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Member Research & Reports

Member Research & Reports

Harvard Study Opens the Door to Better Sleep, Work, and Health

The key to working better, sleeping better, and feeling better could be rooted in the design, maintenance, and operation of the buildings where we spend the majority of our time, a new Harvard study has found.

The national study, conducted by researchers at Harvard T.H. Chan School of Public Health’s Center for Health and the Global Environment (CHGE) and SUNY Upstate Medical, is the first to show that working in high-performing, green-certified buildings can improve employee decision-making using objective cognitive simulations.

Researchers looked at 10 high-performing buildings in five cities across the United States, including Harvard’s double LEED Platinum Blackstone South building. The team collaborated with the Office for Sustainability (OFS) and Harvard Real Estate to use Blackstone as a “living laboratory” to study the relationship between building conditions and occupants’ productivity and well-being.

The study found that occupants in high-performing, green-certified office environments scored 26 percent higher on tests of cognitive function, had 30 percent fewer symptoms of sick building syndrome, and had 6 percent higher sleep quality scores than those in high-performing but noncertified buildings.

“Our University is the perfect test bed for innovation and research related to buildings and health. Through our partnership with the Office for Sustainability, we were able to kick off our study at the Blackstone buildings at Harvard before scaling our research to four other cities across the U.S.” said Dr. Piers MacNaughton, a postdoctoral fellow at Harvard Chan School and project manager for the study.

Twenty-four Harvard employees agreed to participate in the weeklong health assessment, which included two cognitive function tests, daily surveys, and wearing watches that tracked sleep quality. On each testing day, environmental conditions, such as thermal conditions and lighting, were also monitored in each participants’ workspace.

In addition to the overall effect from being in a better building, several specific factors were found to have impacts on participants’ cognitive function scores. The high-performing, green-certified buildings used in the study had environments more frequently within the thermal comfort zone defined by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) organization, which resulted in 5.4 percent higher cognitive function scores. Brighter, blue-enriched lighting, such as daylighting, in the green-certified buildings was also associated with better sleep quality at night, which in turn led to better cognitive performance the following day. This finding supports research showing the impacts of lighting on circadian rhythm; a bigger contrast in daytime and nighttime light exposures can help regulate the release of melatonin, the hormone responsible for inducing sleep.

“Our goal is to improve the health of all people, in all buildings, everywhere, every day. To do this we are merging building science with health science and advocating for what we call ‘buildingomics’ — a new approach that examines the totality of factors in the building-related environment that influence human health, well-being, and productivity,” said Dr. Joseph Allen, assistant professor at Harvard T.H. Chan School of Public Health and principal investigator of the Healthy Buildings program at the Harvard Center for Health and the Global Environment. “We are passionate about moving science out of public health journals and into the hands of decision-makers, so we developed ‘The 9 Foundations of a Healthy Building,’ a concise synthesis of 30 years of scientific data on the key elements that make buildings healthy.”

The research grew out of the team’s previous COGfx Study, which found cognitive function scores doubled when participants were in simulated green building environments with enhanced ventilation compared to environments representative of conventional buildings. For this study, the team built on those results by going from the lab to real building environments, concluding that even in buildings that have high ventilation rates and low chemical concentration, there are additional benefits of green certification, and factors such as lighting and thermal conditions, which may improve the work and health of occupants.

Dr. Jack Spengler, Akira Yamaguchi Professor of Environmental Health and Human Habitation, the co-principle investigator of the study, placed this study in a larger context. “When you think of the urbanization that is going on around the world, we will see a doubling of our built environment before the century is over. We better do it right — energy wise, material-wise, and to optimize the human condition in those environments.”

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