Strategy 2: Daylight controls for 50% of lighting load 

Daylight-sensitive controls work only with ambient space lighting—not task lighting, art illumination, or other forms of lighting.

Identify regularly occupied spaces in your plans that have windows where daylighting sensors can be installed within 15 feet. These include open and private offices, conference rooms, and cafeterias.

Strategy 1: Daylight controls for daylit areas

Incorporate manual overrides on both occupancy and daylight sensors into your lighting system design only when necessary. Manual overrides must be used with caution, and should only be temporary. Otherwise, the sensors may be overridden and forgotten, negating potential financial and performance benefits. 

Although integrated control strategies have additional cost up front, these systems can also tie into mechanical systems to significantly reduce energy use. 

Make sure that the owner knows about ongoing maintenance requirements for controls. Daylight sensors should be calibrated every 3–5 years to maintain the performance of the lighting control system. 

Dimming systems often cost more than stepped systems, but also have better performance and are less distracting to occupants when the amount of daylight in the space changes. 

Before the sensor system is designed, identify occupant lighting needs that can be met with daylight. Typical light levels in offices are 30–50 footcandles for most tasks. The Illuminating Engineering Society of North America (IES) prescribes footcandle levels for various project types, occupant types, and tasks. (See Resources.)  

Daylight and occupancy controls may be standalone or integrated into a central, intelligent lighting control system. It might take additional wiring and commissioning, but this type of integrated system is usually the most efficient.