New construction project single-family house in the Bergisches Städtedreieck

The fundamental factual accuracy, however, remains indispensable. Jumping over the railing in the middle of the stairs and branching off into the storage room is not a question of exact centimeters, but of essential feasibility.

I was already looking for this photo from an upper floor earlier, where it was depicted exactly the same way (i.e., half of the stairs was covered with flooring upstairs, so a door would also be accessible there). Maybe I cannot make it clear enough in the draft how it is meant.
If I find this photo, I will include it.

If the planned floor area is too small, what would be the maximum possible dimensions of the house?

I would say 12.5 meters in length is the limit, otherwise there is too little garden left. I have to measure it more precisely on site next Monday.

Your room program:
Ground floor (seniors, barrier-free):
16sqm bedroom
16sqm living room
12sqm kitchen/dining
6sqm bathroom
6sqm hallway/wardrobe/others

Your room:
Ground floor
16sqm living room
12sqm dining
12sqm kitchen
10sqm hallway/stairs
5sqm wardrobe/vestibule/storage
4sqm guest bathroom
9sqm utility room

= 124sqm

Thank you for this thread, I will spend some time on it. Maybe one should define the rooms first and then the exterior walls...

We are also here and today not at "wish for something," but at "this is how it is" and try to make the best out of the situation by involving all parties. We cannot build the Denver Clan villa here, where space is negotiable in excess ...

Ah, this statement should be pinned

Maybe I cannot make it clear in the draft how it is meant. If I still find this photo, I will post it.

Yes, I also hold the "presumption of innocence" that it is a misunderstanding due to drawing clumsiness.

Maybe one should first arrange the rooms and only then the exterior walls...

Yes, ideally always first abstractly the rooms with location and approximate size, not immediately with the exterior wall frame around it.

The question is: what do you offer the grandparents? Your wishes get inside the house. But additional space is desired there. You read walking stick and you want to address that here as well. You argue with children living in the basement. Just follow my advice in #42.

What do we offer the grandparents - the opportunity to live under one roof with the family, who are on site when help is needed and don’t have to drive hours to be helpful. Then the possibility to step out of the house and be right in the garden immediately. On the third floor, that is already much more difficult with a walking aid. And you may believe that you can still “tear trees out” over 70 - but that is far from the case. In the worst case, it may even be that only one grandparent will move in... and then 45sqm or more is available for a single person.

Regarding timber frame... yes, that was also our first point of contact. Because personally, I would have no objection to a wooden house.
We visited the prefabricated house exhibition in Wuppertal several times.
But out of sheer arrogance, overpriced gimmicks, and miserable sales talent, we backed out again. Only one company stood out, although we did not approach nearly all of them.

I admit that there is a minimum standard, which, if taken into account, also achieves more comfort. That is also our wish to address. But it can also be done, as I have personally seen, sometimes in just 4sqm in an office.