A few years ago, I stopped taking daily showers. Pandemic-induced work from home, moving in with a partner who showered less than me and pure, middle-age laziness pushed me to abandon an almost three-decades-long habit: So long as I don't exercise, I now shower only around three times a week.

Communal bathing could be a third approach, but it’s rarely mentioned. That’s remarkable because, in terms of resource efficiency, it’s hard to beat. Building and operating a bathhouse for 1,000 people requires much less energy than building and operating 1,000 individual bathrooms. A public bathhouse is also more efficient concerning materials, money, and space.