I remember after spending nearly a year on a 28' sailboat, as a design/builder, I started to see new opportunities in less space.

Take a boats head. They're always small, by housing standards. Our present boats head is huge compared to the one on our 28'er, but you won't see a "powder room" in a home design magazine this size. At least I haven't seen one this small.

Until now. I hate small bathrooms, especially if windowless(at least I used to). But we needed a powder room in our old house and the space under the stairs was always fair game for something. It was a game of inches(fractions), and tricky to build at times(just like a boat). 2'8" wide, it's not code, but I don't have to care about that here, I can do my own mechanical work.

The WC is full sized and location under the stairway slope was critical. Hamilton Marine supplied the tiny sink which along with one tap(hot only), is minimal to say the least. A hidden light source, exhaust fan behind the WC, that's it.