Floor plan, 3D images city villa 160m². Please provide feedback :)

So you mean that the floor plan is fine as it is and only the furnishing should be adjusted?

Do you need the two children's rooms and the other room on the ground floor?

Where do you want to store things like drink crates, empty suitcases, and Christmas decorations?

We had thought that we would place the drink crates in the small storage room under the stairs and store things that are not used very often in the attic. We are planning on having 2 children, but we could possibly do without the room downstairs. Maybe this would also be more sensible, in order to then move the kitchen further down and install a storage room there?

I think a small storage room on the upper floor is not a bad idea, for brooms, beach bags, etc. The washing machine there is more than practical, whether you want to keep the room or not is up to you

If you want two children, I would fix the imbalance between the parents' room and the small children's room. You would have more space for sleeping than the child has for sleeping, studying, and retreating with friends

Furnish the walk-in closet properly, the wardrobes look too narrow

Very little space between the bed and the wall in the bedroom. Try it out, considering your existing bed
Bed under the window is very impractical. To ventilate and clean, you have to crawl over the bed.

Bathtub under the window as well. I have that too and don’t find it that bad. Hand shower and the tub is clean
The shower seems quite narrow

Ground floor
Be sure to draw in your existing or desired furniture. Then you can see if there is enough space. After that, bring in more west light and improve the walking paths.

The house technology room has no space for fixtures. Next to the wall by the controlled residential ventilation, the fuse box will also go, the house connections still need to find space. Washing machine and dryer are stacked. You have to collect dirty laundry in the bathroom, no basin for hand washing, laundry basket can only stand in the middle of the room. No space for a drying rack.
At least remove the door to the carport to gain some wall space

Adjust windows you have 6 different formats.

Indent the kitchen unit a bit, this way the living room doesn’t look so tube-shaped. This also creates more space for the dining table.

This is our first (and hopefully last) construction project.

I rather think otherwise, because "both 32" speaks against it. Your generation will build again much more often before "old age" than remodeling your current house to be age-appropriate.

We have already purchased the plot (540m²) [...] We are just not quite sure about the floor plan, whether it really fits.

This design shows that a square city villa with an edge length of ten and a quarter meters already works significantly worse than one with an edge length of nine and a half meters. I’m happy to tell you a cheap trick to improve the floor plan considerably: simply by breaking away from the square dogma. With northeast child’s room, bedroom and living room, the floor plan could painlessly give up depth and rather allow more width, for example (if you want to develop the next design from this at all – it’s not bad, but not award-worthy either). 540 sqm should provide sufficient basis for more; show the plot.