How expensive is a turnkey prefabricated house with a granny flat?

Apart from that, prices have been moving away from 2000€/sqm at the latest since the raw material shortage in spring. Additionally, a granny flat is not necessarily equivalent to simple living space. You also need a bathroom, a kitchen, and possibly a room for the respective house connections. The partition walls have to be built differently, etc. All of these are costs that are already factored in or not even necessary in a simple single-family house. I think it's almost heading towards 400k.

How is the property? Flat or on a slope?

Why should it be a prefab house?

400k Euro would not be affordable for us. Sounds generally quite hopeless.

The plot is flat. By the way, it is supposed to be a prefabricated house because we believed/are believing that it is cheaper and overall easier to deal with.

Thanks for all the answers.

That would be a classic house with a gable roof ("1 1/2 stories"). Only the entrance area with the staircase would be separated from the two apartments, which is more or less easily doable depending on the floor plan of the template. 80 m2 on the ground floor at level for the seniors and the attic (ideally with a small balcony) with 50 m2 for the junior. This is a slightly modified standard single-family house from the catalog! Modified insofar because of the entrance area and the second kitchen in the attic.

In addition, a small side extension for the building services, possibly with the balcony on top. The technical room, which is normally located in the main building on the ground floor, will be added to the guest WC to make it a real bathroom. Make it barrier-free right away! And the bedroom on the ground floor must be cut from the living room plus an often existing small office.

Additional question: There seem to be endless pages on this topic, how can one find (reliable) providers that offer prefabricated houses with the above-mentioned criteria, is there perhaps a list with a filter or something that only lists prefabricated houses with granny flats?

Maybe first browse the forum for half an hour, then find the right subforum “Construction Costs,” read the first 5 posts there, so you can then eat the answers with a spoon.
It’s the same with prefabricated houses. Take your time, also read something that is in front of you and answers your questions ;)

PS: Take a look at POINT 131 from Danwood regarding this. Attention, the prices do not include the foundation slab, architect, transport, and surveying; initially, calculate 50,000 EUR for these. Plus 50,000 EUR in additional building costs. Until you have reliable figures.