Seattle City Light's resource for 
Part of the Lighting Layout Guide series: Control Guide 3.
As energy codes and energy efficiency goals become more demanding, there is a need to maximize energy savings from commercial lighting systems. While traditional lighting control strategies can yield considerable benefits, LLLCs show promise of deeper savings. It is no longer enough to have lighting in a large area be either ON or OFF, it must adapt to individual needs in response to changing occupancy, daylight, desired light level, and external energy grid conditions. A General Services Administration (GSA) study indicated that the typical office worker is away from their desk half of the time, if this vacancy can be captured, then energy savings can be maximized.