Published: March 3, 2016


The task of a lighting designer or engineer is to design a lighting system that provides just enough light for a building’s occupants to conduct their daily tasks. For instance, someone reading a book typically requires more light than someone walking down a hallway. The designer must generally err on the side of providing too much light rather than too little to avoid occupant complaints. Spaces can be over lit due to fixtures selection, lack of photometric analysis, or for aesthetic reasons. Today’s dimmable lighting systems allow building operators to reduce overlighting by task tuning the lights, adjusting light levels so that illuminance is appropriate for the activity in the space.

Good task tuning begins in the design phase by laying out fixtures with respect to furniture and occupant behaviors within the space. Once the lights are installed the lighting should be dimmed until the exact target light level is achieved. Task tuning has the highest potential for energy savings in spaces with long hours of operation, noncommissioned lighting systems, and systems designed by contractors. If dimmable lighting is already in place for daylighting or occupant comfort, then task tuning has a short payback of 0.5 to 1.1 years.

[1] Schuetter, S., Li, J., & Lord, M. (2015). Adjusting lighting levels in commercial buildings. Retrieved November 24, 2015, from

[2] Williams, et al. 2012. “Lighting controls in commercial buildings,” Vol. 8, No. 3, January 2012, pg. 161–180.