January 2009

---

How Daylighting Can Improve IEQ

By Mike Molinski, LEED AP

The Heschong Mahone Group, Inc., an organization that provides professional consulting services in the field of energy efficiency, found that office workers provided with a better indoor work environment, including daylight, an outdoor view and better ventilation conditions:

• Performed 10 to 25 percent better on tests of mental function and memory recall
• Were less likely to report negative health symptoms
• Worked 6 to 12 percent faster

According to a daylighting and work performance study by the California Energy Commission:

• Exposure to daylight was consistently linked with a higher level of concentration and better short-term memory recall
• Students in classrooms with the highest levels of daylight performed 7 to 18 percent higher on standardized tests

Students with the most daylight in their classrooms were found to progress 20 percent faster on math tests and 26 percent faster on reading tests over the course of a year.