Floor plan design for a single-family house with 165 sqm including a basement and light well

Apart from square meters and the basement.

By omitting the basement, a single garage, and having a smaller, well-planned house. Otherwise, of course, through own work. You can do a lot, but you also have to do a lot for it. Can you spend 20-30 hours a week on the construction site (in terms of time and skills)? P.S. The price I mentioned includes a normal house. You already have so many special requests that I would intuitively add a bit more (bay window, tiled stove, many and large windows). That is neither efficient nor cheap.

Visible roof truss is also dog tax. Plus a fully basemented garage. I see that in the planned form and with the extras rather at 800,000 euros.

Thanks already for your reactions.

Basically, the time and the professional experience are available for most trades.

Also in the forum, there is a house with 240sqm with a double garage without a cellar where a sporty price range has been defined. Here the builder writes that he will reach/adhere to the 550k€.

It would be important for us again if there are maybe ideas and comments on the plan.

3 Notes:
Fully basemented garage including entrance stairs in it - at least this point will completely blow your budget.
I’m not quite sure where the light well is supposed to go, but you need an extremely large space for it if you want it to be visually appealing = for looking out. With a 3m boundary distance to the neighbor, it will be a bunker opening if you still want to go around the house. Source: own light well.
Then you will either not be able to use the stairs to the basement from the garage in summer, or you will have to run an electric dehumidifier continuously. You constantly bring moisture into the basement, which will cause all organic material to mold away. If the basement is to be used as living space/office, complete no-go.

btw: is this even possible with a garage and stairs directly into the basement due to exhaust gases and/or carbon monoxide?

Have you already bought the property?
With a pipe dream, though, it doesn't matter.

There is also a house in the forum with 240 sqm with a double garage without a basement where a sporty price range has been defined. Here the builder writes that he will reach/maintain the 550k€.

Then please ask directly what was done yourself.

I myself have carried out a core renovation in (almost) complete self-performance. I’m still under 800€/sqm for almost KfW 40 standard and good equipment. But it took over two years and felt like thousands of working hours (and not just felt – sometimes two hours before the office and then another 5 hours after the office or around the clock on weekends). As I said, you can build the house with a basement cheaply with a lot of self-performance, but then please also do the masonry, roofing, electrical work, technical building equipment yourself, etc. You might then be ready to move in by 2026 or 2027.
If you hire craftsmen, the budget won’t fit. Not even with preparatory work that you do yourself.

Don’t take the one or two examples that build so cheaply. Better look at how the average builds with average self-performance.