New single-family house 190 m² for a 4-member family

Have now adjusted the windows and doors/door hinges as well as swapped the children's room.

As a layman, I would see the need for at least one beam in the living room, which on one side cannot rest because the terrace door is there.

As already said at the beginning, the structural engineer has something to do there ...

The plate is much too narrow. How is one supposed to use it???

The corridor is far too narrow. How is anyone supposed to be able to use it???

Especially when you consider that there is supposed to be an open passage to the technology:

I'm wondering anyway whether just a passageway would be enough

Why build a wall at all then?

It was the seller's suggestion so that you don't storm directly from the kitchen into the technical room. But I think you're right, if you put a large cupboard or shelf there, it also looks separated and you have more flexibility.

Especially considering that there is supposed to be an open passage to the technical room:

Why build a wall at all?

Was the seller’s suggestion so that one does not storm directly from the kitchen into the technical room.

How did the seller justify that? – who gets traumatized at the sight of canned goods and dust bags, especially when the view also catches the heating distributor and the fuse box?