NOAH is the largest source of affordable housing in the United States, and the most vulnerable. Without affordability restrictions, NOAH — both rental and for sale — is fully exposed to market pressure: as neighborhoods appreciate, owners have every incentive to reposition. In Sunbelt markets, where NOAH plays an outsized role in providing affordable homes for low-income residents, pressure is accelerating quickly.
For decades, Sunbelt cities offered a distinct advantage over their northern counterparts: many moderate-income households could find homes they could afford without public subsidy. Over the past five years, that advantage has begun to weaken. Many Sunbelt markets have lost NOAH at a faster pace than high-cost northern cities in recent years, which have long maintained a larger share of subsidized housing and have increasingly relied on it to serve low-income households.
What Does the Data Show?
To explore these dynamics in more detail, we can look at three major Sunbelt cities — Houston, Atlanta, and Phoenix — with similarly sized northern cities — Chicago, Philadelphia, and Boston. Charlotte, Richmond, and Stamford round out the analysis as mid-sized market comparisons.
The data depicts a clear story: Sunbelt markets have seen the steepest decline in affordable supply relative to renter households, particularly at the 60% AMI threshold where NOAH is most concentrated.
Phoenix dropped from 82 to 64 affordable homes per 100 renter households between 2019 and 2024 — a precipitous drop of 18 points that pushed the market from near-sufficient to significantly undersupplied. Houston fell from 86 to 72, and Atlanta from 94 to 77. Northern cities held comparatively steady: Chicago and Philadelphia remained essentially flat, and Boston only declined modestly, from 97 to 93. For low-income renters in Sunbelt markets, fewer affordable homes per household means longer searches, harder tradeoffs, and ultimately, more displacement.
Five years of NOAH loss · 2019 – 2024
Sunbelt markets are shedding NOAH faster than their northern peers
average NOAH-share decline across Sunbelt cities, more than 3× the −2% drop in northern cities
Phoenix — the steepest NOAH-share decline of any market examined
affordable homes lost across select Sunbelt markets since 2019
Across the nine markets examined, NOAH share has declined in every city since 2019, but the pace of erosion tells two different stories. Sunbelt cities lost 7.1% of NOAH share on average between 2019 and 2024, more than three times the rate of decline in northern cities, which fell just 2.0 points over the same period. Phoenix saw the steepest drop of any market examined, falling from 32.7% to 25.1%, meaning roughly one in four rental homes is now affordable to households earning at or below 60% AMI. Atlanta fell from 41.6% to 34.4% and Houston from 38.3% to 31.7%.
Northern cities, starting from a higher NOAH share, have held relatively steady. Philadelphia, Boston, and Chicago each declined by three points or less. Sunbelt cities have fallen faster and further. Charlotte, which entered the period with a NOAH share comparable to northern cities, dropped by nearly 8 points, the steepest decline of any city examined. What was once a meaningful gap in affordability between Sunbelt and northern cities is now narrowing.
What Role Does NOAH Play in Housing Affordability?
Across all nine markets, NOAH is foundational to the affordable housing landscape for low-income renters. In every market considered, the majority of rental homes affordable to households earning at or below 60% AMI are unsubsidized. But the degree to which cities rely on NOAH to house their lower-income residents varies between Sunbelt and northern cities.
In Houston, Atlanta, and Phoenix, NOAH accounts for between 20% to 24% of total rentals, a substantial share, but markedly less than Chicago (41%), Philadelphia (42%), and Boston (36%). This gap is made even more consequential when considering these markets' subsidized housing infrastructure.
Phoenix has just 5.6 deed-restricted affordable homes per 100 rental units; Houston has 8.5, and Charlotte has 9.3. Boston, Chicago, and Bridgeport, in contrast, have 17.7, 12, and 15, respectively.
With far less subsidized housing to fall back on, Sunbelt cities are more dependent on NOAH as a share of their affordable inventory. In Phoenix, 77% of all rental homes affordable at or below 60% AMI are NOAH. Houston and Charlotte sit at 72% and 77%. Even Atlanta, which has a comparatively larger deed-restricted supply, still relies on NOAH for 62% of its affordable homes.
Northern cities are also heavily dependent on NOAH, with NOAH comprising 79% of affordable homes in Philadelphia, and 63% in Boston. Those markets, however, have more subsidized housing per renter household, giving them more of a cushion when market pressures hit.
The consequences of NOAH loss are direct and measurable. As affordable supply tightens relative to the number of households who need it, renters are forced into an impossible set of tradeoffs: spend more than they can afford, move farther from jobs and services, or leave altogether.
The shortage of affordable homes is not evenly distributed, and for the households most dependent on NOAH, the gap between supply and demand has meaningfully grown since 2019. In 2019, Houston already faced a shortage of nearly 58,000 affordable homes for households earning below 60% AMI. By 2024, that figure had more than doubled to 124,000. Atlanta's shortage at the same income tier grew fourfold, from under 20,000 units to over 77,000. Phoenix was not far behind, with its deficit at 60% AMI nearly doubling from 44,000 to 87,000 units. These are not gradual shifts — they are rapid deteriorations that have unfolded over just five years. Northern cities, by contrast, held comparatively steady, with Chicago and Philadelphia seeing their shortages at 60% AMI change only modestly.
Cost-burden rates have risen across nearly every market since 2019, but the sharpest increases have been concentrated in Sunbelt cities. Atlanta saw the steepest climb, with the share of cost-burdened households rising from 49% to 54.4% — a 5.4 percentage-point increase. Houston and Phoenix followed closely, each rising roughly 4 to 5 points. Northern cities, by contrast, held relatively steady: Philadelphia and Chicago barely moved, and Boston increased only modestly. The gap between Sunbelt and northern cities is narrowing, and in Atlanta and Houston, cost-burden rates now rival or exceed those in markets long considered the country's least affordable.
How Should Cities Respond?
The loss of NOAH is not an abstract phenomenon, it is felt in the daily reality of renters competing for a shrinking reserve of homes they can actually afford. As affordable supply tightens, cost burdens rise and displacement follows. And the ripple effects of NOAH loss reach far beyond individual renters. For cities that have long built their growth on an accessible, affordable workforce, losing that housing stock carries economic and fiscal consequences that are difficult to undo.
Workforce Outmigration. As working households are priced out, they take their labor with them. High housing costs limit labor mobility and slow economic growth, and for Sunbelt cities that have built their identity on an accessible, growing workforce, that risk is acute. When workers can no longer afford to live in a city, businesses struggle to hire, and the sectors most dependent on moderate-wage labor — healthcare, hospitality, education, and logistics — face the greatest strain.
Neighborhood Destabilization. As low- and moderate-income renters are displaced, the social fabric of neighborhoods shifts. Long-term residents, community anchors, and the mixed-income qualities that make neighborhoods economically resilient are replaced by higher-income households or, in some cases, vacancy and disinvestment.
Greater Subsidy Reliance. Cities that lose NOAH face growing pressure to replace it with subsidized housing, a slower, costlier alternative. Preserving existing affordable units is consistently less expensive than producing new ones and developing new housing at rents accessible to low-income households is nearly impossible without significant subsidy.
How Sunbelt cities respond in the next few years will determine their ability to continue to attract and retain companies and workers. Cities that move early, through preservation programs, acquisition funds, zoning tools, and innovative financing, have a real opportunity to protect what made them competitive in the first place.
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