SAN DIEGO -- Researchers at the University of San Diego's Burnham-Moores Center for Real Estate and CB Richard Ellis have found that employees who work in green buildings are more productive than their counterparts who work in non-green buildings. Green buildings were defined as those that are LEED-certified at any level or those that bear the Energy Star label.

In the study, researchers Norm Miller, Ph.D., academic director at the Burnham-Moores Center, and David Pogue, national director of sustainability at CBRE, surveyed 154 green buildings nationwide containing over 2,000 tenants, 534 of which participated in the study. The study is the largest of its kind by far; a 2003 study looked at productivity levels in just 33 green buildings. Miller and Pogue used two measurements of productivity: sick days and the self-reported productivity percentage change after moving into a new building.

Forty-five percent of respondents reported that they had experienced an average of 2.88 fewer sick days at their new, green office location vs. their previous non-green office location. An equal amount noted no effect, while 10% reported more sick days. The 10% that reported more sick days were residents of Energy Star-labeled, not LEED-certified buildings. Unlike LEED buildings, Energy Star buildings do not have air quality requirements.

Based on the average salary of the tenants, an office space of 250-sq.ft. per worker and 250 workdays a year, the 2.88 fewer sick days translate into a net impact of $4.91 per employee, according to the authors.

On the self-reported productivity measure, 12% of respondents said that they strongly agree that employees were more productive in green buildings, 42.5% agreed that employees were more productive and 45% noted no change in productivity. According to the authors' calculations, the increase in productivity translates into a net impact of $20.82 per employee, based on an office space of 250-sq.ft. per worker and using average salary as an index.

"Healthier buildings reduce sick time and increase productivity," says Miller. "If you consider the benefits in terms of recruitment, retention of employees, less sick time and greater productivity, tenants should be willing to pay more rent for such space or require steep discounts for less healthy space."

For the full study, go to www.usdrealestate.com.