It is well documented that housing is closely associated with health. The location, condition, and context of where we live intersect many factors that indirectly affect health. Our housing literally encompass environmental (think: dust and exposure to the elements) and social factors (think: isolation and crime) that directly affect health. A person experiencing homelessness would find refrigerating prescription medication that requires it to be challenging, among other threats to his or her physical and mental health. Unstable and inadequate housing contributes to stress and presents barriers to establishing social support and accessing resources and opportunities that promote health.

Historically, improvements in housing significantly reduced the spread of communicable diseases like typhoid and tuberculosis in the 19th and 20th centuries; the reductions in household crowding and improved sanitation via indoor plumbing, smooth indoor surfaces that could be cleaned, food preservation techniques, and ventilation were all powerful contributors to ameliorating these epidemics.

In the 21st century, as the public health focus has largely turned from communicable diseases to chronic ones, such as asthma, cancer, lead poisoning, and mental health disorders, the housing-health association remains significant. People experiencing homelessness are much more likely to suffer from mental illnesses and substance use disorders. Homelessness is particularly detrimental for children, and the combination of motherhood and homelessness is harmful to the mental health of mothers and associated with higher rates of substance use. But, just having a home is not enough. Housing quality is also important for health. Risk factors within the home, like lead paint or presence of dust mites, impact health, especially for children.

Still, even recognizing that links exist between housing and health is not enough to improve health. While the body of literature on housing interventions and their effectiveness is somewhat limited, we reviewed recent summaries of housing interventions to assess what is known about how, and if, they work. Here’s what we found.

Across all the studies we reviewed, investigators concluded that increasing housing affordability, access, and quality is strongly associated with positive health outcomes. The most consistent, strongest health results in the literature stemmed from interventions aimed at providing housing for people experiencing homelessness (including Housing First). Housing for people lacking it was linked to increases in stability, housing retention, wellbeing, health outcomes, and health access.

Repairs and improvements to housing were successful in reducing and managing asthma symptoms for some populations. Increasing warmth and efficiency was also associated with modest health improvements.

Authors of the literature reviewed concluded that multi-faceted, integrated models of housing produce stronger and more durable health effects than intervention components implemented in isolation. For example, dust and mold control to reduce asthma symptoms necessitates a multi-pronged approach in order to show meaningful improvement in health.

These findings, though encouraging, are limited. The literature lacks evidence on return on investment, and significant work is needed to better understand the mechanisms through which housing affects health in different contexts and for different populations. Authors of the reviews examined recommend additional research on housing and health in a number of areas, including calling for more targeted research within sub-populations experiencing substandard housing, housing instability, or homelessness in a wider range of locations. Authors also called for research on a wider range of health outcomes (many of which are infrequently studied and poorly understood, e.g., psychiatric symptoms and substance use).

Much of the research that has been done to date examines short term outcomes, but it is necessary to also investigate the long-term effects of housing, including on earnings, employment, substance use, and prevalence of chronic disease.

Finally, authors called for investigation of the interactions between individual vulnerabilities and broader determinants of health. It is critical to account for historical and political contexts to help understand the roots of these issues, and how to dismantle structures of oppression.  Housing status and home conditions are influenced by legacies of racism, classism, and xenophobia. These compromise access to safe, protected, and personal spaces that can facilitate health. We see an example of this in the practice of redlining, an appraisal system adopted by the Federal Housing Administration in 1933 that systematically denied home ownership to African Americans and systematically enforced segregation. Buying a home is a primary source of wealth for many families, so the inability to accumulate this wealth, and to pass it on to children has repercussions for generations.

Blockbusting is another discriminatory mid-20th century housing practice where realtors instilled fear among white homeowners that ethnic minorities would soon enter their neighborhood. These agents bought houses from white homeowners for well below market value and then resold them to African American buyers far above market value. These and other legacies of structural oppression have lasting implications for health. We need more research to understand these health effects, as well as continued work to dismantle persisting institutions of racism.

Research suggests that housing is deeply related to health, yet there is little understanding of exactly how, and even less understanding of which housing interventions are most likely to improve health. The current body of literature is thin, and not yet the solid foundation we need to confidently develop interventions and policies. Still, it opens the door to more research, and better understanding.

Read the full review of the literature here.