Design for a single-family house with 160-180 sqm - suggestions for improvement?

Development plan/restrictions
Plot size: 650sqm
Slope: 2m
Site occupancy index: 0.25
Floor space index: 0.3
Number of parking spaces: 2
Number of floors: 2
Roof shape: FD

Requirements of the builders
Number of people: 2 mid-30s
Office: home office
Overnight guests per year: none so far
Open architecture
Modern construction style
Open kitchen with sliding door
Number of dining seats: 6
Garage: two parking spaces in the basement

House design
Who created the plan:
- Do-it-Yourself; adapted to the terrain by designer
What do you particularly like? Basically everything needed is accommodated; slope location makes it a bit more complex; driveway into garage is almost level, and so is the terrace; view to the south is nice
What don’t you like? Why? Bathroom on the upper floor is too small; walk-in shower and bathtub desired; widen the building by one meter overall?
Personal price limit for the house, including equipment: 550,000
Preferred heating technology: underfloor heating

Hello everyone,
We have a nice plot unfortunately with a slight slope and would like to build ourselves a new home. In the design all rooms are basically included but we would appreciate other perspectives. The bathroom on the upper floor currently seems too small to us and the layout unfortunate.

For now, you should properly set the photos. Then the site plan is missing... What are those 2 stairs on the ground floor?

Once a staircase to the basement and once to the upper floor. A continuous staircase somehow doesn't fit into the floor plan. What is wrong with the photos?

Are they standing on their head?

In my eyes, nothing fits together at all. The stairs are not aligned. No measurements at all. Structural analysis and drainage must be taken into account.

Are they upside down?

Is there any way to rotate them? I photographed them the right way up