Case Study:
Bronx Library Center

Let the Sun Shine In: A light-filled library becomes a dynamic meeting place for an underserved community

By - Russell Fortmeyer

The sidewalk in front of New York’s new Bronx Library Center is a good eight feet wider than the rest of the block, all the better to accommodate the crowds of people who have flocked to the building since it opened. Elga Cace served as head librarian for nearly 25 years at the original building down the street. “It’s time the Bronx had something like this,” she says, referring to five floors now jam-packed with people flipping through books, checking e-mail, and engaging in boisterous conversation during a brisk fall Friday evening.

New York–based Dattner Architects intensified the community aspects of the 78,000-square-foot, $50 million building by centering its design around a four-story-high-performance glass curtain wall that fronts East Kingsbridge Road, just steps from the Bronx’s busy Fordham Avenue shopping district. Reading areas are positioned along the curtain wall in a 16-foot-wide structural cantilever, resulting in a display of people that makes the building look more like a busy retail store than a traditional library.

“When we built this building, it was so open there was some question of how [it] would be received,” says Dattner principal Daniel Heuberger, AIA. With that question answered handily by the mobs of people, Heuberger explains that achieving the openness without sacrificing energy efficiency was no accident.

The glass has a U-value of 0.39, relatively low and better than most dual-pane windows. A custom-integrated light shelf, with a built-in indirect fluorescent strip light, reflects the east-exposure morning light up to a vaulted ceiling that in turn forces daylight deep into the building’s interior. Translucent nylon mesh mechanized shades, integrated into the wall system, manually operate at each floor’s service desk. “When you have material assemblies that combine different building trades, you have to be very good about coordination,” Heuberger says.

Ceiling-mounted photocells on every floor track lighting levels. They dim the compact fluorescent downlights along the glass and control bilevel switching at the fluorescent direct/indirect lights that hang over book stacks. Seventy-five percent of the spaces meet LEED’s minimum criteria for the ratio of daylight to illuminated light, and the effects of the daylighting scheme make the interior seem much brighter than the building’s low lighting power density of 1.3 watts per-square-foot would suggest.

For the main reading room on the fourth floor, the architects wanted to “peel back” the ceiling up to the fifth-floor mezzanine to create a west-facing clerestory that would let late-afternoon sun flood the two floors. The swooping ceiling and roof element crown the building, establishing what Heuberger considers the library’s claim to civic landmark status.

The library—the flagship for the Bronx’s 34 branches—sits one block south of the home of Edgar Allan Poe and a block west of the original Fordham Library, which was a dark, technologically outdated building a third of the size of this one. A Con Edison utility building previously on the site was torn down; 80 percent of it was recycled, with the remainder sold to scrap dealers—an arrangement that paid for the cost of demolition. The property was excavated for a full basement that includes a 150-person-occupancy auditorium, conference rooms, and computer classrooms, as well as a large gathering area that brings daylight from an open stairwell to the ground floor. The artist Iñigo Manglano-Ovalle’s “Portrait of a Young Reader,” a work of colored glass cylinders mounted on steel backing, sets off the staircase and links the two floors.

Elevators and a main stair are situated at the back and west side of the building (the stairs are clad in a frosted channel glass, lending privacy to the apartment buildings surrounding the library), and offices and support spaces are positioned along the west and north sides. In addition to the auditorium, community groups can reserve meeting rooms on each floor; eventually, public events will also take place on an outdoor terrace on the south side of the third floor. Minimal use of finishes in these areas contributes to the consistently open feeling of each floor. The architects wanted spaces and materials that were easily recognizable by patrons: The exposed wood for casework is a lightly finished FSC-certified maple; rough Minnesota red granite used on walls was water-treated to bring out its color; the elevator core is bright blue; and a maple veneer was applied to the main reading room’s metal ceiling system. More than 55 percent of the building’s materials were sourced within 500 miles.

Mechanical rooms on the roof include air-cooled chillers and stacked air-handling units (AHUs), supplemented by boilers in a basement room. The decision to use air-cooled rather than water-cooled chillers was made after a series of conversations among the architects, client, and the project’s mechanical engineer, David Peterman, of Robert Derector Associates. “With air-cooled chillers, there’s no possibility of freezing, no loss of water, no plumes of moisture or chemicals, and less maintenance,” Peterman says. And although a water-cooled system’s cooling towers are typically more efficient, acoustical concerns, in addition to space requirements, ultimately led back to air-cooled chillers.

Other mechanical system features include high-efficiency filters and economizer modes for the AHUs, variable-speed drives for pumps, and compressors rated less than 15 horsepower so the library wouldn’t have to hire more expensive licensed operators. Altogether the library’s systems are designed to use 18.2 percent less energy measured against an ASHRAE Standard 90.1-1999 baseline.

Pat Konecky, a project manager with the New York Public Library’s Office of Capital Planning and Construction, says the embrace of sustainability when design began in 2001 represented a departure for the library system. “Sustainability wasn’t in the front of people’s minds when this project started,” she says. “Now, it is something we consider for every project we do.” Konecky also says the library’s design success has encouraged maintenance staff to do a better job of keeping the building up, even though they needed more extensive training to operate the building’s complex mechanical control systems. And Steven Winter Associates, the library’s sustainability consultants, have returned to provide additional commissioning during the first year of operation. “This has resulted in better-functioning equipment,” Konecky says, noting that the additional commissioning has revealed only minor problems.

If the library’s daylighting success overshadows the subtler sustainable characteristics of the project, no one seems to mind. The library system intended to build a resource for a community, not necessarily a high-performance sustainable building. Michael Alvarez, the new head librarian, has worked in nearly 25 libraries in his career, but none have been as inviting as the Bronx Library Center. “Most are very similar to one another,” he says. “But the light-filled feel of this library was so radically different, I had to apply for this job.”

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