Floor plan tube house L-shape triangular plot including oak tree

And why don't you post the view from the other side? There must already be a floor plan for that, right? Surely everyone who has taken the trouble to help here over more than 40 pages is interested in that...

To me, the entrance and the garage look like simply attached building blocks

This is due to the fact that we have to make the best possible use of the setback areas.

The main entrance can only be reached by stairs, my parents and my parents-in-law have that, I find it impractical.

Yes, barrier-free would be preferable to us as well. Maybe I'll have another design drawn up where the garage is omitted. Then the entrance area could be built in the east...

I also don't like the window in the basement

Yes, I don't like that window either. Maybe it would look better if the window sill was built half a meter higher. And it doesn't necessarily have to be around the corner.

By the way, no granny flat is planned in the basement...

Has nothing to do with accessibility. It is simply impractical to carry every crate of water, every package of noodles, every piece of furniture over it, especially as it appears that the height was created by the garage entrance.

To be exact, that one would be the most interesting

Unfortunately only in 2D...

Floor plans ground floor and upper floor...

Of course, not optimal yet.

Please refrain from comments like "too small and measly." The area is sufficient for us.

Does the floor plan fit like this or do you still need a special permit?

The large L is impractical.