Michigan State University researchers surveyed two groups of employees, 263 in total, working in conventional office buildings and in LEED-certified buildings in the same area of East Lansing, Mich.
They found that moving to LEED-certified buildings contributed to reductions in self-reported absenteeism and stress and improved the workers' productivity.
"These preliminary findings indicate that green buildings may positively affect public health," the researchers wrote in the study (.pdf), which was published in the American Journal of Public Health.
LEED, of course, is the ratings system ("Leadership in Energy and Environmental Design") issued to green buildings in the U.S.
In the first case study, 56 people moved into a LEED Platinum-rated building, and in the second, 207 people moved into a LEED Silver-rated building.
The researchers found that the move to green buildings:
- Lowered the average time at work that employees suffered from depression and stress from 20.21 to 14.06 hours a month.
- Decreased the average work hours per month that asthma and respiratory allergies affected workers from 16.28 to 6.32 hours.
- Cut the average number of hours per month an employee reported being absent per month because of asthma and allergies from 1.12 to 0.49.
- Reduces self-reported absenteeism from stress and depression from 0.93 hours per month to 0.47.
Most telling, employees thought that the environment of a conventional building actually depressed their productivity by 0.80 percent. In contrast, they felt a LEED-certified building raised their productivity by 2.18 percent.
The researchers -- Amanjeet Singh, Matt Syal, Sue Grady and Sinem Korkmaz -- said the LEED buildings offered a small benefit to employees who suffered from asthma and respiratory allergies. Without the need to call out sick, those people were estimated to gain 1.75 more work hours per year working in the new building.
(It should be noted that the survey did not track whether employees actually did stay out sick more often after moving to the new building; moreover, the two case studies were conducted at different times of the year, which could have seasonal impact to perceived sickness.)
But perceived productivity showed the biggest boost. According to the researchers, employees could each work about 39 more hours a year in the new building thanks to better light, air quality and ventilation.
The researchers said they plan to continue seeking funds to monitor participants of the study, as well as conduct more of them at different locations.
Photo: MSU's LEED Silver-certified chemistry building. (MSU)