Cost of semi-basement two-family house, garage with two spaces

Greetings from Kassel! We want to build a two-family house with a basement and a garage for 2 cars. We visited various companies and each told us something different. Does anyone have experience or has built a house before and can roughly estimate and advise? What is safer: turnkey construction or rather an architectural office and individual companies working together? Our house will have about 90sqm per floor plus the basement and the garage. Plus furnishings, etc. Some said we can manage with €300,000. Some say about €1400 per sqm should be calculated PLUS architectural services and additional costs. So about €400,000 without land. Now we are desperate... we look forward to feedback or maybe someone can recommend a good company?

Hello,

take a look here, it could already give you some clarification. If not, ask again.



Rhenish greetings