The standard for energy efficiency in commercial buildings is the joint creation of two organizations: ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers) and IES (the Illuminating Engineering Society). The latest version of this standard, which is updated every few years, was released earlier this month. It sets much more stringent requirements for building envelope, lighting, mechanical and energy cost budgets.
The lighting standard focuses mainly on controls and daylighting. There are new space-by-space lighting power density limits (maximums for installed power over a defined area) and thresholds for top-lighting (bringing daylight into a space from the ceiling or roof). The goal is to achieve greater energy savings without impairing the quality of lighting for occupant satisfaction and comfort.