municipality.

At [und] helped to simply mix the upper sandy soil with the lower, heavily compacted clay layer (excavator bucket).

Thank you in advance for the response. We definitely want to install a drainage. Is the depth okay or should it be deeper?

Is the depth okay or should it be deeper?

Isn't that a question for an architect or construction company? It is quite special and requires an expert, everything else is not reliable.