Even though the thread is a bit older, I would like to add something because we built with Massa Haus...
Hello,
Massa Haus needs a trailer hitch, as the builder has to pick up the expansion packages himself at the hardware store, in my opinion Praktiker.
That is not true. We had all the ordered expansion packages (insulation, drywall, heating, and sanitation) delivered to the house. Without extra charge. Of course, we had to carry everything inside ourselves, but we did not need a trailer hitch!
I see the prefabricated house as a all-round carefree package. I have not regretted it so far.
Then you certainly did not have Massa Haus. It was certainly not carefree for us. But you grow with your tasks, and today I am glad to have taken exactly that path. From the date of setting up the foundation to moving in was 3 1/2 months, except for screed, electrical, and tiling work, everything was done by ourselves.