4m would be ok, but 15 steps not. Where do you see the 4m?
I traced the floor plan 1:1 to scale… then I can measure the staircase. Of course, it could also be 3.97 or 4.05. The program isn’t that precise.
In #1 it explicitly said second residential unit for later.
So! I have now completely ignored that. I don’t see an apartment for 2 people, whether frail or not. I also don’t see a retirement home for you… I already call a 50sqm granny flat too small a hole for parents… yes, that wouldn’t be _my_ idea of a peaceful old age. A granny flat here can be for longer visits, grown-up children or separated or snoring partners. Or yes, a person for care.
It is what it is: follow-up applications to the building application can here only concern interior work or windows. I wanted to give up until I realized/noted that the OP wants a conservative kitchen and not such a stylish room with an island… That, I think, works quite well with the corner terrace. On the north side then a nice spot for the kids to have lunch in summer.
I chose a closed sliding door to the kitchen, also gave the staircase a wall panel instead of glass because with lots of glass and openness, you sometimes need a bit of wall and a door (even though it looks great with the cube).
Oh yes: upstairs I left out the office, because that can go under the dining area or living room in the basement with a nice light well, while the living room plus light well probably works less well because of the necessary distance to the street.
What occurs to me in principle: a door between corridor and open plan room makes no sense if you plan the stairs open or with glass.
