House and Garage - Ideas for Planning Desired

It seems the planning fits, I would only probably move the garage or carport a bit "forward," that is, start the driveway length at the property boundary instead of starting it at the building boundary. In the very tight plan section, I believe I can recognize a ridge direction or house axis specification. I consider a square floor plan possible here, but one with the house axis orthogonal to the street rather unlikely (?)

How should the indication "204.20" in the plan section be understood?

People in the heath probably have a different perspective on this than in the Swabian Alb. In the SWR broadcast area, this is an average size for a normal consumer.

The indication 204.20 corresponds to the ground floor finished floor height in meters (above sea level). Our plot has a highest point in the southwest at an elevation of 205.50m and a lowest point in the northeast at approximately 203.25-203.50m above sea level.

Yes, the arrow in the plan could indicate the roof orientation... or was it the gable???

The figure 204.20 corresponds to the ground floor finished floor height in meters (m above sea level).

I already understand what kind of height it is - but what does it mean here: should it be interpreted as a site-specific reference height for eaves and ridge height?

or was it the gable???

Not the gable, usually the ridge direction, but in some development plans also the "house axis" (cf. the requirement in the thread by MBS2201, the house should have an aspect ratio of 5:4 or something similar), but here a square floor plan is probably also permitted, at least I interpret the explicit mention of the hipped roof variant "pyramid roof" in that sense.

Should one interpret them as plot-specific reference heights for eaves and ridge height?

I assumed so. The OP said in #1 that the height difference of the plot is about 2m, so the "thick" contour lines should be the full meters, the "thin" ones the half-meter lines. The one running through the building envelope would then be 204m, and then it goes up or down by half a meter towards the edges of the building envelope. If it were 203m, a basement would no longer be an issue for me.

to move the house further south and make more use of the "southwest terrace".

I don't understand. Is north at the top of the plan? How can shifting to the south then result in more southwest terrace? Maybe first cut out the possible contours (10m*10m, 11m*11m, 8m*15m, or similar) of your dream house and then place them on your graph paper. I would like to point out that according to legal regulations, the terrace counts as part of the main structure and must lie within the building envelope, unless the development plan allows exceptions. Although some administrators are not aware of this, it should be kept in mind during planning that exceeding the building line for the terrace can be problematic. I would suggest an 11m*11m house with an integrated garage on the ground floor and a 3m carport on the northern boundary, 5m away from the street. Then you have 3m to the south and 4m to the west for the terrace.