Green design gets a lot of attention for its energy- and money-saving aspects, but determining the buildings’ impacts on health isn’t always easy to quantify. But a team of researchers from Harvard, Syracuse University, and SUNY Upstate Medical Center conducted a study to help shed light on how the built environment can change our ability to think.
The team recruited 24 participants to work for six days in an environmentally-controlled space in the lab. Over those six days, the researchers changed the air quality to mimic three scenarios: a typical office building, a green office building, and a green office building with enhanced ventilation. These air states were achieved by increasing or decreasing the amount of volatile organic compounds (VOCs) and CO2 in the air, as well as the amount of outdoor-quality air per person.
The human guinea pigs were never told what kind of air they were getting, and at the end of every day they were given a test that measures cognitive function.
On average, cognitive performance was 61 percent higher in the green-building condition and 101 percent higher in the green-building-with-enhanced-ventilation condition. The amount of VOCs, CO2, and ventilation all had independent affects on how workers thought.
"Because this study was designed to reflect indoor environments encountered by large numbers of people every day, these findings have far ranging implications for worker productivity, student learning, and safety," says the study. "Green building design that optimizes employee productivity and energy usage will require adopting energy efficient systems and informed operating practices to maximize the benefit to human health while minimizing energy consumption."