Floor plan and elevations for a single-family house of approximately 160 m² on a hillside location

Why did you fixate on a prefabricated house? I would be interested in the reason?

It was basically a decision for the building material wood in the upper and ground floors. We also have many acquaintances who built that way and were satisfied. In addition, we can separate the interior finishing and do it ourselves. This allows us to save on general contractor costs and craftsmen’s costs. (Of course, this would also be possible with a solid construction and a general contractor). But we were particularly convinced by the package with the timber construction.

Floor coverings, bathrooms, etc. will be done by ourselves)

Well, look at that, here come the next 40, 50,000… you never told me about those.

Apparently, kitchen equipment and the amount of supplies vary so much if you two already need more space.

No, we are actually very tidy. But we have dishes and an oven, and whatever one has. The most important thing, however, is storage space next to the work island and some space above the property.

I will withdraw from this. I see no potential for growth in this discussion. Here, you have to squeeze the information out of you bit by bit, that won’t work.

the kitchen is very small, too small, the island is at most 1.8m long at the end

if you subtract the refrigerator, dishwasher, oven, sink, there is only a 60 cm base cabinet left against the wall as storage space.

Oh, look, here come the next 40, 50000… you didn’t mention any of that.

No, we are actually very neat. But we have dishes and an oven, and what we have. Most important, however, is storage space next to the kitchen island and some space over the property.

I’m going to withdraw from this. I see no potential for growth in this discussion. Here, information is pulled out of you piece by piece, this won’t work.

Regarding the budget, I actually didn’t want to write anything more. But it is as I wrote above. Offers for turnkey completion are available. Garage will be added as own work. We deduct the other own work and we should be in the size range mentioned. That’s the plan. Whether it will actually turn out that way, I cannot say yet. For now, it is only an estimate. We don’t have a final offer, have to coordinate this with the architect, and there is also a lot happening currently regarding the current material and energy costs. But regarding costs and budget, I really want to leave it at that.

I am grateful for the comments on the kitchen and we will critically review this again. But currently we believe the space is sufficient. For this, we also have the kitchen of our acquaintances as a template. (maybe we are simply more Spartan than others there. For example, we don’t have a coffee machine). But as I said, thanks for the hints. We will think about it again.

: Thanks for your feedback so far. It has helped us a lot.

Of course, you can move into a house and have the same kitchen size as in a 2-room apartment. But it is neither nice nor, above all, practical. Because when two people cook together, you do need a bit more space and it is simply more comfortable. You also don’t just build a 12m2 bedroom and a 10m2 children's room just because it is sufficient. It’s also about comfort.

Turnkey is not a final price.
Take a close look at the exact equipment, usually there is more added. The electrical system is, for example, rather basic.
Construction-site provided items and those not listed are also added.

Your outdoor facilities, your earthworks, walls, supports, disposal, etc. are missing. That will be a large five-figure amount for you.
Other ancillary construction costs are still missing and are usually rather tightly calculated by the general contractors.

I am not sure whether your current 3-story plan is the most cost-effective solution.