Decision aid for choosing the construction company

I can only absolutely agree with you and also understand the various uncertainties. However, meaningful behaviors have emerged here in the forum, and that includes presenting your own situation as openly as possible from the beginning so that you don’t plan castles in the air; especially when, like the OP, you openly admit to being an amateur. Unfortunately, we learn on page 21 that there is already a "finished floor plan," which the OP does not show, but instead babbles about SmartGrid (what kind of nonsense is that anyway?). Committed people have given their time to design such a questionnaire; this is still simply ignored by the OP, even after page 22 in the thread, while we hear more complaining from his side. How could the floor plan etc. already be "fixed" (quote from the OP) when the construction company is not even known yet, so the project has not been seen by anyone from a building law or technical perspective, let alone financing. He must still be in dreamland, which is part of it. But one should be aware of that and allow enough time for it. If you then also put yourself under time pressure, the likelihood of falling into a marketing trap is quite high; THAT is exactly what they want to tell him here, which the OP, however, perceives as mere grumbling. Whistleblowing is a very bad advisor when building, that's no wisdom. If the OP were to answer all the responses already received from forum participants, he would be much further along instead of already discussing the facade of the garden house in another thread. Every forum participant wants to be taken seriously and deserves, in my opinion, a reply; otherwise, the OP should simply build his thing and be done with it.

In my experience so far, which is somewhat theoretical, some prefabricated house manufacturers can indeed "build individually as you want," at least in the broadest sense. Just enough so that it is perfectly sufficient for the majority of builders.

Sure, but they will probably charge you a pretty penny for that.
With the Golf, you can also choose and order all kinds of engine / equipment variants.
However, which manufacturer supplies the brakes, transmission, injection system, etc., you have no influence on.
Regards, Olli

Sure, but that will probably cost them quite a bit.
With the Golf, you can also choose and order all kinds of engine / equipment variants.
However, you have no influence on which manufacturer supplies the brakes, transmission, injection system, etc.
Regards, Olli

As soon as OP has something concrete in hand, he can inquire there as well, then he will get certainty about it. But first, there are other things to do.

In the parallel thread, the completed questionnaire, property, and possibly [Grundriss] now appear.

in the parallel thread the completed questionnaire, property and possibly floor plan are now appearing

I saw it.... somewhat "filled out", rest nowhere to be seen just like the answers to all previous questions. A little bit here a little bit there.....

Yes, unfortunately, my two questions were not answered here either...