trading floors are traditionally gloomy, stifling, windowless, and intense working environments crammed with professionals either scurrying about or enchained to desks. But Bank of America's (BoA) Charlotte, North Carolina, trading floor-winner of 2005 Lumen and IIDA Award of Excellence merits-defies such convention. Designed by the joint Manhattan-based team of Skidmore, Owings & Merrill (SOM) and Cosentini Lighting Design, this high-tech, high-performance facility both exceeds the financial industry's quality standards (a chair, table, and computer monitor) and conveys BoA's corporate identity. Re-imagining what a computer-age trading floor can be, the luminous 180,000-square-foot facility not only serves as BoA's vehicle for recruiting industry-leading traders from competitors in New York, Chicago, and San Francisco, it also provides the open, comfortable, and inspiring environment these traders need to excel in serving clients.

Trading floors, explains SOM interior design partner Stephen Apking, are places where financial institutions can realize enormous value by grouping as many personnel together as possible. Traders perform better when they have immediate access to other traders and information in other markets. This is accomplished by workstation arrangements and quality acoustics, as well as visually open, unobstructed spaces with nearby support areas. Because of this, the SOM/Cosentini team used an integrated systems approach (the space and lighting were created together) to resolve the extreme issues involved in designing this facility, which can house as many as 1,000 traders and which SOM associate partner Douglass Alligood calls surprisingly quiet. Of the many engineering feats executed to realize this project, none involved as big a leap forward, says Apking, as the lighting solution.

This facility's lighting story is about incorporating daylight, and managing its intensity, in an environment supporting both hundreds of computer screens transmitting global trading updates and hundreds of traders engaging each other within two trading arenas. What makes daylight illumination possible in contemporary trading environments, says Cosentini principal Stephen Margulies, are the recent advancements in monitor technology. Today's low-glare, high-contrast screens enable intensive use over sustained periods. Such technology allowed SOM design partner Mustafa Abadan to develop this five-story facility using a king-post truss, a bow-and-arrow-shaped system requiring less steel and fewer pieces than other truss types. The result is the column-free, 50-foot-high north trading arena, flanked on the east and west by glass-banistered mezzanines with support offices and conference rooms. It is separated from the smaller 35-foot-high south trading arena by the elevator core and escalators to the lower reception area.

Relocating the trading floor's mechanical equipment from the roof, allowed Abadan to incorporate clerestories-oriented north, east, and west-into each of the truss's bays, thus creating an interior aglow with indirect daylight. This setup also allowed Margulies to electrically backlight the ceiling's configuration of crumpled folds that reflect a mix of daylight and electric light, and thereby generate the required lighting levels for a trading environment. Moreover, the truss enabled Abadan to design a dramatic 100-foot-long, 50-foot-tall bronze-tinted Pilkington curtain wall in the north trading arena. The challenge here involved managing the quality and quantity of daylight entering the space. Instead of opting for screen-embedded or special tint-coated glass, the team selected motorized horizontal sliding shades with a 30 percent transmission. Shielding the north–south-arranged workstations from direct glare, this solution is programmed to coincide with the sun's year-round path, a schedule Cosentini developed from numerous in-depth studies of Charlotte's daylight in relation to the building's orientation of 20 degrees off true north. Margulies added sensors to safeguard against mechanical malfunction and to allow for manual control of the shading. During daytime hours, occupants prefer shades-up and lights-off to enjoy the abundance of daylight the facility garners.

The electric lighting solution generates a consistent, low-contrast illumination using direct and indirect sources, creating the setting traders need to repeatedly shift from looking at and away from their screens without eye fatigue. Margulies used direct and indirect sources in the trading arenas because, he explains, the indirect lights-one and two rows of T5 covelights concealed within the rim of the ceiling folds-alone would have flattened the space. The double row of uplights produces a redundancy that prevents gaps when bulbs burn out. Ceramic metal halide and PAR38 lamps function as recessed downlights; the ceiling's height diffuses their intensity, eliminating glare. This combination of sources creates multiple levels of light that accentuate the facility's structural features. It is a layout realized through careful planning: Cosentini tested the uplights on full-scale ceiling panel mock-ups and then programmed the single and double rows of uplights separately to manage the heat gain.

To the mezzanine's modular offices, Margulies attached mountable module lights to accommodate future spatial reconfigurations. To accentuate the mezzanine's function as a client receiving and meeting area, Margulies used spot and accent lights, which produce a boutique-style intimacy. It is a solution symbolizing the team's project intent, which Apking describes as designing from a minimum of means, preferring not lavish materials, but those that express the necessary. To realize this idea in the lighting, Margulies programmed the electric lights and the motorized shades to create a setting textured with luminous richness. He was able to commission the entire facility's lighting system in less than 12 hours, a relatively short amount of time given the size and scope of the project.

Equally impressive is the lighting solution's wattage calculation. Although officials initially told Margulies that there were no energy-code compliance issues, local inspectors later changed their minds: They wanted energy-code compliance documents-after construction was complete. Although the facility is lit primarily with fluorescent and metal halide sources, not incandescent, Margulies was concerned his plan would exceed code. In contrast to the many fixtures used in the trading arenas, only a few areas (support offices and conference rooms) were equipped with low-wattage luminaires. Twice his team calculated the wattage, twice they got the same answer: 1.5 watts per square foot. When Margulies measured the facility with a light meter to confirm the calculations, he discovered that during the day, when the electric lights are either off or set very low, and the space is primarily lit by daylight, the illuminance level dropped to 0.7 watts per square foot.

With a vision toward the future, the modulation of daylight balanced with electric sources creates a state-of-the-art trading facility. This allowed the design team to create an interior that suggests vibrant motion. It is also a prominent beacon on the city's skyline and a resplendent stage, visible from the surrounding buildings, upon which the traders publicly play out the daily dramas inherent in their profession. joseph dennis kelly ii