New guidelines by the Illuminating Engineering Society of North America switches emphasis from quantity of light to quality of light. The focus is on how a space is used and by whom. The guide, IESNA Lighting Handbook, lists design issues, ranked by priority, for each type of space. The highest priorities when considered together help determine the best lighting for that space. For example, lighting in a company cafeteria should make the food look the way it is supposed to look and also provide good facial modeling, so that diners can read each other’s expressions.
The guide does not recommend using overhead lighting only, and emphasizes that lighting must come from several directions, with several sources. Part of the new approach to lighting is that users should not look only at energy consumption but view lighting as a means to define spaces.
Based on a report from Building Operating Management
