You can really do without the questionnaire!
it’s not about dutifully filling out the form, but about your individual habits, preferences, about the WHY. Somehow you can live behind every door. Maybe you can still add something..... I would definitely want a bathtub in the house, especially because of children, and I say this as someone who doesn’t bathe; upstairs there is enough space in the bathroom. You absolutely have to fill in all the measurements, furniture, bed, dining table, sofa. The bedroom upstairs could become very cramped with only 10 sqm, so I would skip the sliding door there, also because it’s almost always left open anyway.
Size of the plot: very large to huge. There is enough space
and why must it then be a two-story house, that is with a knee wall of 2 m. This can also cause problems such as a "normal window being too low/for a roof window too high." Why not have more ground floor area and thus a more spacious open-plan room and less upstairs? Or do you have a special house type like a "villa" or something similar in mind? You do have a huge, beautiful plot, you write...
Gable roof, but relatively flat
why? Does that result from your living preferences?
modern but simple and plain
....but it won’t be cheaper just for that alone. Most (including me) say “simple” but then often choose the high-quality anyway.
open or closed architecture: open to the back, there is a large wide garden
....and why then don’t you plan it really open and generous exactly there? So far, there are rather few window surfaces on this supposed prime side, and the open-plan room is rather tiny.
Balcony, roof terrace: yes, enough space around the house is available
EXACTLY where is the terrace supposed to be? Where is the prime side? Maybe a smaller terrace separately for morning or evening sun or to smoke a joint in peace in the shade?
-Architect basically sketched after my drawing
Then it’s probably not a “free” architect; such a one would most likely have refused to sketch something after your drawing, let alone do it. Is it supposed to be a general contractor? Prefab house?.....??? Are you already fixed?
What do you particularly like? Why? The straight staircase for the look, open area and orientation to the back
Such a staircase needs an adequate space to have impact. Currently, in your plan you have a narrow endless corridor, which with 11.62 sqm area represents one of the largest rooms in the house. By the time you get to the kitchen, you’re parched; coming out of the kitchen it feels more like a labyrinth. Cloakroom etc. is currently only possible under the stairs. As soon as you draw in real measurements for the furniture, you will see that it pinches everywhere. Let go of all your ideas and internal stipulations and go back to zero or start with YOUR needs! Whether it then becomes a flat x-roof, with or without a gallery or a straight staircase is totally irrelevant. Your unnecessary stipulations for such gimmicks are currently blocking you from a nice floor plan. First of all, I would move the office upstairs or enlarge the ground floor so that you can create at least some spaciousness in the open-plan area downstairs. Currently that is 34 sqm!!! The utility room will get a few sqm, the ground floor bathroom without a bathtub will give up some space, the staircase will be appropriate for the house so that you get a proper cloakroom. I have built before and practically “forgot” the cloakroom, what a mess!