New York City has lost 100,000 apartments because people in rich neighborhoods keep combining units

• New York City is facing down a housing shortage, all while some apartments disappear.
• Around 50,000 multi-family row houses have been consolidated to become one- or two-family homes.

New York City, famed for its residents stacked upon each other, is actually quietly losing density in some places — and you can blame people expanding their apartments.

An analysis from preservationist Adam Brodheim found that, over the last 70 years, 50,000 multi-family buildings in New York City have been converted into one or two family homes — adding up to a loss of 100,000 units.

"I'm not trying to begrudge folks who are trying to build a larger apartment as their families grow," Brodheim told the New York Times. "I'm trying to bring attention to the way these actions across the entire city make a meaningful impact on our housing crisis."

As Brodheim wrote in his master's thesis, first covered by The City, many row houses have served as multi-family residences at one point. Across 320,777 row houses in New York City, 51,221 have been converted from multi-family to accommodate just one or two families; out of that around 50,000, 7,219 have been turned into single family homes.

Similar research from urban planner Matthew Pietrus found that apartments were disappearing due to consolidation the most in New York's wealthiest neighborhoods, including the Upper East Side, the West Village, and Cobble Hill.

Apartment consolidation isn't necessarily a bad thing. If homeowners want or need more space, they should have the option to create it, especially given the dearth of apartments with more than two bedrooms in New York. But it's quite concerning in the context of a severe region-wide housing shortage that's forcing lower- and middle-income people out of the Big Apple and making life in the city unaffordable for millions of others.

New York's rate of new housing construction has slowed to a trickle in recent years as rents and home prices have skyrocketed, fueling a citywide affordability crisis. While the number of jobs in the city has grown by 22% since 2010, the housing supply has grown by just four percent. More than half of New York City renters are rent-burdened, meaning they spend more than 30% of their income on rent, the state found this year. Many studies have found that growing the housing supply — even if it's market-rate — slows rent and home price growth.

Manhattan — the wealthiest borough — is the epicenter of the crisis. For example, the number of new housing permits in Manhattan dropped from 1,208 in July 2013 to zero in July 2023. Citywide, it fell from 2,525 to 279 during the same time period. And while Manhattan is the slowest of the boroughs to convert multi-unit homes back into less dense dwellings according to Brodheim's analysis, it has still lost around 27,000 units through consolidation. This is all made much worse by the even more anemic pace of housing construction in many of the city's suburbs.

Some developers are aiming to ameliorate both the housing shortage and post-pandemic glut of office space in the city. As office towers see record-high vacancy rates amidst the remote-work revolution, Mayor Eric Adams' administration is pushing for more empty offices to be turned into apartment buildings. There's already one amenity-laden former workspace getting ready to rent out nearly 600 units by the end of the year.

But that'll still be just a drop in the bucket of the housing the city needs.

Adams says his "City of Yes" housing plan — a slew of zoning reforms to incentivize more and denser housing construction — would create 100,000 new homes for 250,000 New Yorkers over 15 years. Adams has set a broader "moonshot" goal of building 500,000 new homes in the city in the next decade, which is in line with the city's estimated 560,000-unit shortage. To put that in perspective, just 25,936 new homes were built in the city last year — about half of Adams' annual goal.