2 bungalows on 3000 sqm - multi-generation project

You are right @jpg, with a normal house there is a staircase in between

In the end, we did not like that every room is always oriented towards the terrace.

Simple solution: instead of only window fronts, also plan a wall sometimes.

The thing with the residential wings works well for older children or only 2 people

How about a covered atrium with dining in the middle, from there the wings for parents, children, living could be accessed, possibly then moving away from the square

That is also an option. Slightly reduce the atrium, eliminate the hallway areas, and then put a glass roof over the middle. But wouldn’t a living room in the middle (possibly sunken by 2 steps?) make more sense than the dining area?

Simple solution: instead of just window fronts, also plan a wall sometimes.

Although the nice thing about the Bien-Zenker U is actually working with lots of glass facing the garden. Especially since the side view won’t be so nice (slope on one side and the neighbors on the other). If you open the U towards the back, the terrace is then facing north. The garage also somehow has to be placed in front.

No, the living room is retreat, peace at the dining table is life, communication
Eating, crafting, homework, games

Whereas with the Bien-Zenker U, the nice thing is actually working with lots of glass facing the garden. Especially because the view to the side won’t be so nice (slope on one side and the neighbors on the other).

The U from Bien-Zenker should only serve as an example for you - nothing more and nothing less. An alternative to your fixed idea of the atrium.
Good house planning means using windows and walls deliberately and not simply adopting everything that may not fit on your own plot. Then the opening to the garden, the transition between house, terrace, garden.
Who wants to sit in the shade of an atrium when outside there is beautiful garden weather where you can enjoy the garden with family, tend fruit trees, weed beds and enjoy shrubs and flowering plants. An atrium may serve to bring light into rooms in an oversized house, also to create nice sight lines, but in my opinion it is not practical for living in our latitudes. Sight lines and light can also be nicely achieved in a light U or an L shape.
Basically, one should consider how/where the entrance area can be reconciled with the location of the terrace and the living spaces. For example, I don’t see the BZ-U at all on the plot here...
Regarding the atrium again: in my opinion, such a room will sooner or later no longer be used, becomes an additional burden to maintain, and will eventually be cursed and fall into disrepair. The same applies to roof terraces that only serve as an extension of the garden: one tends to stay more in the garden.

Slope is not ugly
Sure, no distant view, but it can be a view of greenery and flowers