Floor plan evaluation - saving square meters single-family house

Development plan/restrictions
Plot size: 751 sqm - approx. 27x27m
Slope: about 1.2m over the entire width according to the map
Site occupancy index: 0.35
Floor area ratio: 0.70
Building window, building line and boundary: present - but considered in the plan
Edge development
Number of parking spaces: no regulation
Number of floors: basement, ground floor, upper floor
Roof shape: as desired
Style: as desired
Orientation: as desired
Maximum heights/limits:
Further requirements: basically you can do whatever you want... bungalow, Tuscany style, gable roof, hip roof... can stand side by side. Orientation doesn’t matter, etc. I can also send the development plan by private message if desired.

Requirements of the builders
Style, roof shape, building type: gable roof 22*
Basement, floors: 2 full floors
Number of people, age: currently 2... 35+38— third person currently in progress
Space requirements on ground floor, upper floor: We said 140-150 sqm living space
Office: family use or home office? both
Guests per year: 0-2?!
Open or closed architecture: open
Conservative or modern construction: modern
Open kitchen, kitchen island: kitchen island
Number of dining seats: 4
Fireplace: option
Music/stereo wall: no
Balcony, roof terrace: no
Garage, carport: double garage with workshop as no basement
Utility garden, greenhouse: maybe later
Further wishes/special features/daily routine, also reasons why this or that should not be

House design
Who did the planning: planner of a construction company
What do you particularly like? Why? shape, exterior, technical room
What do you not like? Why? probably too big/expensive at 168 sqm
Price estimate according to architect/planner: none so far
Personal price limit for the house, including equipment: 450k (without garage, outdoor areas)
Preferred heating technology: air-water heat pump... but possibly mandatory district heating... nothing exact known yet

If you have to do without, which details/extensions
-can you do without:
-can you not do without:

Why did the design turn out as it is now? e.g.
Standard design from planner? no
Were corresponding/which wishes implemented by the architect? yes
What makes it particularly good or bad in your opinion?

We had expressed that it should have 140-150 sqm living space (we thought including technical room) but now it is 168 sqm.
We would really like a kitchen island, which is why the kitchen planner noted that you need at least 4m for the row opposite the island. Here it is 4.08m, so that’s okay. We only suspect the house will be over budget (we haven’t received an estimate yet). It is to be built in Northeast Bavaria near the Czech border.
Personally, we would especially see a possible saving on the upper floor in the bedroom and bathroom... but then where to reduce on the ground floor? According to the house builder, the staircase is the most space-saving version. We are not fixed on the stair shape...
The technical room should accommodate a central ventilation unit, air-water heat pump, inverter, and possibly a storage unit at some point. Also, 2m wall space for various cabinets...

Where do you think it would be possible to save something without, for example, having only a 50cm passage at the kitchen and everything being "crammed".
The garage + outdoor areas are to be done in 1-2 years. Currently, it is only about the house itself.

Thank you for your opinions

You could remove 0.3-0.5 sqm each from the top and left of the plan. Then you save a total of about 12 or 20 sqm. You can also do it on just one side. And still, the floor plan would only need minimal changes and the rooms would basically remain as currently planned.

What do you not like? Why? presumably too big/expensive at 168sqm

Against too expensive, at the top of my list for deletion would be the pillar-free design of the corner window. As a source of inspiration, I recommend to you for similarity (though with a different orientation of the house axis to the slope) the thread by

The construction cost could also be reduced by removing the corner window on the ground floor, as it has no additional benefit compared to a regular one.

You have a lot of circulation space in the middle of the rooms due to the almost square building shape and little circulation space where it would be useful. Since you have a third person in construction ( :) ), usable space in the hallway is always good? The technical room, on the other hand, can be a bit packed until it fits. Get rid of the pantry if you want to save square meters, make the dressing room smaller or also get rid of it, double access to the technical room can go. If the house were more elongated, you could save space more easily. With squares, that is more difficult.

The kitchen is actually a space-consuming status symbol in this form. And with the tight line spacing and corners of the U, not even practical.