New single-family house 160-170 sqm, 3 children's rooms

I don't know the exact values, but purely visually:

Neighbor_R: Low knee wall (~1m), steep roof pitch as the attic is also converted (no idea if officially or not), visually a very high roof.

Neighbor_L: Very low knee wall (small thatched roof house) and instead a very modern flat roof extension with >80sqm.

So no city villas or similar, which might not make the argument any easier.

We had a maisonette apartment. Both floors under the sloping roof despite the relatively low knee wall. You can, for example, build the 1st floor with 160 cm and 40 or 45 degrees roof pitch, two nice rooms should fit into the attic. The point is that the appearance fits, your budget is maintained and two additional rooms can be created relatively cheaply.

The house is indeed too small but that’s how I meant it. Google "Favorit Massivhaus" Noblesse 121

Favorite solid house Noblesse 121

Why does a detached terraced house come to your mind as an example?

Detached terraced house I can't breathe from laughing. It was just an example with an attic. Admittedly not the best.

Bigger and with knee wall it looks different. With 1.5 stories and 0-4 children, you don't have much left. - Expansion reserve - Keep extension in the back of your mind - build large with 4 children's rooms that end up empty

In the show house in Fallingbostel. You can view it on the Vierbrockseite.

Can you please name it? Viebrockhaus has several more show houses in Bad Fallingbostel