Floor plan: Semi-detached house 8x12m. Opinions and creative ideas welcome :-)

Is that a semi-detached house (Doppelhaushälfte)? Did I overlook that? Can you please provide the exterior dimensions of the entire boxes?

Exactly, it is a semi-detached house. Exterior dimensions are 8x12m (plot 11.1mx37m)

What do you mean? Are they supposed to move in when they are older? Is an office needed or would a desk corner somewhere also do?

"Yes and no" in case of needing care we want to take them in, so space should be planned for that even if it is uncertain - hence also the office.

Then I would really try to design the kitchen differently and create an intermediate space between the technical room and the kitchen. It doesn’t have to be wide, maybe one meter. The shower downstairs... I can absolutely understand the reasons. But three showers in such a small house and only for a contingency... Mh. But of course, you have to decide that in the end yourselves.

Yes, that’s true. Maybe the kitchen can be a bit smaller. I will test that. Thanks! And regarding the shower - yes, we may need to talk about it again. If there is enough space otherwise... I’m just put off by the cleaning. Perhaps it could be planned so that the fixture is there but one initially forgoes a shower and adds one if necessary. That might be worth considering.

Just a question: what would you think about planning only a guest WC with a shower downstairs and just an extra WC upstairs for the kids? When the kids are older, they can put their stuff in the guest WC and then their shower will be downstairs?

Just a question: what would you think about only planning a guest WC with a shower downstairs and just an extra WC for the kids upstairs? When the kids are grown, they can put their stuff in the guest WC and then that would become their shower downstairs?

The question is what you would gain from that...? But from the idea itself: yes, I think it makes sense. We also have a second shower (or rather shower preparation) downstairs.

But I didn’t understand the thing with the stairs. The short side (the 8m side) faces southwest. We planned the stairs on the wall of the other semi-detached house half.

But it is not irrelevant which wall is now the partition wall.
The floor plan develops according to the possibilities and circumstances. Afterwards, windows are placed and room positions are developed.

But since both are cut exactly the same, it is "actually" completely irrelevant for the floor plan. Only in this case, it would be a bit darker than the other side.

No, even if something is "only" mirrored, it is a completely different house and concept if a house tends to exist more in the shade than on the south side.
I don’t understand your problem now of somehow incorporating the site plan, sketch, or so here.
This discussion will never be half and half here.

When the kids are grown, they can put their stuff in the guest bathroom and then their shower is downstairs?

I don't find that very appealing. If the shower is on the same level, you can quickly hop naked into the room. If you have to cross half the house between the room and the shower, you always have to remember to take your clothes with you, etc.
The question is also whether the room downstairs and the bathroom are large enough for (people in need of care? people with limited mobility?) to live there.