My floor plan for a 4-family house, please share your opinions

That's true, there is nothing worse than an apartment without direct garden access with a toddler.

Better to do without electric shutters.

I agree with my predecessors that the concept is market-economy nonsense. I find both Thies' and Yvonne's proposals much better.

Furthermore, I find it "weak" if the architect cannot fulfill the client's wish for a "bathroom with a window." I would understand that in an old building, but in a new building, it is weak.

I would say this architect is not the right one for you. Are there others?

Thank you for the numerous feedbacks!!

I would like to have the following changes made:

-Kitchens on both floors moved to the window side
-Left-opening apartment entrance door
-Uniform staircase direction, use the north side variant
-Living/dining rooms on both floors approximately 5-7 m2 smaller, instead bedrooms 2-3 m2 larger and a 3-4 m2 storage room next to the bathrooms
-Windows on the east side changed (bedroom windows oriented north-south instead of east, KZ windows 0.6 m smaller), thus providing more privacy for the rear gardens of the Maiso.-apartments
-In the attic a larger bathroom with bathtub and window, heating/storage room smaller

Start planning from scratch.

Families want direct garden access – therefore, the amenities can be simpler.
Singles or couples do not want children above them, no garden, but everything a bit more stylish and hip. High earners also pay for open living spaces and a rooftop terrace as suggested by YPG. Your family apartment is not family-friendly.

Furthermore, I find it "weak" if the architect cannot fulfill the client’s wish for a "bathroom with a window." In an old building, I would understand that; in a new building, it’s weak.

That has nothing to do with "weak." Some things just aren’t possible. Look at the client’s wishes (4 residential units) and look at the plot. And our drawing skills might be interesting, but without economic aspects: residential construction for rental is planned differently than your own house. More economically.

But as a landlord, you want tenants who find a home there and feel comfortable. (Every tenant change is uneconomical and wears down the property.) I don’t see that in the design at all. A bathroom window is a minor issue. Even without it, a floor plan can work.

Put kitchens on the window side on both floors

That’s overrated. I have my kitchen by the window (of course, it is a classic house). Still, I often have to turn the light on. The work surface that is not by the window will always have to rely on artificial light. You would rather have the light at the dining table, where office work, homework, and reading the newspaper take place.

What you’re doing now is just fussing around again without really thinking about the cause of the deficiency.

I roughly sketched my idea from this morning, assuming the dimensions of one half to be 14m x 8m. (In the picture: EG - OG - DG, WHG1 in gray, WHG2 in brown, only one half shown)

Whether it works to have the heating room partially under the stairs in a two-family house, I can't say. I left out the bay windows and projections from your plan (you don't want to increase the construction costs infinitely anyway). Maybe this requires an "extension" for the heating system or another good solution (but not in WHG2 in the DG).
There are no windows in the plan yet either, but at least the main and shower bathrooms can have some.
I would also give up the idea that the upper apartment is assigned part of the garden. I had that myself once, acquaintances have it in their rental apartment ... it’s not used.
Better to have a communal area in the east garden, a seating and grill corner that every resident or all together can use sometimes.