When the Bermondsey Public Baths opened in 1927, only one out of every 500 houses in this working-class London borough had a bathroom.
What they lacked at home, including a lavatory of their own, local residents found in all but Roman splendour in a grand municipal building boasting two swimming pools and 126 private baths in cubicles along with Turkish and Russian baths, steam rooms and saunas.
For centuries, in many parts of the world, this is how people without access to bathrooms kept clean. The Bermondsey Public Baths were closed in 1973, by which time it was increasingly hard to find an old house, and certainly not a new council flat, lacking a plumbed-in bathroom.
In medieval England, people washed in highly social public baths influenced by those of ancient Rome, Byzantium and North Africa. Shared by men and women, in 1546 these ‘bagnios’ or ‘stews’ were closed for good by Henry VIII because of the licentious behaviour they encouraged.
The English, resorting to spices, herbs and scrubbed clothes to stay fresh, were never as clean again, at least not until the building of municipal public baths in the 19th Century, by which time industrial grime had seeped deep into the skin and psyche of much of the population.
The flushing lavatory had been invented by Sir John Hennington, poet and godson of Queen Elizabeth I, and improved with an all-important S-bend to trap sewage smells and gases by the Scottish watchmaker and inventor Alexander Cummings in 1775. But it was only when homes were fitted with running water and effective drainage from the second half of the 19th Century that the modern private bathroom emerged. Before this, bathing and relieving oneself were bodily affairs conducted in any convenient room and, of course, outdoors. For many people, throughout the industrial world, baths were something taken in tin tubs in front of kitchen fires until well into the 20th Century.
For most people even on comfortable incomes, the 20th Century bathroom remained a hospital-like space with sparse white fittings and limited hot water
Because bathrooms were associated first and foremost with hygiene – it is easy to underestimate how grimy industrial towns and cities were until remarkably recently – they were fitted out, for the most part, in clinical fashion. Yes, there had been wondrous town and country houses and villas equipped with impressive bathrooms, all roll-top Victorian tubs with lion’s paws feet, elaborate Edwardian shower hoods and richly patterned tiles.
There were exotic bathrooms, too, like that of the deeply romantic Villa Kerylos (1908) at Beaulieu-sur-Mer, a 2nd-Century-style Greek villa on the French Riviera designed for Theodor Reinach, the French archaeologist, with all mod cons and a bathroom of great beauty that visitors gawp at today with a sense of wonder and longing.
However, for most people even on comfortable incomes, the 20th Century bathroom remained a hospital-like space with sparse white fittings and limited hot water. And, where in the present century ever more people expect multiple bathrooms and lavatories, there was usually only one of each even in detached, four bedroom homes built up to World War Two.
Privacy remained important. Influential modern houses like the American architect Philip Johnson’s Glass House (Canaan, Connecticut, 1949) and Mies van der Rohe’s Farnsworth House (Plano, Illinois, 1951) might have been all but transparent, yet both featured modest bathrooms secreted behind solid partitions.
Something changed in the 1960s, with rising prosperity in developed countries and a pop culture focussed increasingly on pleasure. Adorned with sunken bath, bidet, shag-pile carpet, louvred wardrobes, plastic mirror cabinets, swirly patterned waterproof wallpaper and even a Jacuzzi (the Whirlpool was patented in the United States by Candido Jacuzzi in 1964), the archetypal ‘60s bathroom was the very model of a private “bagnio”.
Since then, in affluent and fashionable homes, contemporary bathrooms have come to resemble those of opulent new or refurbished hotels, with the bathroom evolving into a sensual home spa, and an opportunity to showcase luxury or affluence to visitors.
Something changed in the 1960s, with rising prosperity in developed countries and a pop culture focussed increasingly on pleasure
Technology has kept pace, with everything from heated toilet seats and optical-illusion wash basins to remote-control flushing and shower gadgets available to anyone building a bathroom today.
With the dawn of social-media apps, many restaurants and hotels use their bathrooms to showcase their style or personality, hoping their Instagrammable facilities will spread hype and attract more customers. In London alone, the egg-pod toilets at Mayfair’s Sketch, the mirrored bathroom within Nopi restaurant, and the ’loos with a view’ within the Shard skyscraper are just a few that regularly feature in social-media brags.
Today, when some 60 per cent of the world’s population is without access to a flushing lavatory, design magazines and websites are still awash with images of ambitious and aspirational bathrooms. These are often fronted by floor-to-ceiling picture windows overlooking cinematic views of cityscapes and, if not these, then of forests, mountains and oceans.
In a curious way, this longing to wash in sight of nature takes us back to traditional public bathing, not medieval ’stews’ or municipal baths in poor areas of industrial cities, but to the smoke saunas of Finland and the sento (communal bath house) and onsen (natural hot-spring bathhouse) of Japan, where bathing and cleansing, despite advances in plumbing and bathroom equipment, remain purist and age-old rituals.
To comment on and see more stories from BBC Designed, you can follow us on Facebook, Twitter and Instagram. You can also see more stories from BBC Culture on Facebook and Twitter.
If you liked this story, sign up for the weekly bbc.com features newsletter called "If You Only Read 6 Things This Week". A handpicked selection of stories from BBC Future, Culture, Capital and Travel, delivered to your inbox every Friday.