Boundary construction on a non-rectangular plot (NRW)

And where is the construction window located now?

Basically, I am inclined to believe a professional. The architect is on site, knows the development plan and possibly special features. However, I do not know of any reason that would prohibit construction on the boundary - at whatever angle. Even less do I know why this should have anything to do with the neighbor's approval.

Why don’t you build exactly the 3 or 5 meters distance, but instead end up skewed? You have so much space and potential?! I would orient myself on the property boundary between 68 and 69 and plan a bit more freely towards the street. A boundary limits but does not obligate you to build on it. And what kind of drawn curve is that anyway? It looks more like a traffic roundabout.

To me, it seems that the lady made a mistake with the few centimeters or the house was planned quite tightly already, so everything was maximized in width, and now the garage, which was probably planned as secondary to the house, is extending somewhat towards the neighborhood.

And where on plot 69 would the garage be located?

On the right side from the street

from the street side on the right side

The garage is supposed to stand about half a meter from the boundary at the front? That seems very unusual to me.

Basically, I am inclined to believe a professional. The architect is on site, knows the development plan and possibly special features. However, I am not aware of any reason that would not allow construction on the boundary - at whatever angle. Even less so why this should have anything to do with the neighbor's consent.

She says the setback areas must not exceed the neighboring property by even 1 cm. See the red area. Can that be correct?