
Plumbing, as a practice, has existed for many centuries. Around four thousand years ago, the Minoan Palace on Crete had multiple drainage systems that emptied into stone sewers. Today, there are many options for commercial lavatories, and most of them are more complex than the Minoan plumbing system.
Interestingly, commercial lavatories can sometimes be included in political discussions. For example, when lavatories are not unisex but separated by gender, it brings in a lot of questions of who should be allowed to use which bathroom. Trans people, for example, are often discriminated against and told not to use the bathroom that represents their gender, but not their birth certificate. This often makes it difficult for people to access the same commercial lavatories and public facilities as others without risking danger to themselves.
One commercial lavatory also made a splash this spring in the headlines by having a see through mirror in a Glasglow club that allowed onlookers a look into the womens restroom, without the women there being aware. Many human rights and feminist groups have decried this since people have a reasonable expectation of privacy in bathrooms and often check up on themselves under the assumption that it is a safe space to do so.
Modern toilets in the US have remained fairly standard over the years. In Japan, however, it is popular to have complex and technological toilets that can play music, heat up, change angles, et cetera. Shower bases in Japan, while less complicated, reflect the concept of space preservation and are often very small compared to US counterparts.