Raise the Floor
Keep the space empty. Hide the bed. Hide the dining room.


Two hinged benches are pulled out of the floor.  The space between them should provide a comfortable dining room experience.
Revealing the bed hides the desk area.  Revealing the desk hides the bed.
Storage is available under all the stairs.  Could contain long storage bins for maximum storage.

There is no kitchen, yet.
There is no bathroom, yet
No privacy, but there is crawl space to hide in.