Semi-detached house in building area 8.5m x 15m (WxD)

Is each semi-detached house appraised separately in the case of ideal land division?

In ideal land division, it is viewed separately, as each person registers their ideal (land) share as well as the joint ownership in the land register. In the case of a two-family house, it is divided according to the Condominium Act (WEG), like a condominium. That is my understanding.

Perhaps you could show an aerial view of the entire street layout, if it is so difficult to access the textual regulations of the development plan. This might help to infer how the front yard is allowed to be used. I must personally admit that I have no desire to look at the neighbor's carport or garage from my kitchen or living room window.

There is something similar on my way to work. The property is similarly wide, but longer. There are also two detached houses, but the driveway and access path are similar. The terraces are set right up to the boundary; no idea how that looks legally for them. At the driveway, there is a prefabricated double garage, and on both the right and left sides there is a parking space each and the path to the houses.

.. but that is an example without Hang - right?

.. but that is an example without slope - right?

And very large building envelope. No comparison.

So ground floor? Does that automatically mean that the first full storey is at the latest 60cm above street level, even if on average less than 1.4 meters of its depth protrudes from the terrain?

The limitation of the plinth height primarily serves to prevent design misuse regarding building height. The height reference is typically the finished floor of the ground floor, below which a plinth floor (basement or cellar) is assumed. However, the house can probably also be built partially underground. The case scenario assumed by the development plan provider – even if this is probably not excluded – likely does not consider your special idea of a transversely rotated semi-detached house, but rather a single-family house. The average protrusion height of the cellar or basement is "as always" relevant for the question of whether it itself is already a full storey (and thus counts towards the number of full storeys). Assuming a height variation of 1.8 m within the building envelope, a storey height of 2.8 m, and a plinth height / height reference point of 0.6 m, the ground floor thus protrudes at the front by 3.4 m (0.6 m plinth + 2.8 m storey height) and at the back by 1.6 m (2.8 m storey height + 0.6 m plinth but - 1.8 m terrain rise) – on average 2.5 m out of the terrain, so it is a full storey (although at least for the rear half rather a basement). The cellar here is not a full storey. If you are actually allowed to build III full storeys and your attic will not be a full storey, you can have two upper storeys (and I would have to withdraw my concerns about fulfilling the space requirements). That would then, however, including the knee wall of another 0.6 m, mean a total eaves height of 9.0 m (8.4 m above the reference height).