Floor plan design for a single-family house with a conversion option to a multi-generational house

Development Plan/Restrictions
Size of the property approx. 800 sqm, 15x46m
Slope slight incline towards garden
Site occupancy index
Floor space index
Building window, building line and boundary
Edge development yes; garage, semi-detached house
Number of parking spaces min. 2
Number of floors 2
Roof shape specification gable roof
Style modern
Orientation garden west, entrance east
Maximum heights/limits
further requirements

Client Requirements
Style, roof shape, building type
Basement yes floors 2
Number of persons, 2 adults 32 & 36 + 1 child 1 year
Space requirement on ground floor, upper floor approx. 100 sqm each (living on one level should be possible)
Office: home office?
Overnight guests rarely per year
Open or closed architecture
Conservative or modern construction
Open kitchen, cooking island
Number of dining seats up to max. 8
Fireplace yes
Music/stereo wall
Balcony
Double garage
Utility garden, greenhouse yes

House Design
Who is the plan from:
- Do-it-Yourself
What is especially liked? Why? Open living-dining area, possibility to separate floors
What is not liked? Why?
Price estimate according to architect/planner:
Personal price limit for the house, incl. equipment:
Preferred heating technology: geothermal, deep drilling

If you had to do without, which details/extensions
- can you do without:
- cannot do without: double garage

Why is the design as it is now?

Development plan specifies 2 full floors, semi-detached house, roof shape and slope

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

How could one build more compactly under the condition:

Floors must be separable (multi-generational house)
Utility room on the ground floor with access to the garden must remain
Natural light in all rooms on the ground floor

The image of the property is not oriented to the north, right? Access according to the floor plan images from the east? The south side is then the shared wall with the other semi-detached house? Is that correct?

The picture of the property is not oriented to north, right? Access according to the floor plan images from the east? The south side is then the shared wall with the other semi-detached house? Is that correct?

Yes, everything is correctly stated.

Unfortunately, the room layout is not right on any floor for me.

Levels must be separable (multi-generational house)

The concept of aging retreating to the ground floor is already a declining trend. Relax your requirements by refraining from this contortion.

Well, whether this is a declining trend or not - we just want to implement it this way for various reasons.

@ myrna_loy - I can't really make much of your statement. Whether the division suits you personally or not was not my question anyway.

I would like suggestions on how to maybe make it a bit more space-saving.