Single-family house with a small footprint, attic and basement, neighbor's approval

What exactly do you mean by 4 meters of space at the border? To the front (north), we absolutely have to keep a distance of 5 meters.

Then I will probably mean 4 meters at the side boundary, since you have problems with the 3 meters... I did mention the neighbor's garage in the next sentence :D

Oh, I have thought about that too - I could also create such an offshoot.