Does the floor plan fit? - From bungalow to two-story single-family house

Hello everyone,
we are in the process of realizing our dream house and appreciate any input.
We are renovating a bungalow, built in 1961, with an additional storey in timber frame construction. On the ground floor, we have removed some walls, creating a large open space for the kitchen as well as the living and dining areas. Our dream is to be able to see and access the garden from all living rooms. Also, to have direct access to the terrace from the kitchen. Our architect has advised us very well in this regard. However, maybe we have overlooked something in our considerations. Sometimes you can’t see the forest for the trees :) Please forgive me if there are any uncertainties; I am of course willing to make changes or additions. This is my first post in a forum. But if not now, when then. In this spirit, thanks in advance for the criticism ;)
Development plan/restrictions
Plot size: ~1300 sqm
Slope: no
Floor area ratio: oriented to neighboring development
Building line and boundary: oriented to neighboring development
Number of parking spaces: 4
Number of floors: 2 full floors
Roof type: gable roof
Style: modern
Orientation: north/south
Maximum heights/limitations: oriented to neighboring development

Requirements of the builders
Style: modern, Roof type: gable roof
Basement: partially basemented (slightly damp, so heating is planned in a separate room) Floors: 2
Number of persons: 5, age: 2 adults, children: 5 years, 3 years, 1 year
Space requirements on the ground floor: guest room, bathroom, technical room, large living-dining area, open kitchen
Upper floor: 3 children’s rooms, master bedroom with bathroom and dressing room, office, children’s bathroom, open play area
Office: family use or home office? both
Guests per year: friends with children occasionally
Open or closed architecture: open
Conservative or modern construction: modern
Open kitchen: yes, with cooking island
Number of dining seats: 8 seats
Fireplace: yes
Music/stereo wall: no
Balcony, roof terrace: no
Garage, carport: garage
Utility garden, greenhouse: no
Additional wishes/special features/daily routine, also reasons why this or that should or should not be: -

House design
Who designed the plan:
- Architect
What do you especially like? Why?
Large, open spaces on the ground floor, free open area upstairs
What do you not like? Why?
Price estimate according to architect/planner:
Approx. 450k for renovation
Personal price limit for the house, including equipment: 550k

Preferred heating technology:
Heat pump
If you had to give up something, which details/expansions
- can you live without:
- can you not live without:

Why is the design the way it is now? E.g.
Standard design from the planner?
No
Which wishes were implemented by the architect?
Windows in the stairwell
What do you think makes it particularly good or bad?: open rooms, lots of south side with glass fronts to the garden

What is the most important/fundamental question about the floor plan summarized in 130 characters?
We look forward to honest feedback. We are still unsure about the slanted wall in the left children’s room upstairs; are there alternatives? How high should the window/sill height in the children’s rooms be?

I don't understand the plan. Three full bathrooms, two of them with bathtubs? Two living rooms but only two children's rooms on the upper floor for three children? One children's room? Downstairs? And what is that huge room upstairs from the stairs? Is that about 300 sqm? It seems extremely bloated to me with a lot of walking areas. And somehow large rooms.

I don't understand the plan.

I didn't recognize the front door right away either. ;) When remodeling, you usually do: - Existing walls black, - Walls that are to be new: red - Walls that will be demolished: yellow otherwise it remains guesswork, e.g. why there is such a strange corridor between the bathroom and the living room on the ground floor?

I didn't recognize the front door right away either. ;)

I'm still looking. :) Is that supposed to be the 70 cm access for the steam cooker? :rolleyes::D Regarding the question in the title. No.

And what is this? The more I look, the more I think: huh??? And you can easily get your 10,000 steps a day in that house. :D

And is this a guest room or the room for the chauffeur?