We have not yet decided on a construction method and still have 2 years until the start of construction. We are still saying that only the shell and sanitary work will be outsourced. The rest will be done entirely by ourselves. It is not about building a house quickly but efficiently. The energy standard should reach 40 plus.
Then most of the large timber frame companies drop out. Many do not offer shell houses. Actually, I can only think of one and we are not convinced by their houses.
You need a company that operates in the field of Kfw 40 passive houses.
In which area of Bavaria are you?
Bavarian Forest... Upper Palatinate. Yes, basically only a prefab house company could assure us of the expandability, and it will probably not fit into our budget, as you already say haydee
I can recommend Wir Leben Haus to you. We built with them. A few places away someone built with a lot of own effort with the company. He was very satisfied. Whether they always do that, no idea. Check out the local carpenters and construction companies. Ask your plumber for tips.