Narrow plot, max possibilities, single-family house with low knee wall

Can you explain the ridge direction more precisely? "Along the property" is not exactly enlightening, since the property is everywhere.

If I look at the neighboring buildings, there doesn't seem to be any restriction regarding depth. What is missing in width just comes in length. But I do find it doable.

But without exact measurements and a possibly existing building plot, this is pointless guessing.

The ridge direction is predetermined as shown in the example from Escroda below on page 1. The plan so far is the survey plan, that is correct.

long ago to the property"

To the street. Many streets have this requirement, and it also makes sense here.

On 8.5 x 12 there is the classic design with utility room and office on the ground floor, entrance here from the street. The living room adjoins the garage and faces west, kitchen and dining open to the south.
Again: where is the problem?
With a 50 degree roof utilization you are brushing against the two-story height. With a dormer on the south for two rooms or a raised bay window certainly. The building authority offers an exception. It's all great.

To the street. Many streets have this requirement, and it also makes sense here.

No, precisely not.

where is the problem?

Exactly here. The house must be gable-end to the street, so you have a long eaves side and a short gable side, which means a lot of area is limited by sloping roofs. Therefore, my suspicion is that the approval authority will allow full-story dormers.

But without exact dimensions

Take my plan from #6 and make a small deduction; so 8.5m * 12m is definitely possible, IMO also 14m depth.

existing building plot

The blue line is the building boundary; to the south or sideways there is none.

What does the development plan say about the maximum number of floors? We are building on a similar footprint (7.8x11.8m) with knee wall/dwarf wall at 0.00m. In a few rooms, we have planned large dormers (almost Bauhaus style), which especially brings the entire bathroom up to full room height. That should also be feasible for you if 0.5m knee wall and 50° roof pitch are not enough. Something livable should definitely be possible on your plot.

Exactly here. The house must stand with the gable side to the street, so you have a long eaves side and a short gable side, which means a lot of space is limited by slopes. Therefore, my assumption is that the approval authority will allow full-floor-generating dormers.

I don't see any negative aspect in that
Better that way than the other way around.