Basement planning prefab house - outsource? What to consider?

The difference is not massive or timber frame, the difference is the target group, the size of the company, etc.

For example, you can buy a shell house at Allkauf Haus, you can order house XY without floor coverings and painting work at Town & Country, you can have your house individually planned and built by the carpenter Hans Müller and specify that Max does the sanitary work and Kurt does the basement. Then you have large timber frame builders who build any freely planned house for you, but you have to take their basement and their sanitary system.

What advantages do I have in terms of process, flexibility, and own contribution if I build a solid house ready for painting compared to a prefabricated timber frame building?

Solid houses are simply unbeatable in flexibility. For example, we wanted a room with a height of 3.50 m. Out of all the prefabricated house companies we inquired, only one company could offer that at all. And not exactly cheaply. The solid shell builder didn't care much. He just laid a few more rows of bricks and the thing was done, exactly according to our wishes.

Things that bother me:

The architect has no knowledge of your property, it is included, but after the application I can first look for another architect who checks and plans the drainage, pipes, etc. The prefabricated house companies are too far away from the action and somehow there is no holistic planning.
Therefore, also no creativity from the architects, something is simply built and done... Whether it fits the property, no one really knows at first. Costs afterwards may be significantly higher... Depending on whether everything works or not.
With all the prefabricated house companies I already have in closer consideration, I should best take everything from them... Otherwise, they immediately come around with the warranty thing etc. Then there are only the things available in the sampling center. I cannot choose anything anywhere, at no regional company for example (no idea if this is different regionally with a solid builder? They may also have their partners?)

It bothers me that I have no leeway at all and am nailed down to everything.
But I also don’t want to plan my house completely myself and coordinate and plan every trade myself.
I want more say and the things that I might want to decide myself, to plan myself.
What if I don’t like the windows that are in the sampling center? What if the bathtubs are bad and the extra costs for the bathtubs they have are enormously high?

As soon as I want to change something about the floor plan at a prefabricated house, everything immediately costs extra. An individual planning is not really possible.

But I am somehow also afraid that this will all be much more expensive with regional companies? That then my solid house with similar planning is simply 10-20% more expensive?

I am somehow still extremely undecided and dissatisfied with how things are going so far with the prefabricated house companies.

Are such things maybe more flexible with smaller regional companies and might I even come out cheaper as a result?

Do such things possibly run more flexibly with smaller regional companies and could I perhaps end up even cheaper because of that?

For us: absolutely yes! Of course, our general contractor also has their partners. But the sampling was then done at a regional building center where they really have everything. We could choose whatever we wanted. We knew for everything which prices our general contractor was calculating with. And there, according to our wishes, some things were a bit more expensive for us and some a little cheaper. But all that was properly balanced out. In the end, for 2 bathrooms completely with tiles, walk-in showers, a bathtub, two sinks, and all fittings, we had an extra cost under 500 euros. Very fair.

I think there are corresponding clauses in the contracts that prevent Glatthaar from building basements for Hanse houses bypassing Hanse.

I can confirm that. At least in our configuration.

For us: absolutely yes! Sure, our general contractor also has his partners. But the sample selection took place in a regional building center where they really have everything. We could choose whatever we wanted. We knew for everything which prices our general contractor was calculating with. And then, for us - exactly according to our wishes - some things were a bit more expensive and some a little cheaper. But it was all properly offset. So in the end, for 2 bathrooms complete with tiles, walk-in showers, a bathtub, two sinks and all fixtures, we had an additional cost of under 500 euros. Very fair.

How are the houses priced compared to prefabricated timber frame houses?

Is value also placed on KfW standards in solid construction? What does it look like there? What notable differences can you mention?