The idea of "central with the two garden parts" I find quite good. Keep in mind that you need a long access path to the house. That is not only a cost but also potentially wasted garden space.
Do you mean completely on one level or would a small ramp outside also be a solution?
Yes, we are aware of that and would gladly avoid it (after all, I want to use the area as a garden considering the property prices :D). From the garage, we want to be able to go completely level into the house. At the house entrance (outdoor area) or directly at the house entrance, a ramp or a few steps do not bother us because we can overcome height again there.
What is important to us is that pedestrians/cars cannot directly see into our living areas from the outside... Therefore, not everything necessarily has to be oriented to the south. A living area such as the kitchen or even kitchen + dining room in the south would be sufficient for us.
Problems that have arisen:
1) Garage in front of the house: (preferred option) Our house will be built into the slope and sits lower in the terrain = less sunlight. The ground floor and garage level should at least be on one level. Accordingly, the garden level would also be roughly on this level. In the rear area of the building plot, the garden area would have to be terraced several times to compensate for the height difference of almost 3m. (Water should not flow towards the building during rain events)
2) Garage behind the house: Long driveway and more costs and less garden area --> should be avoided, but is not a no-go as long as it cannot be solved differently with the existing level, since it is more important to us that the access from the garage is level (carrying groceries, etc. is simply tedious over every step/elevation). A positive aspect would be that the house would not have to be built so deep into the slope. On the street side, the level can be raised with a retaining wall.