Single-family house with 156 m² floor area (2 children's rooms + home office)

Because of the wastewater issue? You mean because of the noises?

Yes, it's annoying when you hear the toilet flush next to the breakfast table every time.

I’m not quite sure yet how to solve that with the north orientation...

I would just rotate the house first. Does the development plan say anything about the ridge orientation?

However, we have in mind to extend the knee wall up to 1.80 m.

That is nonsense, and in three ways: Firstly, such a high knee wall does not help with "full story avoidance," because with appropriate maximum heights for ridge and wall / eaves, you might as well just put up a straight-wall upper floor. Secondly, raising the knee wall also raises the bend between wall and roof slope—with the consequence that you either have to duck to look out of facade windows or stretch to look out of roof windows; or the third option is to build dormers. Thirdly, a house styled in a "North German" manner (with clinker brick, a third gable, etc.) does not "work" if you give it significantly more than 1 m of knee wall.

I think I would rotate like kaho and then swap the office with the utility room downstairs and also move the kitchen to the other side, you will probably need the space in the utility room more than in the office. Upstairs, swap the bathroom and the bedroom so that the pipes are aligned. Swap the dressing room with the storage room and add the current storage room to the bedroom by removing the door, instead create a mini-hallway for the storage room at the back.

I also find the 180 cm knee wall height more than impractical. Neither fish nor fowl.

Before planning a house, one should know the development guidelines for a specific plot of land.

Forget this plan including the changes and take one that fits.

Forget this plan including the changes and take one that fits.

Seems strikingly true. But it could be difficult if you have fallen in love with Brad Pitt to suddenly switch to Leonardo DiCaprio. ;)