Floor plan for a single-family house without a basement / 4 persons

If I copy the kitchen's wide window into the bathroom, then I'd have a window in the shower!?

Exactly. In the shower area, you can frosted window film it or something. Then you'll have a shelf for shower items right there.

Roller shutters can be omitted in the bathroom and will then be deducted monetarily.

I hadn’t considered the symbolic fifty for the saved roller shutter box; you could buy yourself an ice cream with that, so it wasn’t worth the "effort" of mentioning. But without the roller shutter box, you can gain a bit more height without colliding with the slope – I suspect that’s the reason for the reduction.

The garage is marked in green, for example.

Exactly – but also made of concrete like the ceilings? – and the masonry walls otherwise mostly made of, for example, bricks?
By the way, I see a lot of shoddy workmanship spots again. The draftsman has an unusual "method" with the dimension lines, the vertical dimensioning of the windows is completely missing.

I find it all quite nice, beautiful clear rooms.
But I don’t like the open-plan living area at all. The kitchen takes away space from the living room corner: the dining table also leans into the chill-out corner, not only when viewed from the entrance. I would steal at least 60cm from the kitchen, shift everything to the right according to the plan, and thus grant the living room at least 60cm more for the sofa. Currently, about 2.40m for a sofa is quite uncomfortable.

The sofa and dining table are just drawn as examples. On the left in the living room, there is theoretically 3.75m of space for the sofa up to the 3m sliding door. My current U-shaped lounge set with a width of 2.92m fits easily in there, or am I overlooking something? The dining table should stand centered in front of the lift-slide door.

The distance between the kitchen units is currently 1.30m. I can’t save 0.6–1.0m there!? Where exactly should I save space?

Sofa and dining table are only drawn as examples.

On the left in the living room is theoretically for the sofa.

My current U-shaped living area with a width of 2.92m fits in without any problems, or am I overlooking something? The dining table should be placed in the center of the lift-and-slide door.

Do you notice something? Theoretically and as examples have little to do with reality. Your homework is to draw in YOUR furniture and the intended kitchen planning. Otherwise, you will be surprised by six chairs crammed onto 1.2 sqm. Or you will have to look over your example dining chairs while watching TV (I currently don’t see the space either) if you plan the sofa theoretically where you say.

The sofa and dining table are only drawn as examples. On the left side of the living room, there is theoretically 3.75m of space for the sofa up to the 3m sliding door. My current U-shaped living room set with a width of 2.92m fits in easily, or am I overlooking something? The dining table should be placed in the center of the lift-and-slide door.

The distance between the kitchen units is currently 1.30m. I can't possibly save 0.6-1.0m there!? Where exactly should I save space?

I also see little room for maneuver in the kitchen. 1.30m is actually perfect as a distance. I wouldn't save space there either. What I might see as a problem is if you place the table centered in front of the sliding door and also have bar stools in front of the counter as drawn, there will hardly be any room behind the chairs to push them back (especially the middle chair needs a lot of space) and to walk along. We have about 70/80 cm space between the beginning of the sliding door and the end of the kitchen counter, and we need that to walk comfortably behind the chairs. And we don't have bar stools. With those, it would be impossible. I find the 3.75m space for the sofa perfect; if yours is only 2.90m, you still have plenty of room to walk between the sofa and the table.