Eighty Percent of the Nation’s Affordable Housing Stock Exposed to Repeated Extreme Heat Events

By Mackenzie Pish, NLIHC Research Analyst 

Research published by the Union of Concerned Scientists (UCS), “Colliding Crises: The Dangers of Extreme Heat in Affordable Housing,” found that nearly 80% of affordable homes across the United States, Puerto Rico, and the Virgin Islands, and the more than seven million low-income people who live in them, were exposed to repeated extreme heat events in 2024. 

The authors cross-referenced county-level data on heat alerts issued by the National Weather Service during the 2024 Danger Season from May 1 to October 31 with the location of four types of affordable housing: public housing (872,000 homes), project-based subsidized housing (1.5 million homes), homes subsidized through the Low-Income Housing Tax Credit (LIHTC) (2.6 million homes), and manufactured housing (1.9 million homes). Combined, these programs account for nearly eight million homes. Heat alerts are issued when extremely dangerous heat conditions occur or are expected.    

During the 2024 Danger Season, nearly 80% of affordable homes (6.2 million) were located in counties with seven or more heat alerts. This includes approximately three-quarters of project-based and manufactured homes and nearly 83% of public housing and LIHTC homes. Fewer than 4% of affordable homes experienced no heat alerts. While affordable homes in every region were impacted by extreme heat, the Northeast and Southeast regions of the U.S. accounted for nearly half of all affordable homes exposed to at least seven heat alerts. 

Nearly 46% of affordable homes were in counties that experienced at least 21 days or three weeks of heat alerts, including 35.6% of manufactured homes, 41.5% of project-based subsidized homes, and more than half of public housing and LIHTC homes. In 15 states or territories, 75% of affordable homes were exposed to at least 21 alerts. The states with the greatest number of affordable homes exposed to 21 or more heat alerts were Texas (567,886 homes), California (530,361 homes), New York (498,084 homes), New Jersey (212,842 homes), and Louisiana (156,404 homes).  

People of color faced disproportionate risks of extreme heat exposure. Fifty-two percent of households in public and project-based subsidized housing are people of color, but they accounted for two-thirds of households in these programs that experienced 21 or more heat alerts. Race data for LIHTC or manufactured housing tenants were not accessible. 

The authors conclude with a call for increased investments in heat resilience for existing and new homes to avoid deadly outcomes when low-income households cannot afford cooling costs during extreme heat. They call for expansion and reform of the U.S. Department of Health and Human Services’ Low-Income Home Energy Assistance Program and the Department of Energy’s Weatherization Assistance Program. Other key recommendations provided by the authors include improved, energy-efficient building codes; mandated cooling inspections in all publicly owned or subsidized homes and requiring remedies within 24 hours; renter protections that strengthen state and local warranties of habitability to reflect cooling needs, and prohibit utility shut-offs during extreme weather; and requiring federally subsidized properties to have power backups to combat grid issues during extreme weather events.  

Read the report here.