Building occupants who work in green buildings are more productive than those who work in nongreen buildings, according to a new study from the University of San Diego's Burnham-Moores Center for Real Estate and CB Richard Ellis. Researchers defined green buildings as those that are Leadership in Energy and Environmental Design (LEED) certified or those that bear the Energy Star label.

More than half of respondents either "strongly agreed" (12 percent) or "agreed" (42.5 percent) that employees were more productive in green buildings; 45 percent noted no change in productivity.

In addition, 45 percent of the respondents reported experiencing an average of 2.88 fewer sick days at their new, green office location. An equal amount noted no effect.

Green cleaning is a requirement in LEED for Existing Buildings: Operations and Maintenance certification. Green products contain fewer volatile organic compounds (VOCs), which contribute to poor indoor air quality.