Tiny homes are hot right now. Tiny houses, though, are still unusual enough that I was surprised when my own sister told me she had plans to acquire one. Ruth is not the likeliest candidate for tiny living. For one thing, she collects art as an investment. So I listened with interest as she described her design for the tiny space, and clamped my mouth shut tightly as she talked about what I consider the most important part of the tiny home—the bathroom.