The War on Roommates: Why Is Sharing a House Illegal?
Boarding houses were made illegal by zoning that enforced single family homes and by rules limiting occupancy, demanding every room have a private bathroom, outlawing shared kitchens, requiring parking spaces for every resident etc.
How States and Cities Decimated Americans’ Lowest-Cost Housing Option is an excellent, hard-hitting piece making and extending these points and significantly it’s not from a libertarian think tank but Pew:
Low-cost micro-units, often called single-room occupancies, or SROs, were once a reliable form of housing for the United States’ poorest residents of, and newcomers to, New York, Chicago, San Francisco, and many other major U.S. cities. Well into the 20th century, SROs were the least expensive option on the housing market, providing a small room with a shared bathroom and sometimes a shared kitchen for a price that is unimaginable today—as little as $100 to $300 a month (in 2025 dollars).
In the late 19th and early 20th centuries, landlords converted thousands of houses, hotels, apartment buildings, and commercial buildings into SROs, and by 1950, SRO units made up about 10% of all rental units in some major cities. But beginning in the mid-1950s, as some politicians and vocal members of the public turned against SROs and the people who lived in them, major cities across the country revised zoning and building codes to force or encourage landlords to eliminate SRO units and to prohibit the development of new ones. Over the next several decades, governments and developers gradually demolished thousands of SROs or converted them to other uses, including boutique hotels for tourists. And as SROs disappeared, homelessness—which had been rare from at least the end of the Great Depression to the late 1970s—exploded nationwide.
The Pew piece does an excellent job of documenting how laws are beginning to change. I especially appreciated this point: the simplest reform is to stop making it illegal for unrelated people to share a home!
Perhaps the simplest method of creating low-cost shared housing is to allow unrelated individuals to share a house in the same way that relatives are allowed to share a house.67 But many communities limit the number of unrelated people who can live together—in some places, to as few as two. Such laws make sharing a house for a group of roommates—which usually enables rents lower than having an individual apartment—illegal. The U.S. has a record number of unused bedrooms, but many cannot be rented because of restrictions on house sharing by unrelated roommates, even if that would be the most profitable use for the landlord and the most affordable option for the tenants.68 To enable this low-cost housing option, Iowa, Oregon, and Colorado all passed bipartisan legislation to strike down local codes that prohibit house-sharing (in 2017, 2021, and 2024, respectively).69
So many of our problems are created by busybodies and do-gooders who prevent people from using their own property.