Flat roof of 170 sqm with a basement on the slope

I think our project is very comparable. Therefore, I would say it could work, but it won’t be easy. However, I would only start once I have quotes for every trade. Because otherwise, in the current market situation, you can’t estimate costs.
What does ancillary building costs mean to you? That is probably the deciding little bit.

Off the top of my head, the following are included in ancillary building costs for us:

- Carport
- Basic terrain modeling (but not as many interventions are planned as for example was the case with you, and the current situation already eases this somewhat)
- All permits, reports, structural engineering, construction electricity, water, site setup, etc.

I don’t have the exact list in my head right now. There are definitely many more and they basically cover all outstanding points except kitchen, furniture, and lamps.

Although we feel (and actually are) not much further ahead yet, it is at least becoming clear that we are getting along with our new architects. Before we actually explain our ideas to the architect in detail, of course we want to try to define them more precisely. In the meantime, we have also tried to give more thought to what the cubature could look like. Do you think the following cubature is significantly more useful than the first one? The idea was that at least on the upper floor, the left part would only have greenery. Then also regarding the carport. Are 5 meters sufficient for two cars side by side or rather impractical? If not, the space could also be allocated to the south side.

You would have 5 m between the house wall and the property boundary? If that is the case, you won't fit 2 cars side by side there. A classic double garage is 6 m wide. I would use that as a guideline. If you plan a small room for bicycles or trash bins behind the carport, I would also allow an extra 0.5 m to comfortably get past the cars.

Thank you for the response. Yes, I almost expected that it would be a bit tight. We will have to see whether we add the 1 m to the whole or remove a bit to design it for one car and thus have more space on the left.