ᐅ Semi-detached house – Floor plan improvements

Hello everyone,

I wanted to get some opinions from you regarding our floor plan to potentially identify any major mistakes that we might not be considering at the moment. We are building a semi-detached house.
Exterior dimensions approximately 10.99 m x 9.99 m (36 ft 1 in x 32 ft 9 in), solid construction.
Room layout ground floor: entrance area, utility room, cloakroom, WC, straight staircase, living/dining/kitchen, pantry.
Room layout upper floor: 2 children’s bedrooms, 1 master bedroom with walk-in closet, bathroom, storage room.
Room layout attic: studio, office, free space.
Two full stories, attic roof pitch 36°.

And here is the completed questionnaire:
Plot size: > 444 m² (4,780 sq ft)
Slope: no
Number of parking spaces: 2
Number of stories: 2 full stories
Roof type: gable roof
Style: classic, simple
Orientation: east
Number of occupants, age: 2 people, 25 and 28
Room requirements ground floor, upper floor: see above
Occasional overnight guests: rare
Open or closed architecture: open
Conservative or modern building method: modern
Open kitchen, kitchen island: preferred
Number of dining seats: if possible 8
Fireplace: currently none in the plan
Music/stereo wall: yes
Balcony, roof terrace: no
Garage, carport: yes, see floor plans
Vegetable garden, greenhouse: no

House design
Who designed it: architect
Estimated cost according to architect/planner: 400,000
Preferred heating system: not yet decided

Why does the design look the way it does now?
We wanted to design the ground floor as an open space combining the living, dining, and kitchen areas. The usual utility rooms in prefabricated houses are far too small for us, so we made ours a bit larger. The straight staircase certainly takes up quite a bit of space and causes a large corridor on the upper floor with some loss of area as well. However, we like the open concept. It is also worth mentioning that we raised the ceiling height on the ground floor to 2.75 m (9 ft) to make the rooms feel more spacious. Since we are planning to have children in the next few years, 2 children’s bedrooms are planned on the upper floor. We are less happy with the bathroom because, due to the staircase, it ends up quite narrow and corridor-like.
Originally, we did not plan to develop the attic, but since we urgently need an office and there was no space left on the main floors, we placed it there. Additionally, the attic provides enough space for future expansion if a child would like to have their own area there.

I would appreciate any feedback.