Floor plan assistance: 216 sqm single-family house with granny flat & double garage

"Our house has more rooms than we need - let's just destroy half a floor through air space." says no one ever. :D A 60 sqm eat-in kitchen with 4.x m ceiling height, a sofa floor, and then a sleeping attic with sloping ceilings? That is really messed up.

Galleries are great, but you also need the floor area for that - which you lack.
If you have your 140-160 m2 on the ground floor, it's certainly a dream.
But this enclosed air space also costs a pretty penny.

Yes, why not simply turn the most usable living space into airspace? :D

I would rather consider whether it would be possible to plan a roof terrace over part of the garage instead of living space.

A 60 sqm eat-in kitchen with a ceiling height of 4,x m,

??? I'm coming to about 37 sqm.

I would rather look into whether a roof terrace could be planned over part of the garage instead of living space.

Not a bad idea. That could be tried as well. However, it changes little about the layout of cooking/eating downstairs – living upstairs. Also, no one sits on the roof terrace if they have a proper one. No, sorry, not a good idea after all. I'm rather thinking about how to reduce the gallery a bit to realize another bedroom for the parents without losing much visually.

Galleries are great, but you also need the floor space for that - which you lack.

I don't understand that. The living area in this house is over 200 sqm.

"Our house has more rooms than we need - let's just destroy half a floor through air space." says no-one ever. :D A 60 sqm eat-in kitchen with 4,x m ceiling height, a sofa floor and then a sleeping roof with sloping ceilings? That's really messed up.

Then just ask if he's still around ;) If you already have such unusual conditions as here, you shouldn't try to make an ordinary 0815 house out of it. The space is there, as I understood it, the square meters have to be purchased. I find 's suggestions good.