For example, in the hobby room I would match the window to the one in the utility room and give the dining area an undivided fixed element.
Good point, thanks! Something will change there anyway, since there should also be an access from the hobby room to the garden. Regarding the dining area, I like your approach; we will plan for something a bit larger or undivided there.
My comment referred to the separation of the garage construction application
Meaning: yes, it is possible?
The garage on the boundary is certainly on average higher than 3 m. It also looks much steeper than the contour lines would suggest.
Is something like that allowed according to the development plan?
Why shouldn’t it be allowed? As far as I know, the only limiting height according to the development plan is the 8m ridge height.