Wherever people are involved in intellectual work or learning, it’s crucial to provide a supportive environment that keeps the brain relaxed, the mind alert and the body healthy. Research proves that natural light does just that.  In a 1999 study, students in the classrooms with most natural light progressed 20 percent faster on math tests and 26 percent faster on reading tests. Workforce studies show how productivity increases by typically 6-16 percent, absence decreases by around 5-25 percent. Add to this the energy savings of up to 25 percent of the annual costs and it’s not difficult to calculate a short time between investment and payback.