[mperham]

"Flophouses" or SROs used to provide affordable housing for young people new to a city, single people, workers, etc but they depend on density and transit to be cheap. They were largely made illegal in the mid-20th century. Land use/zoning laws are why we've built nothing but car-dependent suburbs for the last 50 years.

[lgregg]

They are still around but less common. Some progressive cities like Austin calls them a "Boarding House"[0] I'm not sure if there is a unit cap where something like your historical tenement housing could happen like in Manhattan. It's the same idea just a different format.

[0] https://www.austintexas.gov/department/get-boarding-house-li...

[bryanlarsen]

SRO's are for single people, but they're a form of shared housing, so I think the point stands.