Washington, D.C.

Like a beacon, the dynamic glow of the illuminated corner building on Rhode Island Avenue points to a bright future for area residents. The Watha T. Daniel ' Shaw Neighborhood Library (Shaw) was one of the first projects in an ongoing D.C. Public Library initiative to build new facilities with community-friendly spaces and state-of-the-art information technologies. The mandate also stipulates that the buildings meet or exceed LEED Silver certification.

According to Peter Cook, Davis Brody Bond principal in charge of the Shaw Library project, light'in particular daylight boosted by electric light and controls'was a significant part of their energy-saving design strategy. The architects took advantage of the unobstructed, triangular site's potential for daylight by devising a three-story, 22,000-square-foot steel-frame structure with a 3-foot-deep overhang and perforated aluminum screen to shield the glazed, double-height reading room on its south side. Clerestory windows and translucent, insulated fiberglass panels on the north assure ample illumination from the sun on all sides, minimizing the need for electric light in the main reading room by day.

'The screen satisfies an important need to control the glare,' says project manager Christiane deJong. 'Lighting a reading space with mostly daylight is somewhat unusual.' The architects collaborated with the D.C.-based lighting design firm MCLA to validate what might be perceived as excessive light levels in the large, open room through a detailed analysis. Once the lighting designers determined there was no cause for concern, they developed an electric lighting system based primarily on the T5 linear fluorescent with a 3500-Kelvin color temperature'the lamp preferred by the client for energy and maintenance efficiency.

'The advantage of the T5 is, because it is narrower in diameter [than a T8], you can build a smaller reflector around it, which allows you to do smaller fixtures,' says MCLA senior designer Frank Feist. So, using T5s, they cantilevered special fixtures from the tall stacks for vertical illumination on the books, and suspended luminaires over reading tables and workstations. Then they installed slim T5 fixtures on top of exposed girders and the carrels under the clerestory windows for ambient uplighting that provides a luminous lantern effect and also reduces excess exterior lighting.

The D.C. Public Library is now specifying translucent structures for future projects, notes deJong'a clear indication that the Shaw measures up.