A Heat Map Of New York City’s Hidden Slums

An infographic by SITU Studio maps where illegally subdivided apartments house New York City’s hidden density.

It’s no secret that New York is an expensive place to live. Luxury condos proliferate, but affordable housing does not. More than half the renters in the city are considered rent-burdened, meaning paying more than a third of their monthly wages just for housing.


That means for the city’s poorest residents, rental housing situations can get a little…creative. And not in a good way. “A lesser-known consequence of the affordability crisis is an informal rental market that has illegally adapted, subdivided, and converted existing apartment buildings, townhouses, and high-rises to accommodate the lowest-paid populations,” as a new urban design exhibition at the Museum of Modern Art, Uneven Growth, notes.

As part of the exhibition, SITU Studio, a Brooklyn-based design studio, mapped the geographic spread of these illegally subdivided, high-density dwellings across New York City–places that in other metropolitan areas, like Mumbai or Rio de Janeiro, would be considered slums. “In New York City, you have slums, but they’re not visible,” Basar Girit, a partner at SITU Studio, tells Co.Design.

“I think we wanted to bring that to people’s attention,” he says. “As opposed to, ‘It’s a luxury city,’ how are people at a low income level actually making their lives in a city like that?” The designers created a heat map of complaint calls made to the city Department of Buildings–not a comprehensive sample of the illegal dwellings in the city, but “those are the only real indicators,” as Girit explains.

The studio estimates that as many as 200,000 illegally converted dwellings exist in the city, including subdivided apartments, basements, attics, and industrial spaces. Largely concentrated in the far-flung reaches of Queens, the Bronx, and eastern Brooklyn, many of the residents of these illegal spaces are immigrants–often undocumented–and the informal nature of this particular housing market makes it difficult for tenants to claim basic housing rights that exist in other parts of the city. SITU Studio worked with local groups to gain access to some of these apartments, photographing and virtually reconstructing some of these hidden pockets of hyper-density.

Though the highest concentration of 311 calls about illegal dwellings come from more remote stretches of the outer boroughs, they also come from some of the city’s most expensive pockets–like the Upper East Side. Essentially, unless you’re living in a multi-million dollar penthouse, all of New York City is a slum.

About the author

Shaunacy Ferro is a Brooklyn-based writer covering architecture, urban design and the sciences. She's on a lifelong quest for the perfect donut.