Floor plan: ~150m² single-family house bathroom arrangement on the upper floor

For several days now, I have been moving things back and forth on the upper floor, more hallway, less hallway, rectangular rooms, rooms with recesses, etc.
Somehow, nothing feels "right"; does anyone have suggestions?

Attached is the "site plan"

[*]Pink = Plot (still needs to be divided among the heirs of the large one)
[*]Purple = this is where the house should go (to the left are fruit trees and to the right there should be enough distance as the land is not necessarily staying in the family)
[*]yellow = parents' house including garage

Development plan/restrictions
Size of plot: ~4,000 m²
Slope: no
There is no development plan and the building authority was apparently unreachable/unoccupied both last week and today.
Spatially, we are "in a village;" in the street there are terraced houses, a detached villa, a classic single-family house, adjacent to the plot there is a villa type with a half-hipped roof with an opposite flat-roof bungalow.

Client requirements
Style, roof shape, building type: Classic single-family house with gable roof at about 22~25° pitch, preferably 2.15 m knee wall and approx. 1 m roof overhang. (Main focus on photovoltaic system)
Basement, floors: 1.5 or nearly 2 stories, no basement.
Number of people, age: currently 1 working adult ;)
Space needs on ground floor, upper floor: "sufficient"
Office: home office, full-time
Guest sleepers per year: max 1
Open or closed architecture: rather open
Conservative or modern construction: cost-conscious and simple to implement, therefore rather conservative
Open kitchen, kitchen island: optional, currently favoring U-shape
Number of dining seats: 6
Fireplace: no
Music/stereo wall: no
Balcony, roof terrace: rather not
Garage, carport: no
Utility garden, greenhouse: both present
Further wishes/special features/daily routine, also reasons why something should or should not be

The floor plan should be arranged so that living on the ground floor is possible after retirement.
The study will become a bedroom, the staircase will get a side wall and be extended into the bathroom with a "front door."
I am aware that without a soundproof ceiling/stairwell this is not considered a separate apartment. (I might build it myself)

House design
Who designed it:
Original from Fingerhaus Neo 200 (mirrored vertically and horizontally) or Kampa Lanos.
Due to the location of the plot (road to the south), I moved a few walls and objects using Gimp.

What do you like in particular? Why?
I am happy with the ground floor layout; also everything fits with the staircase. I was able to see something similar in the model house park.

What do you not like? Why?
Upper floor, more precisely the bathroom.

Price estimate according to architect/planner: -
Personal price limit for the house including equipment: ~400k
Preferred heating technology: air heat pump

If you had to forgo certain details/extensions
-you could forgo: walk-in shower
-you could not forgo: study on the ground floor, straight staircase, walk-in shower

Why did the design turn out the way it is now? E.g.
Ground floor
* WC not facing the (side) street and as a proper bathroom with washing machine
* Utility room only as large as necessary to maximize living/working room
* Large study is a must, view of the front garden and some street seems better to me than the shadow on the north side.
* I am still debating whether a sliding door to the terrace is needed or if a normal/double door would be better.

Upper floor
* Neither the separate master bathroom nor the 6 m² dressing room appealed to me.
* Air space (center north) makes no sense above the newly arranged kitchen
* Windows on the roof sides are currently not planned

What is the most important/basic question about the floor plan summarized in 130 characters?

How can the bathroom and adjacent rooms be sensibly arranged without moving the staircase?

Any criticism/suggestions for the rest are welcome, I probably overlooked/forgot something.

Basically not too terrible. The bathroom upstairs is obviously nonsense, but that can be fixed. The T in the guest WC is also crazy - a normal arrangement should work though. The protruding office door must be aligned again - doable. However, the measurements are questionable. It's all quite tiny, I'm afraid. The dark hallway upstairs and the "noses" on the children's rooms are also rubbish, they still have to go. But for a first idea - you can continue with that. If you are building just for yourself, then why not a bungalow?

Number of people, age: (still) 1 of working age ;)

Sorry, but one wonders whether you are 20 and working on your first child or 65 and about to kick the bucket? I hope the former.

I would move the house slightly towards N. You do have space.

You are apparently planning for a family (children's room and bedroom under the roof)?! Then you are planning the jack of all trades for later. That does not work like this. The ground floor is not independent: the office is far too small to accommodate a bedroom with a double bed and especially a wardrobe. There is no storage room. The stairs lose the cloakroom if you put a wall there. The shower WC is far too small to also serve as a laundry space. It does not work. The passages are too narrow. And in old age, one should rather have space instead of corners and narrow passages.

One does not have to say anything about a granny flat on the upper floor at first, but if so, it should also function.

For living with a family in the near future, the room layout at 9.80 is too short or the space is not well used: the living room is too small/short, the freezer room with storage space is too small. The island is too narrow, the floor gets greasy there.

Basically, I would move the house further north!

I am missing a project plan for the division of the back three quarters of the property in all this site planning – are they supposed to get a cul-de-sac access, or should they only be accessed via GFL through your driveway ... ?

For several days I have been moving things back and forth on the upper floor, more hallway, less hallway, rectangular rooms, rooms with recesses, etc. Somehow nothing feels "right", does anyone have suggestions?

Number of people, age: (still) 1 of working age

Yes, I recommend you – unfortunately you have to google externally, preferably with the quotation marks – "The upper floor has priority", and, given your sitting shower on the ground floor, also "Wrong paths of forward-looking house planning" and in addition "When is it time to think about 'building for old age'?" But before that, you should find your future wife , because otherwise you won't experience retirement in this house. Wives do not like moving into a "finished" nest already completed before they met.

Did you complain about the first post?