Floor plan design - Constructive criticism welcome

I find it difficult to derive a reasonable upper floor from the (for me) suitable ground floor layout. What if I were to halve the length of the roof terrace?

Then you should start over again and not get too stuck ;)

Our architect had started planning with the [OG] for us back then. He said that is more difficult in our case. Too many wishes for too few square meters. It might perhaps be the better way for you as well.

Then you should start over again

Yes, in case of doubt, one should always feel invited to make significant changes again. An evening sun terrace as a roof terrace might be just right for a penthouse; for a single-family house, I would rather enjoy the evening sun on the terrace at the living room and garden level. That saves running up stairs with little glasses and snack bowls and pays off the "main terrace" faster ;-)

Our architect started planning the upper floor first back then. He said that was more difficult in our case. Too many wishes for too few square meters.

That's what I say. At least in the sleeping area, there are typically more rooms on the same area, or with pitched roofs on less (headroom) area. Upstairs you have to juggle with room relationships; on the ground floor it is comparatively "more equal" where exactly you arrange the spaces, which are primarily responsible for the overall generous spatial experience.

I find your floor plan idea quite interesting, but I wonder if you are aware of what the small palace will cost?

Roughly calculated with a full basement, ground floor, and set-back upper floor:

Exterior dimensions are estimated based on your measurements:

Basement: 12.0m x 11.5m x 3.0m height = 414m³
Ground floor: same as basement
Upper floor: 9.0m x 11.5m x 3.0m height = 310m³

Total therefore something around 1150m³

At €370 per m³, that is estimated construction costs of €425k.
Not insignificant, and a lot of other costs will be added.
The glass front, for example, which I would actually find really interesting. ;)

So, I don't see a granny flat with sensible light wells that don't impede the rest of the living space. They probably are not allowed to be within the setback area to the neighboring property, and you also don't want them in your own terrace area. And anyway... the apartment must also be accessible from outside.

If children's room 1 is 4 m wide inside, then there will only be a very narrow door for children's room 2 – rough opening about 80 cm or so.

Good morning everyone. Thank you very much for your many correct and important comments. We are now doing it completely new, as has been suggested several times. This time we are starting on the [OG]. The criteria remain the same. Above all, I will not give up the roof terrace facing west so quickly :-).