Naturally Occurring Affordable Housing Is Disappearing

Triple-deckers, two-flats, brownstones—small multifamily dwellings go by many names and constitute some of the more unique, character-rich, affordable apartments across U.S. cities. But new research reported by The City shows that New York City has lost more than 100,000 homes since 1950 due to conversions of multifamily dwellings into single-family mansions. Drawing from work done by preservationist Adam Brodheim while studying at Columbia University’s Graduate School of Architecture, Planning, and Preservation, the article says that these conversions "have been most aggressive in Manhattan, where each conversion accounted for the loss of between six or seven units on average."

Many small multifamily buildings are considered naturally occurring affordable housing (NOAH), meaning they’re unsubsidized but rented at relatively low rates. According to a 2021 McKinsey report, these homes account for the country’s largest supply of affordable housing units.

Nationally, low-cost rentals have disappeared at a rate of more than half a million units per year between 2014 and 2018, according to a report from the Harvard Joint Center for Housing Studies (JCHS), and, without costly subsidies, developers haven’t been able to keep up with the need for replacement units due to supply constraints that have made it difficult to build housing that replaces the lost low-cost stock. These homes most frequently house low-income families and people of color.

According to a report from the Minnesota organization NOAH Impact Fund, many small multifamily dwellings are, ideally, located near schools and jobs, but the existing stock of these buildings often requires costly maintenance. "The median unit in small multifamily structures was built 54 years ago, making it nine years older than the typical single-family home…these units face significantly higher quality and structural issues," says a 2023 JCHS report.

Faced with a slew of conversions and demolitions, in 2021 the Chicago city council passed two ordinances to discourage developers from eliminating NOAH in two gentrifying neighborhoods. The ordinances fined developers up to $15,000 (or $5,000 per lost unit) for tearing down or converting multifamily buildings—the type of step that Brodheim told The City wouldn’t be appropriate for New York.

"Trying to restrict that activity is not necessarily beneficial because there is a demand for it. What this illustrates is that you just have to build a lot more housing. You have to make up for the fact that people are doing this," he told The City.

Top image: Spencer Platt/Getty

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