Is a high basement the golden middle way?

Unfortunately, I have not been able to find an exact definition of the plinth yet. So from where to where is it measured?

It does not have a special shape; it simply means the height of the finished ground floor slab above a reference point. This reference point can be, for example, a manhole cover, or the crown of the roadway before the middle of the street frontage of the property, or the average height line of where the building passes through the terrain surface (before terrain modification). Which of these applies is also specified in the textual provisions.

Also remember, even if you build a raised basement with skylights for daylight, a second escape route is still required if living spaces are defined as "underground." So, an external staircase or excavation at a corresponding window.

It says "House bases shall not exceed the height of the fixed development by more than 50 cm." No further explanation. So I'm not really sure from where to where I have to measure there.

But the second escape route is only necessary if I want to designate the basement rooms as living spaces, right?

The second escape route is only necessary if I want to designate the basement rooms as living spaces, right?

Yep.
But that’s a double-edged sword.
It can be worth it to declare less living space. Property tax, insurance (house, household contents, ...), ...
Some banks don’t like that, though, because they might use a rule of thumb to check the value of the house for loan purposes. Usable area is worth less than living space. That can become a problem. In resale, 200 sqm living space also looks better than 140 sqm.
And you should keep in mind that the rules aren’t there for fun but actually save lives in an emergency.

Due to the base rule, this will probably not work alone because of the window areas. Unless the base is defined differently. But as I said, I still haven’t found anything usable. It could be measured up to the basement ceiling, or up to the ground floor floor, or it simply refers to a recessed element on the facade. You might get useful information from the city.

How about the idea that the paved access facility is the curb?