Basement planning prefab house - outsource? What to consider?

But if I really don’t want to do much by myself, actually only want the stage of painter-ready finishing, does the regional concrete construction company still have a great advantage or does it still differ in this regard?

I already said that: a "prefabricated house manufacturer" is not a wrong general contractor for you, just not the only possible one. In my opinion, you can consider all general contractors regardless of the wall construction method.

I might also want to be able to say: Your windows are crap, I’ll get a specialist shop myself and have them installed.

As long as PVC windows are generally good enough for a builder – to which, as a former aluminum window manufacturer and MAD reader, I *retch, gag* say no – then the differences between suppliers Müller, Meier, and Schulze are marginal. At least regarding the products themselves – the installation shows significantly greater quality differences.

Here in Baden-Württemberg, especially in our area, there are really good construction companies who together probably make up 80% of the buildings in the surrounding new development areas.

Yes, then take one of those. They wouldn’t get so much positive feedback from customers if most of their stuff first had to be re-engineered to reach a decent quality standard. They must be hitting satisfaction (also in terms of taste) so well that it really fits for a majority.

Take a small one without a large sample center - wall structure doesn't matter. The one without a large sample center has its regular craftsmen and accesses their entire range. Although they will also tell you, like, the technology won't work in that house. With our general contractor, almost all trades come from within a 30 km radius and would probably have worked on the house even with individual contracts. Although I never want to deal too closely with whether tile adhesive xyz is better than abc. You just have to trust that a high-quality general contractor doesn’t install rubbish.

Prefabricated house because I don’t feel like coordinating a bunch of trades and waiting 2 years for my house because the planning is simply way too complicated and time-consuming.

I also don’t want to constantly monitor the construction and spend weeks on the building site.

What bothers me is that I have no leeway and am nailed down on everything. But I also don’t want to plan my house completely by myself and schedule and plan every trade by myself. I want more say and want to plan the things I might want to decide myself.

Definitely, that wasn’t meant like that. Ideally, I would schedule, plan, and tender everything myself completely independently.

I see tons of contradictions from you here: I don’t want to plan myself, I want to plan myself. I don’t want to plan and coordinate myself, I want to plan and coordinate myself...

What if I don’t like the windows that are in the sample center?

Do you have any knowledge about windows that you might not like?

Finish stage ready for painting,

A shell house means: doing a lot yourself, so doing the finishing yourself.

Your windows are crap, I’ll get them myself from a specialized store and have them installed. Is that also considered own contribution?

Can you judge windows that are nonsense?

I find it hard to trust what they tell me.

Well, then...

In short: I can’t build any trust here..

Then you shouldn’t build.

The proximity to the project is simply lacking. The architect doesn’t set foot on the site even once and can’t check what’s going on.. It’s somehow not a holistic project. It’s somehow for people who don’t want to have anything to do with everything and say: Just do it.. Isn’t it so? I somehow have a very very hard time with it. Everyone also tells me some other nonsense.

Somehow it seems to me like you’re just talking nonsense. You have no clue about anything but talk about wanting to evaluate everything, thinking you should know better, others are feeding you nonsense. If you think no company is legit, then nothing will come of you and a house.

Here in BaWü especially in our area, there are really good construction companies that surely account for about 80% of the buildings in the surrounding new development areas.

Then just visit them.