Floor plan 3 children's bedrooms single-family house - potentials?

We used to have an emperor, but nowadays 570 sqm is already quite decent; for a detached single-family house, about 450 sqm is considered the minimum size, which in my opinion is also sufficient. More would be more comfortable, but first you have to be able to get it.

That's just silly. You yourself say that it is only slightly above the minimum size, or how else should I interpret the objection? For buildability, it is completely irrelevant whether it was hard to get. Small remains small.
The OP wants to place his garage within the building envelope. At the moment, given the size of the plot, this is a tight matter and the reason why any floor plan discussion is initially obsolete as long as the exact dimensions of the building envelope are not known.

Attached are some measurements from the development plan. The garage is aimed to be 5-6m wide. Number behind = is in meters.

[ATTACH alt="grundriss-3-kinderzimmer-einfamilienhaus-potenziale-646862-1.jpg"]82997[/ATTACH]

Black dashed/blue would be the building window

That's silly. You yourself say that it is only just above the minimum size, or how else should I interpret the objection? For buildability, it is completely irrelevant whether it was hard to obtain. Small remains small. The OP wants to place his in the building window.

I don't call almost 27% above the minimum size "just above." I am not aware of Muslim cars, so you simply do not align the garage towards Mecca, so what. In the west there is nothing new either, but at least a Ga/Cp building window large enough for a double garage. I would much rather drive in and out of that than to circle around the tree island. From my point of view, a shortage only arises here if the OP, despite having his own garage building window, unnecessarily reduces the house building window in order to move the garage to the morning sun side into the house and garage building window.

A shortage arises here in my view only if the OP, faced with their own garage building window, unnecessarily reduces the house building window by bringing the garage on the morning sun side into the house and garage building window.

The insight is quite glorious, after we finally know the dimensions of the building window. Only the budget is still missing.

The realization is indeed very glorious, after we finally know the dimensions of the building envelope.

Glorious, no. I am a construction consultant - not a general. And I have had that realization since the first glance at the snippet of the development plan. Where a development plan assigns two differently dedicated building envelopes to a plot of land, it is ALWAYS self-flagellation to "bring the dog into bed" (and the remaining house building envelope must fundamentally also allow the development according to the plan - here E/D - despite this division, otherwise the measure would be disproportionate). I do not need "exact" dimensions for that.