Sell the property completely or partial sale with investment?

Or are there any ideas on what you can sensibly do with something like that in an apartment?

Hang at 3m and possibly put in spots. 240cm is no longer a standard; 280 cm is at least required for high-quality apartments (and those who have this height even in "normal" apartments enjoy the sense of space). Otherwise, the height is ideal for micro-apartments or student apartments. There are great concepts to design the apartment as "two-story."

The problem is that we actually aim to offer apartments between 60-70m². Even 50m² are conceivable for seniors. With that, 3.80m ceiling height feels like a train station. So it would probably come down to 1m suspension, which is really a shame.

Micro-apartments or student apartments could look like this, but is the height sufficient?

What is the distance from the window sill to the ceiling?

I think that is too tight for it.

The consultant said that ground-floor apartments are difficult to rent or not rentable at all.

The upper location is the furthest from the light, and a raised ground floor is already noticeably more attractive for break-ins than a ground floor.

Could one possibly build barrier-free here and reserve the ground-floor level for people with disabilities? Or is that also not desired there?

Accessibility is more than just being threshold-free, and a wheelchair does not cause an allergy to a penthouse view.

that we actually aim to offer apartments between 60-70m².

What is the motive behind this preference?

What is the motive behind this preference?

Money.
The debate is about dividing the floor area (680m² gross) into 8 or 6 residential units. The former would then be smaller apartments of about 60m² and certainly more profitable. The latter would be larger. You could also mix them over 4 floors.