Building better homes for better health

Epidemics and health crises have, throughout history, sparked innovations in housing.

London’s 1854 cholera epidemic, for example, helped usher in advances in safe water and sewage systems. After the 2003 SARS epidemic, Singapore and Hong Kong changed building and open space standards for public housing. And today’s COVID pandemic is once again highlighting the need to improve housing to protect and improve health outcomes.

Indeed, from Italy to Brazil, countries are recognizing that poor quality and especially overcrowded housing is helping the pandemic spread. In response, Italy recently allocated 100 million euro (US$116 million) to provide improved housing to residents of a Sicilian slum where overcrowding led to one of the largest outbreaks of COVID in the country. In Brazil, where an estimated 16.7 million Brazilians live in inadequate housing, a flurry of startups are scrambling to develop and scale sustainable, low-cost housing to improve health. 

“From a pandemic standpoint, poor housing quality… especially where there is overcrowding, like slums and informal settlements, have translated into a risk of contagion,” said the World Bank’s Sameh Wahba in a recent panel on the subject. 

Housing improvements have long been seen as a tool for improving health outcomes. In 1851, for example, Britain’s Prince Albert sponsored the Society for Improving the Conditions of the Labouring Classes to develop and exhibit a Model Cottage. The building, with indoor plumbing, specially designed hollow bricks, cement flooring, and heating, was meant to improve the health and lives of its inhabitants.

A century and a half later, in 2000, Enrique Martínez y Martínez, governor of the Mexican state of Coahuila, had a similar vision. He launched a program to replace dirt floors with cement ones in homes across his state to improve household conditions and health standards of vulnerable groups. Dirt floors are harder to keep clean and therefore pose a higher risk for diarrhea and infection especially for young children who crawl or sit on them. Around the world, more than a billion people live in homes with dirt floors.

Coahuila’s program was eventually adopted and expanded by the Mexican federal government. Known as Piso Firme, or Solid Floor in Spanish, it installed cement floors in more than 2.7 million homes. A 2007 World Bank study of the program found it "significantly improves the health of young children." Among the study's findings: "A complete substitution of dirt floors by cement floors in a house leads to a 78 percent reduction in parasitic infestations, a 49 percent reduction in diarrhea, an 81 percent reduction in anemia, and a 36 to 96 percent improvement in cognitive development."

Other countries and organizations have since launched similar programs. In Rwanda, where 75 percent of people live in homes with dirt floors, the organization EarthEnable uses a specially designed flaxseed oil sealant to seal dirt floors for less than half the cost of a concrete floor.

Perhaps the most common focus of housing improvements to impact health focuses on clean water and improved sanitation. Exemplars in Global Health researchers found that Senegal was able to reduce its childhood stunting rates, in part, by improving household access to clean water and improved sanitation. Specifically, the government created a national fund to subsidize poor people’s connections to the sanitation system. The program helped improve housing, especially in Senegal’s urban areas—extending water supply services to about one million people.

National malaria programs around the world have also focused on home design as a malaria reduction tool. The Roll Back Malaria campaign along with the UNDP and UN Habitat said in a joint statement in 2015 that “there is compelling evidence that housing improvements enhance protection of residents from vector‐borne diseases. The protective effect of preventing malaria mosquitoes from entering houses and biting people as they sleep, such as by closing eaves and installing ceilings or by screening doors and windows, has been established in many settings. Likewise, improvements such as metal roofs and sealed walls that reduce harborages with favorable micro-climates for indoor resting vectors, may also reduce … the local vector population.”

The Kenyan government is also working with partners to develop housing designs that can help prevent malaria and bring those designs to market.

Today, COVID is prompting urban planners, builders, and community leaders to take another look at opportunities to minimize “the demons of density” in informal settlements. “This pandemic has made housing problems more obvious,” said Lizan Kuster, Associate Director of Entrepreneurship and Innovation for Habitat for Humanity’s Terwilliger Center for Innovation in Shelter. “As a result, there is more willingness to pilot and scale innovations to address those problems, both within government and within the private sector.”

For example, the low-income housing sector in Brazil is experimenting with new building materials that stop disease transmission including carpets that kill germs. Other “ambitious and audacious housing technologies are currently being developed and piloted,” said Andre Nogueira, Co-founder of the Design Lab and Associate Researcher and Instructor at the Harvard T.H. Chan School of Public Health. “Already, we can see HVAC technology that was one reserved only for hospitals and is now accessible everywhere. Technology comes in response to specific challenges. COVID is seeding innovations related to air quality.”

The diverse innovations currently being developed recognize that most low-income families in LMICs build their homes incrementally. This provides an opportunity to improve health outcomes by innovating on one particular product used in housing construction. For example, explained Ela Hefler, Communications Manager at Terwilliger Center for Innovation in Shelter, India’s ReMaterials Mod Roofing has created roof panels (and financing to make them affordable) that reduce indoor temperatures by more than 18 degrees – a huge health benefit when six people are trapped in a small hut during a lockdown. Other innovations include ZilperTrenchless, which is working to make clean water more accessible.

This is to say nothing of the efforts by informal settlement residents themselves to organize improvements to water and sanitation in response to COVID. These residents recognize that, as Sara Van Belle of the Department of Public Health, Institute of Tropical Medicine, Antwerp, and her co-authors wrote in an article in the International Journal for Equity in Health that "favelas, barrios, slums and shantytowns seem to be the Achilles heel of many health systems.”