The Health Benefits of Weatherization

March 01, 2014
March/April 2014
A version of this article appears in the March/April 2014 issue of Home Energy Magazine.
Click here to read more articles about Weatherization

The weatherization of homes for low-income households can have broad and deep effects on human health. Weatherization can reduce or eliminate many environmental risks that threaten the health of low-income households.

  • Weatherization crews reduce the danger of CO poisoning from combustion appliances. They reduce fires and fire damage by replacing malfunctioning furnaces, cleaning dryer vents, and installing smoke alarms in homes.

  • By practicing lead-safe weatherization in homes built before 1978, weatherization crews protect occupants from lead dust generated by window replacements and the drilling of holes in walls and ceilings.

  • New weatherization guidelines deal directly with proper ventilation, which can greatly improve indoor environmental quality (IEQ). Incidental health and safety repairs reduce trips and falls.

In addition, DOE’s Weatherization Assistance Program (WAP) and its evaluators continue to find new ways in which weatherization can benefit human health. Most of these benefits should reduce chronic health problems, since people spend most of their time indoors, and most of their indoor time at home.

Weatherized, Unweatherized, Heat Wave

Figure 1. This record from Chicago in the summer of 1995 shows that weatherization can make houses and apartments habitable during heat waves.

Table 1. Weatherization and Food Security

Table 2. Weatherization and Noise Reduction

Table 3. Weatherization and Sleep

Table 4. Potential Savings from Reduced Hospitalizations

Recent Research

Recent research reveals the benefits that weatherization is already providing to families and points to ways that those benefits can be expanded in the future. For example, the weatherization community in the United States recognizes the need to improve the comfort of homes in cold climates while still saving energy. However, emerging research is showing that to maintain occupant health, indoor temperatures in winter may need to be higher than was previously thought. For example, the World Health Organization states that healthy indoor temperatures are 20°C (68°F) in the living room and 18°C (64.4°F) in other occupied rooms. And the International Energy Agency (IEA, 2013) states that maintaining indoor temperatures at around 24°C (75.2°F) reduces health risks to the elderly (see “Elder Star,” HE July/Aug ’13, p. 2).

A study undertaken as part of the Oak Ridge National Laboratory (ORNL) national evaluation of WAP found indoor air temperatures in the living rooms of sample houses to be approximately 21.1°C (70°F) pre- and postweatherization. This is fine for most households, but less than satisfactory for elderly households. Although increasing indoor air temperature to reduce health risks for the elderly would take back some of the energy saved by weatherization, the study found that occupants would still use less energy than they would have used preweatherization—as a result of air sealing, increased insulation, and more-efficient heating equipment.

Weatherization and the Weather

A less-recognized benefit of weatherization is the impact that it could have during summer heat waves. The extreme heat waves that hit Chicago in 1995 and Paris in 2003 resulted in thousands of deaths. Weatherization can repair malfunctioning A/C systems, install cool roofs, and retrofit houses and apartments to make them more habitable during heat waves (see Figure 1).

The major outdoor air pollutants—tropospheric ozone, particulate matter, nitrogen dioxide (NO2), sulfur dioxide, mercury, lead, and other toxic substances—can be detrimental to human health. Outdoor air pollution can exacerbate respiratory diseases, such as asthma; cardiovascular disease, lung cancer; and stroke. Recent research suggests that outdoor air pollution may also exacerbate diabetes and obesity, cause hypertension and inflammation, contribute to prenatal insult and preterm and low-birth-weight birth, negatively affect neurodevelopment, and contribute to the development of breast cancer.

Weatherization and Indoor Air Quality

Air sealing can prevent outdoor air pollutants from entering homes, thereby reducing the incidence of these health risks. For example, modest improvements to building envelope tightness and ventilation in Finland reduced particulate matter exposure among occupants by 20% (IEA 2013). Weatherization can also prevent the infiltration of less recognized but no less harmful substances, such as pesticides and herbicides, and toxic substances released from hazardous waste spills and other accidents.

As we noted above, weatherization programs seek to improve IEQ by reducing CO, NO2, lead, mold, and moisture. A national indoor environmental study conducted by Oak Ridge National Laboratory (ORNL) found that CO levels from combustion systems were reduced postweatherization. Reducing the use of unvented portable propane heaters reduces occupants’ exposure to high levels of CO. There is also growing concern within the health and building science communities regarding emissions of NO2 from unvented gas cookstoves. Range hoods can be installed and vented outdoors to provide localized ventilation in homes where this is feasible. Eight percent more respondents used the fan regularly after the house was weatherized. The Opportunity Council (a WAP subgrantee in northwest Washington), among others, installs measures to directly reduce asthma triggers in homes where there is a child with reported asthma.

Current research in this field suggests that the more dust there is in the environment, the greater the chance of exposure to these contaminants through inhalation, ingestion, or skin absorption. Dust from the outdoors may infiltrate the home through open windows, leaky doorframes, and other air leaks in the building’s infrastructure. Dust load samples collected from preweatherized homes have contained manufactured chemicals, such as DDT, and heavy metals, such as lead (Weschler, 2013). They also contain various speciations of particulate matter (PM) 2.5 and 10. These are known contributors to, and triggers for, poisoning, asthma, and other respiratory illness, cancer, cardiovascular diseases, birth defects, and premature death. Weatherization directly addresses many of these issues through dust reduction measures, such as air sealing, cleaning and replacing air filters (including HEPA filters) on air supply lines, proper whole-house and localized ventilation, and dryer venting; and by implementing lead-safe weatherization practice during window and door replacement.

Weatherization and Mental Health

Weatherization among low-income households can reduce poverty-related stressors faced by occupants. Chronic stress is a real risk factor for health problems associated with the release of stress hormones—in particular, cortisol. High doses of cortisol released as a result of chronic stress correlate with cardiovascular disease, asthma, obesity, and anxiety disorders. Chronic physical stress causes psychosocial stress, and both are hallmarks of poverty. Research presented at a recent roundtable hosted by the IEA found that it takes only a few stressors to impair mental health and that the detrimental effect of adding stressors seems to be exponential, not linear (Liddell, 2013).

Parental depression and psychosocial stress can lead to psychosocial stress in children. Family well-being promotes secure attachment between caregivers and children, reducing both the parent’s and the child’s exposure to psychosocial stress. This in turn allows parents and children to attend to their respective educational and professional needs. A recent study conducted through the MacArthur Foundation’s How Housing Matters Research Initiative found that poor housing quality contributes to emotional and behavioral problems in children, much of this through parental stress and parenting behaviors.

Weatherization can reduce these stressors and improve poor housing conditions by addressing energy affordability issues through utility bill savings, and by improving ventilation, monitoring and installing measures to reduce combustion appliance emissions, installing CO detectors, venting gas ranges, and reducing asthma triggers.

A recent presentation by the Association for Energy Affordability in New York City captures WAP’s impact on tenants of large multifamily buildings. Many weatherization agencies have developed conditions that building owners must satisfy prior to weatherization. For example, Northern Manhattan Improvement Corporation specifies that building owners must address all NYC Code C health violations. A tenant in one multifamily building described the stress of living in an unsafe and unhealthy apartment before weatherization. She said that she felt as though she were being “pressed on,” and that weatherization created a safe living space, relieving the pressing sensation. Ameliorating the physiological and psychological symptoms of oppression and poverty is an often-overlooked benefit of weatherization.

Results of a Survey of Weatherization Participants

A national occupant survey conducted by ORNL as part of the retrospective WAP evaluation also supports the position that weatherization has health benefits. Respondents were asked if anyone in their household needed medical attention during the last year because their home was too cold or too hot. Prior to weatherization, 3.2% of the respondents said yes with respect to cold exposure, and 2.4% said yes with respect to heat exposure. After weatherization, the rates were 2.1% and 1.1%, respectively. While these percentages may seem small, it must be noted that more than 820,000 individuals lived in homes weatherized by WAP in 2010. Prevented hospitalizations and emergency room visits can save households hundreds of thousands of dollars per year.

Drafts in a home indicate how well sealed the home is from outdoor particle infiltration. The national occupant survey asked about drafts and found that before weatherization, 29% of households experienced drafts most or all of the time. After weatherization that percent fell to 9%.

Clearly, many occupants reported that weatherization reduces drafts. These results are supported by findings from ORNL’s social network study Weatherization Experiences, another component of the national WAP evaluations. Members of social networks who had weatherization work completed at the suggestion of other WAP participants reported observations related to postweatherization IEQ. Of these, 53% reported that the home was less drafty, and 43% reported that it was less dusty.

WAP seeks to reduce financial stress on low-income families by making energy efficiency more affordable. This has two benefits. First, it ensures that occupants can pay for enough energy to meet their needs. Second, when less of the family income goes to pay for home energy, more of it can go to pay for other necessities. Thirty-one percent of respondents to the national occupant survey reported that it was very difficult to pay utility bills preweatherization. This figure was reduced to 19% postweatherization. The survey also found that fewer postweatherization households were having their service disconnected, running out of bulk fuel (such as fuel oil and kerosene), and paying less than the amount owed on their utility bill.

Having more funds to pay any type of bill seems to have led respondents to make less use of short-term, high-interest, predatory loans. The occupant survey showed that the use of payday loans, tax anticipation loans, and pawn shops all decreased postweatherization. Survey respondents also reported sleeping better, enjoying more days of feeling full of energy, and feeling mentally healthy.

Findings from the occupant survey show that weatherization also increases food security. The survey inquired about potential trade-offs from energy cost savings resulting from weatherization. The results are shown in Table 1.

Weatherization may also decrease stress caused by occupants’ inability to maintain comfortable temperatures for themselves and other household members. Seventy-eight percent of respondents to the national occupant survey reported that their homes were comfortable in the winter postweatherization, versus 58% preweatherization. This held true despite the fact that both groups reported similar indoor temperature settings. The results were 70% postweatherization versus 55% preweatherization in the summer.

Poor IEQ is another evidence-based risk to human health. Individuals are vulnerable to the effects of poor IEQ resulting from exposure to gas leaks, emissions from combustion appliances, mold and other allergens, asthma triggers, and infestations of pests and rodents. Poor IEQ has been linked to depression and anxiety. Health impacts of exposure to poor IEQ, such as asthma and allergies, may result in loss of productivity at home and work, through either absenteeism or presenteeism. (Presenteeism occurs when employees go to work despite a medical illness that will prevent them from doing their job properly.) Loss of productivity through absenteeism may place financial stress on the employee. Loss of productivity in the home may lead to family dysfunction. This can place chronic stress on the family by increasing its dependence on formal and informal social networks for support, and by making parents feel that they cannot meet their family’s basic needs.

Weatherization can reduce the penetration of outdoor noise pollution to the indoors by repairing or replacing windows and by increasing wall and attic insulation. Road traffic noise at normal urban levels can disrupt communication, concentration, relaxation, and sleep—all of which leads to stress. Undisturbed sleep of sufficient length is essential for daytime alertness, performance, health, and well-being. People who do not get enough sleep often adopt unhealthy coping mechanisms. They may smoke too much, drink too much, or take sleeping pills. They may also be forced to shut their windows in an attempt to reduce noise, thereby decreasing ventilation, trapping indoor air contaminants, and making the room uncomfortably warm. All of these attempts to mitigate noise levels can cause or exacerbate health problems.

We know of no study that has extensively measured decreases in the penetration of outdoor noise to the indoors postweatherization. However, ORNL’s national occupant survey included a question about noise and produced the results shown in Table 2. Respondents also answered a question about sleep (see Table 3).

Overall, the results from the national occupant survey suggest that weatherization resulted in substantial decreases in outdoor noise as heard from indoors, and further that this noise reduction level, could, in part, be reflected in better sleep.

Synthesis: How Weatherization Benefits Human Health

In the last year before the implementation of the American Recovery and Reinvestment Act of 2009 (ARRA), DOE’s WAP supported the weatherization of almost 100,000 units with a budget of approximately $250 million. These jobs improved the homes of approximately 240,000 individuals, the preponderance of whom were children, elderly, or disabled. For the sake of the argument, let’s assume that these statistics describe a typical WAP year.

Let’s assume that weatherization, in an average year, directly prevents the premature deaths from fire, CO poisoning, and hyper- and hypothermia of at least 20 individuals out of a population of 240,000. Valuing a life at $7.5M results in a potential $150 million first-year non-energy benefit of the program. But this is just the beginning of the story. Findings from the national occupant survey found that hospitalizations for asthma and hyper- or hypothermia were down postweatherization. Now add in the potential reduction of hospitalizations and emergency room visits related to chronic and acute respiratory problems, cardiovascular disease, and mental illness (see Table 4). Even if the reductions are only in the low thousands, health and other non-energy benefits increase by tens of millions of dollars. Lastly, out-of-pocket costs to tens of thousands of households for prescriptions, emergency room visits, and hospitalizations could also be reduced. These include not only costs associated with the conditions listed above, but also costs associated with diabetes, obesity, allergies, sleep deprivation, inflammation, and arthritis, to give just a few examples. It is not a stretch to argue that the present value of all non-energy health-related benefits combined attributable to weatherization could be double or even triple the total cost of the program.

Action Plan

It is essential that the health-related benefits of weatherization be better understood and quantified. Here are five ways to accomplish this.

1. Supporting Technical Research
The argument that weatherization can reduce many environmental risks to human health is supported by numerous studies, some of which are cited in this article. However, much research remains to be done. For example, we should measure the infiltration of outdoor air pollutants into homes pre- and postweatherization for different levels and types of pollutant, for different levels of air sealing and ventilation, and for different climates and types of housing. It would be particularly interesting to measure indoor air pollutants just prior to and during major emissions events, such as a forest fire in the summer in high-risk areas. Research should also be done to determine to what extent weatherization measures can mitigate noise pollution.

2. Supporting Human Health Research
In conjunction with this technical research, human health should be tracked pre- and postweatherization. This can be done with relatively simple and short surveys or with in-depth research (such as requiring home occupants to donate blood or urine samples for biomarkers and to undergo regular medical examinations). These data should be supplemented with data describing increases or decreases in medical costs. All this data can be combined with data on weatherization measures installed and job costs to identify the most cost-effective ways to achieve both energy savings and health benefits.

learn more

To read the full report on which this article is based, write to Bruce Tonn.

Get more on MacArthur Foundation’s How Housing Matters Research Initiative.

Find out more about the Association for Energy Affordability.

The references in this article are available at


Coley, R. L., et al. (2013). "Relations Between Housing Characteristics and the Wellbeing of Low-Income Children and Adolescents." Developmental Psychology 49, no. 9 (2013): 1775–89.

International Energy Agency. "Summary Workshop Report." Capturing the Multiple Benefits of Energy Efficiency: Roundtable on Health and Wellbeing Impacts, Copenhagen, April 18–19, 2013.

Liddell, C. "Tackling Fuel Poverty: Mental Health Impacts and Why These Exist." Paper presented at Capturing the Multiple Benefits of Energy Efficiency: Roundtable on Health and Wellbeing Impacts, Copenhagen, April 18–19, 2013.

Weschler, Charles. Indoor Environments: Shaped by Interplay of Human Bodies with Chemicals of Outdoor and Indoor Origin." Environment and Health – Bridging South, North, East and West (August 19–23, 2013).

3. Collaborating with the Medical Community
The weatherization community needs to work with the medical community to design and implement research projects. This requires close collaboration. As the medical community learns more about the benefits of weatherization, perhaps doctors will “prescribe” weatherization, along with medicine, to their patients—to be implemented by local weatherization programs. This innovative idea is taking hold in other locales outside the United States, such as Liverpool, England (IEA 2013).

4. Extended Leveraging
Extended leveraging takes the weatherization community beyond the usual leveraging provided by energy assistance programs and utility companies to include a whole range of human-health-related organizations. These organizations include public and private health insurance programs; public- and private-sector organizational wellness programs; public health departments; and even federal, state, and local air pollution monitoring programs.

5. Contributing to the Exposome
The exposome is the totality of environmental exposure that affects the health of an individual over his or her lifetime. To describe the exposome, health researchers will need to collect a great deal of data on the exposure of individuals to a very wide range of potentially harmful substances. The weatherization community can contribute to this endeavor by working with researchers to monitor IEQ and occupant health in real-time conditions, in samples of homes pre- and postweatherization. The local weatherization agencies are ideal collaborators, because they are trusted, well-established resource providers within their communities. This work could be a springboard to other leveraging activities involving technology that could benefit the agencies’ clients. An example would be smart-home technologies that connect clients to their doctors’ offices.

Our vision of the health benefits of weatherization is exciting but clearly aspirational. To realize this vast array of benefits, weatherized homes should receive a full complement of measures, the installation of which will require innovative leveraging arrangements with the medical community and others. More research can measure and fine-tune our understanding of the health benefits of everyday weatherization practices that WAP has been performing and will perform in the future. We look forward to the day when doctors can write a prescription for weatherization!

Bruce Tonn is a senior researcher; Erin Rose, who holds an M.S. in Social Work, is a researcher; and Beth Hawkens, who contributed to the article, is a research associate in the Environmental Sciences Division at ORNL.

This article was sponsored by DOE's Weatherization Assistance Program through the Oak Ridge National Laboratory.

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