Earthworks

Well spotted ;-)

It is like this: The offer from Erdarbeiter 1 requires supplying the soil themselves, meaning we have to pay for it as well. Therefore, he apparently just took as little soil as possible so that it wouldn't get too expensive. However, that's not enough for the house, driveway, carport, and terrace... In the other offer with the 300 m³, we can get the soil for free; only labor hours and costs for pickup and filling apply.

How does it work with you? When you have filled the soil accordingly, what happens in the areas where no elevation took place? Topsoil?

We have 150 m³ topsoil which we will distribute over the remaining 800 sqm area. Think about retaining walls, if necessary. Ask about that if you need any :)

Retaining walls?

when piling up, if you have direct neighbors, you must ensure that nothing shifts to the neighbor over the years.

That can certainly still be done afterward, right? We don't know our neighbors yet, and they would have to build roughly at our level, as is exactly described in the development plan.

I appreciate that it can also be done later, but I think the one who builds the wall first pays for it :) In any case, you need to clarify what the regulations are. It might also be that you don't need one at all if he builds to the same height. ...