Which house construction "provider" to choose?

The architect's fee must not be underestimated. For large prefabricated house companies, it amounts to €4,000-6,000, while for small companies and GUs, it can be €30,000-50,000, 10-15% of the construction cost, so one should consider that.

In prefabricated house companies, the fee is included in the catalog house; how the costs add up in the end is irrelevant.

Exactly, the architectural service is always included, whether you receive a separate receipt for it or not.

I had about €4800 architect's fee. The amount was fixed beforehand. In individual planning, it is difficult to estimate the costs; €30,000-50,000 are roughly the same. Changing this or that costs

Yes, but as written, you can't compare that because the planning costs in GU flow in elsewhere. €4800 is a weekly fee; no one could or would plan a house for free with that. With a catalog house, it's of course different; you just have to adjust the GP a bit and that's it. But theoretically, architects also offer something like that.