The Benefits of Daylighting
Daylighting is the illumination of buildings by natural light. Often achieved by proper interior and exterior design and advanced glazing, its aim is to dually maximize occupant comfort and reduce energy use. Daylighting in homes, workplaces, hospitals, schools, and commercial spaces can have multi-faceted positive impacts.
Proven Daylighting Results
The Heschong Mahone Group found that office workers who are provided with a better physical indoor work environment, including daylight, an outdoor view, and better ventilation conditions, were:
- Perform 10-25 percent better on tests of mental function and memory recall
- Less likely to report negative health symptoms
- Found to work 6-12 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 7-18 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
The overall objective of daylighting is to minimize the use of artificial light and reduce electricity costs, but it can also lower HVAC costs. Electrical lighting in modern buildings produces a lot of heat; if properly directed, though, natural lighting generates hardly any heat at all. In addition, the budgeted amount for electrical lighting, as well as heating or cooling loads and the amount of cooling required keeping a building at a specified temperature, can be redirected toward lighting systems and HVAC equipment.
For most buildings, the energy savings typically range from 15-40 percent. Although energy savings and sustainability may be the reasons companies initially opt for daylighting, it can have a significant, measurable impact on the productivity and satisfaction of tenants and occupants.
Even retail stores like Wal-Mart are beginning to see the benefits of daylighting for employees and consumers. In a test experiment, stores included skylights over certain departments and found that overall sales per square foot were higher in the departments that were lit by natural light.