Assessment of slope and basics related to the floor plan

Debt burden that crushes you
A half-finished house
For months, in your imagination, rather years no free time, no time for the family
That is not necessary

I understand. But discussing the pros and cons of owning a home here would probably go beyond the scope.

Regarding the staircase, I meant that you would even bang your head on it while crawling. It's not about a barely or 20 cm too low headroom, but the deficiency is so evident that it's almost an art to overlook it even in 3D.

I associated a workshop with a commercially used space. If that is the location of a workbench used once every two years, of course, it looks different.

As for the delta in the budget, I think that a hundred square meters would need to be painted, not wallpapered ;-)

Just to stay local and paint the offer of building plots in a positive light by including hillside locations (because otherwise nothing is available), you have to be able to afford it.

By the way, I would not refer to this as a "ground floor," since this design only has a basement and an upper floor.

The slope is not that bad after all: 2.5m over 20m. That makes 1.25m for a 10m wide house. Not much digging is necessary.
Your planned terrain alterations are not only unaffordable but also not permitted (see development plan 0.13).
If the purchase of the property works out, go to an experienced architect. He will design a nice affordable house for you there.
Here is my suggestion:

South-west terrace (not shown, as it is not allowed outside the building envelope)
Light bands to the north (the house stands about 1.20m above the ground)
Savings possible if the upper floor is planned with sloping ceilings.

The slope is not that bad: 2.5m over 20m. That makes 1.25m for a 10m wide house. Not much digging is necessary.
Your planned terrain modifications are not only unaffordable but also prohibited (see development plan 0.13).
If the plot works out, go to an experienced architect. He will design a nice affordable house for you there.
Here is my suggestion:

Southwest terrace (not shown, as it is not allowed outside the building envelope)
Light strips to the north (the house stands about 1.20m above ground)
Savings options if the upper floor is planned with sloping roofs.

Have you even read the thread completely? The OP does not want to spend more than €340k all-in including ancillary building costs. So don’t write such nonsense.
But the suggestion with more budget, i.e. at least €150k more, is really good.

Oh wow, thank you :-) Especially for the assessment of the slope. I will take a good look at it.