Thank you Yvonne. I didn't know what to answer.
Caspar, we are planning with around 300,000, 280,000 would be great. The problem with the built-over garage is known to us, otherwise we would need 3 floors, so the additional cost is probably roughly the same, right? Due to the edge development, the part attached on both sides should only be provided with a thin insulation layer and I hope to save insulation and plastering costs as a result.
It should be Kfw55. The heating should be an air heat pump with an outdoor unit. The outdoor unit could possibly then be placed on the flat roof.