House placement on a slight sloping corner lot

then you have sketched the house with 15*10m. About 20 m2 too large

Definitely not!

I don't want to be a smart aleck now.

But you are.

Even if it annoys you. The given numbers (which are unfortunately barely legible) show the building envelope.;) The 23.5 m are probably flat dimensions.

What should annoy me about that? They aren't my numbers anyway. Since I couldn't read the numbers, I placed a house of normal size on the slope - repeated. And if the OP now has more land available for the garden, that's good. But you know what can be annoying? Complicating situations: there's absolutely no intent to be a smart aleck (with ä!)! :cool: