Onna yu (“Bathhouse Women”) by Torii Kiyonaga

Siegfried Giedion, in Mechanization Takes Command, writes:

I have described how in the western world, the disparate functions that take place in the modern bathroom used to be separate, but courtesy of the engineers and plumbers, all ended up in one room because it was cheap and convenient, not because it was healthy or right.

In Japan, this didn’t happen. They have been taking bathing seriously for over a thousand years, starting as a religious ritual and becoming a social one. Because human waste was so valuable as fertilizer until the development of the Haber-Bosch invention of artificial fertilizer, the toilet didn’t come inside until well into the 20th century. When it did, they kept it in its own room, as bathing was social and regenerative, while using the toilet is private. Also, until after WWII, the Japanese used squat toilets, which are a lot smellier. Nobody would think of mixing the two functions.

But there are other good reasons to separate the toilet in its own room; it is more sanitary. In my post for LifeEdited, Re-Thinking the Bathroom: Who Needs It? I noted that toilets put out a lot of bacteria when they are flushed, which settles everywhere, including your toothbrush. According to Dental Health Magazine,

So how might one combine the best of Japan’s bathing ideas with American housing? Perhaps like this terrible sketchup drawing I have done. You enter in the middle, in what in Japan would be called the Datsuiba, or changing room. Bruce Smith and Yoshiko Yamomoto describe it as

To the right I have drawn a room for the toilet. To the left is the bath, with the shower separate from the tub. In my post Save Water; Shower Japanese Style I described the process of showering before bathing:

No doubt readers are going to complain that this takes up too much space, being 14’ long compared to a standard American bathroom at 8’ long. But how many bathrooms do most American apartments or houses have? In this bathroom, three people can be doing different things at once. If a bathroom is eliminated, this design would actually save money and space.

Next: Part 7: Going off-pipe.The History of the Bathroom Part 1: Before the Flush

The History of the Bathroom Part 2: Awash In Water and WasteThe History of the Bathroom Part 3: Putting Plumbing Before PeopleHistory of the Bathroom Part 4: The Perils of PrefabricationThe History of the Bathroom Part 5: Alexander Kira and Designing For People, Not Plumbing