Moinsens,
we are currently in the middle of the construction phase. Attached is the floor plan again for reference.
The staircase is already being installed, although the upper floor will not be developed. Therefore, the stairwell must somehow be sealed off. For this reason, we ordered an MZ door, which will be installed on the upper floor and the remaining opening will be covered by the carpenter, including insulation. We have a meeting on site on Saturday to clarify the exact execution.
My idea is that the frame is built directly onto the opening and remains when the upper floor is later expanded, instead of a stair railing. The door will of course be removed then. The advantage I see is that later, when the children have moved out, the upper floor can again be thermally separated from the ground floor. My girlfriend is not yet quite comfortable with this idea because she thinks it blocks too much light. She is of course right, but I also consider it unlikely that the door with frosted glass insert will provide enough light anyway. Well, whatever, we don't have to decide that now.
I am currently more concerned with a floor plan for the upper floor. I have drawn one and would be interested in your opinion.
The drawing is still without consideration of the wall thickness (these will be drywall walls, due to the wooden ceiling) and losses because of the sloping wall. For now, I am only concerned with the layout itself.
Best regards