Single-family house made of precast concrete parts?

I hardly think anyone does it because... "das haben wir schon immer so gemacht".

It is certainly not inherently wrong as an argument (you shouldn't necessarily do something the construction company has never done before...), but in my opinion, one should not write off reinforced concrete or prefabricated parts so generally, because I believe that with appropriate planning, the price differences are no longer decisive.

I hardly believe anyone does it because... "we've always done it this way".

That is certainly not per se a wrong argument (one should not necessarily do something the construction company has never done before...), but in my opinion, one should not dismiss reinforced concrete or precast elements so generally, because I believe with appropriate planning the price differences are no longer decisive.

I see it differently.

With the shell construction company that built our shell three years ago, we discussed many options at the time. It is not a small company and we know the owner very well. They do a lot of multi-story residential construction, so also general shell construction (commercial as well). Our basement was built with precast elements. That was a deal we made with him so that it wouldn’t be more expensive for us afterward, but it would be normal with in-situ concrete construction. The time factor was important to him. For the ground floor and upper floor we were open regarding materials and structurally we needed a concrete wall and a few concrete elements. Therefore, we also talked about alternatives, all in concrete, etc. His clear statement was that it only makes economic sense for larger projects (structural engineering etc.) And also here, not to mention the planning effort. It may be different if you are a "prefabricated house company" with standard floor plans where you reduce the planning effort through "series production". With individual floor plans and every time technology, sanitary, heating, etc. must be precisely planned before (!) the shell construction and every time with different craftsmen.

If it were a time or margin gain for construction companies to build more with concrete, it would also catch on, whether or not it has always been done that way.

As already mentioned, I do not believe that building with concrete in the single-family house sector is cheaper, but I do believe that the price difference is much smaller than what is usually assumed.

However, it is an absolute mystery to me that nowadays not everything in the single-family house sector is planned cross-trade as BIM – so much trouble and construction site problems can (potentially at least) be avoided with it. Well, the industry is simply slow – but once this has established itself (10, 20 years?), the fear of preliminary planning will surely also be somewhat alleviated.