Single-family house floor plan 150m², plot: 420m²

No, north orientation is not bad at all. I love it, but then I would only plan the kitchen to the north and the living room to the south.

so basically moving the entrance / the garage to the other side and then the living room there?

Are you sure that the roller shutters will work on the upper floor? The roller shutter box requires about 30 cm + thickness. Then you can plan the sill. You can plan at most one window from the floor at 1.40 - 1.50 m. But that means, depending on how tall you are, you won't be able to look out without bending down. We once thought about a 2.15 m knee wall and our architect said that we can use windows with a maximum height of 1.70 m from the floor and that roller shutters won't work then. So I'm surprised that it's different for you? Or are the roller shutters planned from the outside?

With your sofa position, you are not exactly looking into the garden.

And, you usually go from the kitchen to the garden (herbs, summer, grilling, getting a drink, etc.) rather than from the living room.

If you want the kitchen and living room separated anyway, then I would plan something like this.... This is just a quick sketch...

Here's a decent picture. The external dimensions should fit... If you find it interesting, I can also write down more measurements, but it should at least work so far and I find the orientation nicer, both for the living room and the children's rooms.