Why affordable housing is more vulnerable to disasters
Despite contributing the least to greenhouse gas emissions, low-income households often bear the brunt of climate change impacts. It usually becomes evident after significant flood events, such as Hurricane Helene, which pummeled the Southern US in September 2024, or the devastating floods that inundated Nepal in July 2024. The effects of climate change reinforce the disparities already evident in the housing sector.
The economics of land use: Affordable housing's disadvantage
Land is a finite resource, and location and risk determine its value.. Affordable housing typically emerges in two primary ways: through natural market forces or government intervention. In both cases, it faces significant constraints, particularly regarding land availability.
When market forces drive affordable housing, developers or households typically seek cheaper land to reduce costs. These lower-cost plots are often in less desirable, higher-risk areas prone to flooding, earthquakes, or other environmental hazards.
This became evident, for example, in Vermont after the devastating 2023 floods, where much of the affordable housing --which was more likely to be built in low-lying valleys - was destroyed.
On the other hand, when governments initiate affordable housing projects, they, too, are often limited by fiscal constraints and land availability. Although policies may aim to reserve safer plots for affordable housing, governments frequently face the same challenges as private developers -the scarcity of prime, disaster-resilient land.
Unless it is earmarked by policy, the cheapest and most vulnerable land remains the default option for affordable housing, perpetuating the cycle of risk. The number of affordable homes at risk of flooding in the US is expected to triple by 2050.
The cost of risk mitigation and insurance
Building affordable housing on risky land presents both safety and financial challenges:
- Developers must invest in costly mitigation measures-elevated foundations, drainage systems, or reinforced structures-to meet building codes and ensure resident safety. These costs are either passed on to residents, or they are avoided entirely, compromising the housing's quality and resilience.
- Higher disaster risk inflates insurance premiums, adding a financial burden for low-income households. As climate change accelerates the frequency and severity of disasters, these rising insurance costs may render even the cheapest housing unaffordable for those who need it most.
The climate change factor
Climate change intensifies the risks facing affordable housing. As extreme weather events-hurricanes, floods, heatwaves-become more frequent, areas once deemed safe are now at higher risk. Coastal cities worldwide are grappling with more severe flooding; and low-lying areas, where affordable housing is often situated, are especially vulnerable.
This phenomenon is global in scale:
- In the Global South, affordable housing is acutely vulnerable to disaster risks, exacerbated by climate change and socio-economic inequalities.
- Over 1.8 billion people are exposed to flooding, of whom over 800 million live on under 5 dollars a day.
- In the Philippines, over 112,000 houses were partially damaged by disasters in 2023, reflecting the country's ongoing exposure to frequent cyclones and earthquakes due to its geographic location.
- From the US to India, poor neighbourhoods tend to be up to 7 degrees hotter than their wealthier neighbours with access to more greenery and parks. This heat inequality can be dangerous and lead to high mortality rates during ever more frequent heatwaves.
Vulnerable households face other risks beyond climate change-induced disasters. In Haiti, after the 2010 earthquake, and in Palu , Indonesia, after the 2018 earthquake and tsunami, the risky areas, like liquefaction zones, were largely in poorer neighbourhoods, which faced devastating losses.
Reconstruction in these circumstances is expensive, and vulnerable households are often displaced..
Without intervention, we risk promoting climate change gentrification, where the value of safer land above flood levels will continue to increase and price vulnerable households out.
A need for urgent mitigation efforts
While low-income households are disproportionately affected by disasters, the reality is that climate change poses a risk to all housing. Rising sea levels, more intense storms, and increasing temperatures will continue to impact communities of all income levels. However, the real estate prices have yet to fully reflect the growing climate risks. The current real estate market, driven by short-term profit margins and traditional valuation models, has not adjusted to these newer threats.
Government policies are crucial for mitigating disaster risks in affordable housing, often through earmarking safer land for development and enforcing safe building practices. Among vulnerable communities, awareness raising is critical to ensure that self-built homes meet minimum safety standards.
Some governments are already making changes to upgrade their affordable housing stock:
- In New Orleans, Hurricane Katrina starkly illustrated these vulnerabilities. Low-cost housing in the Lower Ninth Ward and similar areas, with low land costs but high flood risks, suffered devastating losses. In the aftermath, innovative projects like the Lafitte Greenway Redevelopment and the Mirabeau Water Garden integrated stormwater management into affordable housing developments, offering models for creating resilience in vulnerable communities.
- Superstorm Sandy exposed weaknesses in New York City's affordable housing, particularly in coastal areas like the Rockaways. Recovery efforts, though slow, led to resilience initiatives such as the Red Hook Houses Resilience Upgrades, which included floodproofing measures and elevated infrastructure. These projects serve as models for embedding resilience into public housing.
- Indonesia, a country highly vulnerable to disasters, has started to modify its expansive affordable housing programs to consider climate change and disaster resilience. By leveraging data, technology and smart subsidies, Indonesia is set to become one of the first countries to support households in upgrading their existing and new housing stock in the face of growing climate challenges.
These efforts now need to be scaled worldwide. Without them, affordable housing will continue to be disproportionately affected by disasters, with devastating consequences for low-income residents. Tackling this issue is both a matter of social justice and a critical component of building more resilient communities in an increasingly uncertain climate.
Olivia Nielsen is a Principal at Miyamoto International, where she focuses on resilient housing solutions. From post-disaster Haiti to Papua New Guinea, she has developed and worked on critical housing programs in over 45 countries. Olivia has over a decade of experience in housing finance, housing public-private partnerships, post-disaster reconstruction and green construction. Through her work, she hopes to make safe and affordable housing available to all.
Monica Sanders founded The Undivide Project, an organization dedicated to creating climate resilience in underserved communities through internet infrastructure and digital solutions. Her innovative work addresses the intersection of the digital divide and climate injustice. Monica has received major recognition throughout her career, including winning an Emmy for her coverage of the 9/11 tragedy at CNN, being named the inaugural Social Innovator in Residence at Grinnell College, and earning the Tropaia Outstanding Teaching Award at Georgetown University for her contributions to disaster law and environmental justice.
In addition to founding The Undivide Project, Monica has held prominent roles such as Senior Legal Advisor at the American Red Cross and Senior Committee Counsel for the U.S. Congress. She is also a FEMA Vanguard Fellow and serves on the National Academies of Science, Engineering, and Medicine Committee on Attribution of Extreme Weather and Climate Events and their Impacts.