Electric Lighting at the Bullitt Center

Posted by Nina Smith-Gardiner, AIA, LEED AP on Sat, Apr 06, 2013 at 12:00 AM

(C) Nic Lehoux

(C) Ben Benschneider

Daylight will illuminate the interior of the Bullitt Center for 90% of the time without the need for electric lighting. Keeping electrical lighting at a minimum to reduce energy use was a design driver throughout the process. The lighting design incorporates simple lighting controls: manual dimming, occupancy sensors, photocells, and plain old wall switches.

In some areas of the building an occupancy sensor turns the lights on and off, and in others the occupant switches the lights on and an auto control will turn them off. The circulation spaces use carefully placed wall washing light fixtures, which dim to 50% after a programmed time and then turn off after another set time, to guide people with areas of strong vertical illumination. The lighting in the stair area is monitored by an occupancy sensor, allowing the lighting to “follow” the person as they move up and down the stair, turning off the fixtures when the stair is unoccupied.

© Benjamin Benschneider

© Benjamin Benschneider

Tenant spaces will use task lighting to augment the daylight to keep the lighting power densities very low, with minimal need for ambient lighting. Occupancy sensor power strips located at each desk keep lights and computers off when the desk in unoccupied. Simple systems like this and “green switches” to turn off power to the floor at night help eliminate phantom load of systems that typically run all night. Occupancy sensors turn off emergency lights after hours and all external building entries have motion sensors so when there is no foot traffic the building can fall truly dark.

The core building control system is a DALI (Digital Addressable Lighting Interface) system, allowing flexible control of individual fixtures and modularity in the future expansion of the system. The lighting design was by Luma Lighting Design of Portland, Oregon. The use of electricity is carefully monitored and controlledthroughout the building through a circuit level monitoring system designed by the electrical engineers at PAE. This system will verify tenant energy use, as each tenant will have an overall energy budget incorporated into their lease.

Simplicity, clarity, and energy-efficiency: all themes found throughout the Bullitt Center, making it the remarkable building it is.