Is it possible to determine the eligible costs based on a rough estimate?

The architect can also charge less, for us it is a total of about 7%.

The architect can also charge less, for us it is around 7% in total.

Is that just the architect? My 10..11% referred to all engineering services (e.g. also soil surveys, surveyors, etc.)

Only the architect level 1-9.

Is that just architect? My 10..11% referred to all engineering services (e.g. also soil survey, surveyor, etc.)

10-11% for all service phases including structural analysis, soil, energy and surveying is quite a bargain! Is the guy always that cheap or did he urgently need the contract?
Take a HOAI calculator and see what minimum rate comes out in fee zone 3 for your costs ...

That is not correct. There are a few local construction companies here that exclusively plan individually and employ their own architect or planner. Should I therefore expect that approximately €45k-€60k are hidden in the house price, or are planning costs of this amount itemized? Are services such as structural analysis, soil survey, etc. not usually included in the service phases or in the 11%?

10-11% for all service phases including structural engineering, soil, energy, and surveying is quite a bargain! Is the guy always that cheap or did he urgently need the contract?
Take a HOAI calculator and see what minimum fee you get for your costs in fee zone 3 ...

I am also very satisfied with the price. In the end, it was about ~45k EURO. We had to save somewhere after all. The rest was/ is expensive enough..

Regards, Steffen

PS: The guy is booked out for the next 2 years and is "building" 7 houses alone on our street! Most of them are quite a bit bigger and more expensive than ours..