The standard bathtub-shower design seems like a good idea. Two for the price of one. But the compromise at the heart of its design prevents it from being a good shower. The cost of the compromise is hidden in plain sight, difficult to notice due to its ubiquity. Allow me to shed some light on the ways that the tub compromises the shower.

To begin with, you can’t simply walk into the shower. You have to climb in, over a literal barrier. Clearing this hurdle is already an uncomfortable task, considering there are no clothes to soften accidental contact. But it’s not merely a matter of stepping high and long because on the other side of the barrier one must balance onefooted on ground mutated by the tub from the ideal level into a skinny ramp with sloping edges. Sure, it’s less hostile than a mine or a beartrap, but it’s shockingly inhospitable considering its primary aim is to allow a bipedal, softskinned animal to stand barefoot while being showered in water (hence the name) and contort while applying lubricants that ooze dangerously downwards onto an already slick slope. But we’re used to it, so we don’t notice its unfriendly design.

On the other hand, a shower that needs not perform as a tub can focus on being a good shower. It can be easy to enter and to exit. The ground – freed from the obligation to be gentle on a bare backside – can be tiled or otherwise surfaced with material of high enough friction so that it is easy to balance on, whether covered in soapy water or not. And it can be wide enough to allow a person to turn their body without grazing against the shower curtain or feeling otherwise constricted.

Good design, as they say, is invisible. A good shower demands no effort or conscious attention from its user. It lets them get clean while and their mind wanders wander. To achieve this, it must make it extremely easy to do all the basic things: get in, stand, wash, rinse, and get out. It sounds obvious, and yet the standard tubshower hybrid most of us have at home fails this basic test.