Approximate ancillary construction costs - gap in financing

Civil engineering/earthworks. They have a KVA of about 22k there which is still without a soil survey and refers to the planned dimensions of the house.

You will only get a reliable calculation once you have had a soil survey done. So you should commission this.

Outdoor facilities: Unfortunately, I also don't know what one should estimate per sqm for paving of parking spaces/entrance area or... terraces (of course highly dependent on material), since we would also quite like to have it done directly.

Reference values have already been given here in the forum. Including everything, I estimate about 60 Euro / sqm for simple paving, rather 100 Euro / sqm for terrace slabs. More rather than less.

That's the whole topic of house connection costs, I don't know if there can still be a really big surprise there.

The only help is to inquire individually with the respective suppliers. In case of doubt, the municipality/city can name you the basic supplier.

And the basic supplier will tell you the network operator.

And the basic supplier will tell you the network operator.

That's right, you need the network operator, not the basic supplier. I had mixed that up.
Usually, the city/town can also tell you the network operator directly.

Who coordinates these things later, that is, when who has to do what where? Is it handled by the house builder, civil engineer, architect?

Depends on what is stated in the construction contract. In case of doubt, you. And for electricity in NRW, it is 99% a subsidiary of RWE, probably Westnetz. Kabel and telephone belong to Telekom and Unitymedia, where you will find information under the keyword [Bauherrenberatung].