Revisions log for Answer #1615

This is all wrong.

A good planner/architect designs one at a time.

The floor plan always grows with the view of the facade, which means: the professional can watch both at the same time and can mentally assess the consequences of changes inside or outside, respectively, outside and inside.

— If the homeowner likes non-traditional modernism, a narrow floor-to-ceiling window can easily be placed on the outside wall of the toilet, if the rest of the time requires it.

— If the wall moves inward, the designer knows that the window can also be moved, which can then affect other floors.

I assume the design is handmade and worth reviewing even without a window.

You can build a single pitch roof in a variety of ways, but somewhere in the middle the supporting wall should provide stability, but that's where the window is, which the designer probably wouldn't have planned there ;).