When asked to design a lighting scheme for the already-completed 316-seat auditorium in Barcelona's Agbar Tower, Martin Architectural's Spanish representative ECLER had to follow in some dauntingly large footsteps. French architect Jean Nouvel's 35-story tower, with its elliptic plan and domed top, resembles not so much a traditional skyscraper as a force of nature. In Nouvel's words, the tower is "a fluid mass that bursts through the ground like a geyser under permanent, calculated pressure." A fitting metaphor considering the building's primary tenant, the Agbar Group, is Barcelona's water company. The tower's skin continues this hydrological reference, featuring thousands of colored aluminum sheets and tinted glass louvers that create a shimmering range of coppery reds to cool blues, meant to resemble an iridescent film floating on water. At night these colors are picked up by a computer-controlled system of 4,500 RGB LEDs designed in collaboration with celebrated lighting artist Yann Kersale. Nouvel expected the auditorium lighting to embody this same level of invention. ECLER project manager Antonio Tejerina explains, "The exterior illumination of the tower was revolutionary; and the auditorium had to be revolutionary in terms of what lighting can provide."

While the architects wanted to create a degree of correspondence between the exterior and auditorium lighting, such as maintaining the colorful effect, the concept behind each is quite distinct. "By day, the exterior lighting relates to the real colors of the facade," explains project manager Jean-Pierre Bouanha of Ateliers Jean Nouvel. "Meanwhile, the auditorium lighting had to permit the possibility of changing the colors and the intensity of light depending on the function taking place in the auditorium, whether it's a lecture, meeting, or projection. The lighting had to be very flexible."

To provide versatility for a range of lighting needs and a diverse color palette, ECLER chose a system of fluorescent luminaires that employ RGB color mixing technology. Each fixture, in a slim housing, combines three, 28W T5 lamps controlled by a remote DMX dimming system. "By dimming each lamp differently you get the end color, a mix of colors, or any temperature of white, depending on the need of use," says Tejerina.

Nouvel also wanted the auditorium's lighting to fit seamlessly within the space and generate the desired effect without calling people's attention to the fixtures themselves. Since the auditorium was already finished when ECLER received the commission, the challenge was to find a discreet way to integrate their system within the defined envelope. In the end, ECLER and Nouvel located the luminaires--90 in all--in coves at the juncture of walls and ceiling, and walls and floor. From these positions, the fixtures wash the stainless-steel mesh walls--which act as reflectors--from above and below, radiating color and light throughout the auditorium.

The space features other light sources that were in place when ECLER began its work; downlights in the ceiling for general illumination and emergency purposes. But, Tejerina says, 80 percent of the time, once everyone using the auditorium is in and seated, their system provides all of the required ambient illumination, whether users are watching a film or taking notes at a lecture. With the right technology and application, lighting can break the boundary between decoration and service.


project | Agbar Tower Auditorium, Barcelona
design team | Ateliers Jean Nouvel, Paris with b720 Arquitectos, Barcelona (architects); ECLER, Barcelona (lighting consultant)
project size | 550,000 square feet (building)
photographer | Allan Toft, Aarhus, Denmark
manufacturer | Martin Architectural