Rough cost estimate for roof extension

I would like to convert the attic. At the moment, the whole space is quite low; I would like to remove the entire roof here and put up a new one. At the same time, I would ideally like to build as wide dormers as possible on both sides. The house has a base area of 14.70 by 7.73 meters. If any other data is needed, I can of course provide it. Some rooms should then be added up there. (The layout is flexible, just an idea at the moment). Can you recommend a height for the whole thing? Should the knee wall then be built higher, or is it done with wood? In terms of insulation, I would like full coverage. Regards, Steffen

What exactly do you want to hear now? Put a pitched roof or a flat roof on it, then you have the best use of space. Are you aware that you cannot just build in Germany? There are usually development plans - if not, the neighborhood or zoning plans apply, which can prescribe building heights and/or roof types. Have you clarified that in advance? If you are not allowed to build it, it’s a moot point anyway.

I live in the south, where it sometimes snows. A flat roof is out of the question because it always leaks. And I have the lowest house in the neighborhood, the others all have one whole additional floor on top (so about 3 meters higher). Maybe there's someone who is a carpenter and can roughly tell me how much a m² of roofing costs?