Floor plan of a single-family house with approximately 160 m²

The two floor plans show the current status. Only the image with the location on the property and the neighboring properties does not have the current floor plan, as it is an old version and I do not have a newer one. You basically have to imagine the current floor plan on the site plan (same positioning, same orientation). However, I will also submit a newer version.

Kniestock will be reduced to about 160cm.

Otherwise, it would be more like two full stories than one and a half stories.

Where is the front door now?

As in the floor plan rather than in the site plan, I think.

Well, I understand what you mean, but the kitchen will have a lot of foot traffic, especially when guests are visiting it always has to be very clean because that's where you lead your guests through.

You could also plan a door to the living room in the hallway.

A single line could only fit to a limited extent because the terrace sliding door opens exactly in the direction where the kitchen line could be. And the wall is already 4.26 meters long; a shorter line would have even less counter space.

Think carefully about the stairs. I find the floor plan special but not completely thought through. I would choose a completely different staircase and that would result in a different layout both upstairs and downstairs.

Wouldn't it be more advantageous if the living room and kitchen swapped places including the entire bay window? Then you would have a south-facing terrace and a short path to the kitchen from the front door. Additionally, the living room would gain more depth and would not feel so narrow. This is less of an issue in the kitchen. The pantry would have to move as well - certainly not an impossible task. I don't find the children's rooms upstairs too narrow.

Wouldn't it be more advantageous if the living room and kitchen swapped places including the entire bay window? Then you would have a south-facing terrace and a short way to the kitchen from the front door. Additionally, the living room would gain more depth and not appear so narrow. This is less disturbing in the kitchen. The pantry would have to move as well - certainly not an impossible task.

I don't find the children's rooms upstairs too narrow.

I would do the same: living room at the back, kitchen near the front door. It would annoy me if the doorbell rings and I can't see who's there for a small eternity.
The most important thing for me would then also be the southwest terrace with access from the kitchen.

Basement, floors: no basement, 1.5 floors (although the drawing still shows 2 full floors)

I cannot find any storage space in the floor plan. In my opinion, the utility room is only suitable for this purpose to a limited extent. And where do you dry your laundry in winter? Are such functional rooms not important to you?