Arup Lighting

Washington, D.C.

Creating a space that inspires is a weighty responsibility for architects and designers. KieranTimberlake's 2000 master plan for Sidwell Friends School, a Quaker K'12 day school in Washington, D.C., called for updating, uniting, and optimizing an aging urban campus, reflecting the school's desire to become a model of sustainability. As part of its scheme, the Philadelphia-based firm renovated the existing gymnasium, transforming the 1950s structure into a hybrid Arts Center and Meeting House (actually a large room within the building) to be used for the students' weekly worship.

Gleaning from the philosophical and spiritual teachings of the Religious Society of Friends founder George Fox, the architects created a simple diagram that configures the space and materials around a core of silence and light. According to partner Stephen Kieran, this arrangement literally defines the room, so it becomes a magnet that draws everyone around it into its sphere, providing form, order, and meaning where none existed

Meetings take place in this seemingly simple space, where the architects devised an atmosphere of silence—both aural and visual—by minimizing elements that might bring participants back to the present. To do this they pocketed doors, worked exit signs into door frames, and tucked mechanicals out of view. Then they layered a series of floating white wall and ceiling panels around windows and a deep central skylight. These buffer noise, direct sunlight, and outside distractions, yet still reveal glimpses of nature. During the day, a gentle illumination filters in around the suspended vertical and horizontal planes that screen existing north and south clerestories, and the newly installed skylight, enhancing the warmth of the reclaimed white-oak flooring below—a rich, unfinished surface that continues up the walls and wraps the room.

Working with Arup Lighting, the architects maintained the quality of the sun's glow at night by installing indirect T5 fluorescent tubes. Each electric-lighting gesture can be controlled independently, as needed, to augment varying daylight conditions and specific programmatic requirements.

The designers used similar lighting techniques and suspended ceiling planes in the surrounding hallways, extending the illusion of skylights beyond the immediate Meeting House room. Nearly all the lighting in the public spaces, which includes PAR30 halogen lamps and Biax compact fluorescent channel and track lighting, is hidden from view, spreading the silence out to the campus beyond.

The entire space is lit using 1.9 watts per square foot, with 3,500K T5 high-output fluorescent lamps that achieve 25 to 30 foot-candles. The Arup designers used daylight analysis and lighting-simulation software to verify light levels. They tested multiple configurations, working with KieranTimberlake to make slight adjustments to the architecture in order to maximize the quantity of natural illumination entering the space. The final daylight-autonomy calculations indicate that most of the room achieves greater than 300 lux for over 50 percent of normal operating hours, lessening the need for supplementary electric light. Typically, during the day only cove lights at the east and west walls are necessary.

Given the volume and multiple uses of the space, the designers might have been tempted to introduce a variety of lighting systems. But they purposely kept their interventions spare and simple. The balance of electric light and daylight peeking between the layers not only yields a sense of serenity and calm that encourages contemplation, it reinforces the client's commitment to the environment and its student body.


KieranTimberlake — Stephen Kieran, James Timberlake, design partners; Jason Smith, associate in charge; Andrew Evans, project architect

Lighting Designer:
Arup Lighting — Brian Stacy, associate

CVM (structural); Bruce E. Brooks & Associates (m/e/p); Vika (civil); GeoConcepts (geotechnical)

K2 Audio (acoustic); GreenShape (environmental)

General Contractor:

Size: 4,200 square feet

Completion Date:
May 2011



Pinnacle (cove); Cooper (downlights)

Philips Strand Lighting

BASWAphon (acoustical plaster); Benjamin Moore (low-VOC paint)