Floor plan of a single-family house approx. 160m², hipped roof, with basement, hillside location

I can't believe the budget or the price estimate, for three floors?!

I am reminded of my thread. Here, 9.35m exterior dimension seems to be easily enough for the open space, while 9.90 interior dimension seems too tight for me ;-)

I have a few ideas for the upper floor. How flexible are you? Would you also be able/willing to adjust the windows on the upper floor?

Your 9.90 is also a clean rectangle, this is an angle. And no 4 sqm cooking island is planned here. So the space can be sufficient. And the budget also seems tight to me. You have to be economical with the fittings.

So I consider the budget to be somewhat optimistic. What is included in the house price? Are the ancillary construction costs on a slope properly accounted for the earthworks? Is there already a static analysis? Are the requirements already priced in? What about the outdoor facilities? Garage? Upgrades? How is the garden access planned? Definitely work with correct furniture dimensions. The dining area is actually as wide as the door and no one can get between the chair and the kitchen island.

Is there a plan with elevation details? The road is definitely about 1 meter higher than the terrain, right? What is the reference point for the elevation? What does the development plan say?

Developers usually do not handle construction sites with architects. Tell me who is listed on the plan stamp. I am looking for capable architects who have expertise with slopes.

160x2.3-2.5k (depending on where you build) for the living area plus cellar 60-80k, finishing 40x0.8-1k additionally would be my rough calculation. Additional construction costs are generally more expensive on a slope than on flat ground.

Based on my own experience of a "consultation" at Schwabenhaus I hope you haven’t signed anything yet. Especially the additional construction costs were “builder’s items” in our case, so the extra costs are entirely your responsibility and if the "architect" miscalculates, that’s your bad luck.

Regarding the floor plan, I would agree with the general opinion. At the latest when it comes to the question of the U-shaped kitchen, a clear recommendation is to draw it in and then try out some distances at home with table, chair, cupboard. A pantry in that position is feasible but you don’t gain that much, an 80cm cupboard is lost for the passage, you gain that about on one side when you enter. Bottlenecks are likely around the table, realistically the dressing room only allows one cupboard placed sideways instead of a U-shape. The TV gets full western sun in the evening.

The current height difference on the property is 5 m. I have determined a 16% slope. However, the height jump to the street is not included yet. Do you have a photo of the property where you can see the offset of the street? The best would of course be a plan with height information of the street.

Ground floor underfloor heating 252.7m then basement underfloor heating 249.7m. This is how you build on a slope. Unless you absolutely want to have a basement and pay for it.