Ballard Library, Seattle

The new Ballard Library of the Seattle Public Library system pays homage to the neighborhood’s Scandinavian and maritime roots. The daringly sleek structure with soaring roof and 7,000-square-foot glass curtain wall also has won kudos for being on the vanguard of environmentally friendly construction. The 18,400-square-foot building, which opened in May 2005 and cost $10.9 million, was named one of the top 10 green projects in 2006 by the American Institute of Architects Committee on the Environment.

One of the most striking eco-elements is the 18,000-square-foot sod roof system with more than 13,000 plants, designed by American Hydrotech of Chicago. Another cutting-edge technology is the 400-square-foot curtain wall section made of ASI THRU photovoltaic glass, manufactured by Schott Solar of Germany, marketed in the United States by Schott North America, Elmsford, N.Y. The 11⁄4-inch insulating units consist of 1⁄4-inch outer glass with 1⁄8-inch ASI film-coated glass laminated between two PVB layers, 1⁄2-inch air space, and two 5⁄32-inch laminated inner glass panes. The units, positioned along the semicircular southwestern portion of the curtain wall, absorb different amounts of light throughout the day that gets fed back into the city’s power grid. The building was designed to bring natural daylight deep into the structure, minimizing the need for electric lighting. Photo sensors ensure that lights are dimmed or turned off when there is sufficient daylight.

Glass in the remaining curtain wall consists of 1-inch Solarban 60 units with 1⁄4-inch outer glass, 1⁄2-inch air space and 1⁄4-inch clear interior glass, manufactured by PPG Industries Inc. of Pittsburgh, fabricated by Northwestern Industries of Seattle and installed by Pacific Glass of Renton, Wash. Efco Corp. of Monett, Mo., manufactured the curtain-wall frames. The general contractor was the Seattle office of PCL Construction Services, Denver.

The project merged community interest in green design with the library’s desire to reach out. “Libraries are always thought of as depositories of knowledge, but we wanted it to be more of a learning and interactive experience,” says Robert Miller, architect, Bohlin Cywinski Jackson Architecture, Seattle office. Visitors can view voltage meters that display output from the windows and look through a periscope to view the roof.