Is reserved land reasonably buildable?

So: from these points of view I see a clear longitudinal axis (eaves, ridge) parallel to the street, shallow house depth, and a moderate knee wall probably effectively around 80 cm or less. And no, you don't have to kill yourself because of that.

If I see/calculate that correctly, with the given data (with some leeway, e.g. in ridge height), I come to a maximum house depth of about 8 m. Is that plausible? Assumption ridge height 6.5 m (exists in the neighborhood) and roof pitch 35 degrees, knee wall approximately 75 cm.

If I see or calculate this correctly, I come to a maximum house depth of about 8m with the given data (with some leeway e.g. in the ridge height). Is that plausible? Assumption ridge height 6.5m (exists in the neighborhood) and roof pitch 35 degrees, knee wall approx. 75cm.

Ridge height 6.25 m minus eaves height 3.75 m = difference 2.50 m # RP 35° = 1.428 m depth per m height >> x 2.50 m = 3.57 m half house depth = 7.04 m full house depth. Conversely, with 8.00 m house depth 2.80 m difference >> eaves height only 3.45 m >> with 2.85 m story height thus 0.60 m knee wall height. These are conditions one can live with.

That means the upper edge of the basement ceiling (then also +- single-family house?) would be at 552m + 1.4m = approx. 553.5m.
Did I understand that correctly? That means you would practically come out on the highest surface of the property in the south and the basement would be approximately at the level of the terrain in the north at 550.5m.

Problem: Due to the slope, not really attractive. That makes sense. I will still try to sketch it in a section view.

Why would that not be attractive? You could excavate a bit in the north and have the option to create the house entrance on the basement level there and then have the living rooms on the ground floor with a terrace facing south. Or does that not work for other reasons?

Why wouldn't that be attractive? You could excavate a bit in the north and have the possibility to create the house entrance in the basement and then have the living spaces with a terrace facing south on the ground floor. Or does that not fit for other reasons?

At least that's one way to look at it. Attractiveness is more from a cost-benefit perspective. A "exposed" basement with a nice wide window front facing north. Ideal somehow looks different.

At least that’s what a consideration looks like.
Attractiveness rather from a cost-benefit perspective.

Is it really so extraordinarily expensive that only perfection would justify the price, or which specific desired detail would be painfully imperfectly achievable here?

“Exposed” residential basement with a nice wide window front facing north. Ideal somehow looks different.

The residential basement does not have to be fully exposed to ground level and include the living room; instead, you can also place the utility room and parts of the KGB room group in the basement, bedrooms for the parents and the youngest child in the attic, and the classic living-dining-kitchen area on the "EG" (raised ground floor/garden level). It is not uncommon for a moderate hillside location to form the basis for making something special out of a slightly varied catalog house without having to desperately resort to rounded corner windows.