Preliminary Study Supports LEED Productivity Benefits
A new peer-reviewed study from Michigan State University researchers lends rare quantitative support to the idea that green building can lead to greater worker health and productivity. The study has several limitations, however, and the researchers characterized its results as “preliminary.”
Researchers focused on the approximately 250 employees of two different Lansing, Michigan, companies that were in the process of relocating from older, conventional offices to new, LEED-certified headquarters (one Platinum, one Silver). Employees answered questions about their perceived productivity, absenteeism, health, and overall well-being in two rounds of Web surveys, one pre-move and one post-move. (One of the study’s limitations is that for one building, the “pre-move” survey was conducted three months after the move, with subjects asked to recollect life in the old building. For this survey, data was removed for respondents who gave a poor rating to their own confidence in their recollections.)
The results indicated substantial improvements in all areas surveyed, including hours absent for asthma and allergies, work hours affected by depression and stress-related conditions, work hours affected by asthma and allergies, and productivity separate from those health issues. The study pointed to a benefit of over 40 work hours per year per occupant due to health and indoor environmental quality improvements (see table).
The authors of the study, published in the American Journal of Public Health, acknowledged several other limitations. It was not possible, for example, to eliminate the influence of perceptual bias in the self-reported results—the authors would have preferred to observe behavior directly. Seasonal factors contributing to the prevalence of asthma and allergies (the surveys were taken at different times during pollen season) could not be controlled.
Also, there was not a “control” for the study that would compare the effect of moving to the LEED-certified building versus moving to a new, non-LEED building. The authors cite this potential for temporary bias resulting from a change in the work environment as the “Hawthorne effect,” but they reference several studies that dispute whether such an effect really exists. The authors called for future research on larger sample populations in all seasons to support their work. The results can be viewed online; search for “Effects of Green Buildings on Employee Health and Productivity.”
– Andrea Ward