Why do many San Francisco houses have working bogs in the course of their garages?

9:40 a.m. Tue, February 20, 2024

If you're driving through San Francisco, you might pass a house with the garage door open and be surprised by a toilet in the middle of the garage. What gives?

One theory is that these are examples of the “Pittsburgh toilet,” which originated in the Pennsylvania city in the early 20th century. (Video above.) Back then, steelworkers and miners used these individual toilets and accompanying sinks to relieve themselves and wash off the day's dirt before entering the house. But that may not be the case in San Francisco.

From SFGate:

San Francisco real estate agent Ciara Piron has a different theory for these toilets, at least the ones prevalent in the Sunset District. She has seen many of these standalone toilets while selling homes in the area and took it upon herself to do some research. She found that in 1928, 26 houses were built on just one block. This is a quick construction method, and it assumes that the workers building these houses would need somewhere else to “go” while the houses were being completed – portable toilets had yet to be invented.

Instead of removing the additional toilets after construction was completed, workers left the new homeowner to decide their fate[…]

Another popular theory for the existence of these toilets in San Francisco attributes them to some sort of plumbing protection. If there is a sewage backup in the home's system, it would likely erupt in that system at a lower level, where less damage is likely to occur and cleanup is easier.