Improvement suggestions single-family house 137 sqm GF with granny flat

Gladly

Thank you.

On the one hand, the maximum building volume is being asked for

Of course, there are many parameters that influence this. Based on the design, which with 10.50m*13.10m already fully utilizes the floor area ratio, a knee wall of about 1.80m would be possible.

whether Katja’s proposal with the children's rooms in the attic would fail because that would then be a third floor.

Yes. You are absolutely right.

Hi,
I only saw the thread today and also did some drawing.
The office would then have moved to the attic, I have a knee wall of 115 and a roof pitch of 50 and 55 degrees respectively, so you are just shy of the 9m.
Although I'm not sure about the full stories in Brandenburg whether that is possible.

The floor plan seems to me as if the mother-in-law would build and also build a granny flat for children and grandchildren who visit 2-3 times a year for two weeks. Therefore, one more vote for rejecting & restarting.