A four-hour drive from Mexico City's raucous sprawl, the city of San Luis Potosi, capital of a Mexican state of the same name, today is the kind of place destined to take up a spare paragraph in a tourist guide. Founded in the mid-1500s as a Franciscan mission, it boomed as a mining town in the following centuries, making it a key stop on the El Camino Real—the royal highway cutting across Mexico. The historic downtown illustrates San Luis Potosi's colonial richness: domed churches crowned with bell towers, stately governmental edifices, and grand plazas. But the intervening decades and the city's growth as a modern industrial city shifted its focus, leaving the Baroque architecture to the occasional tourist.

When architect and lighting designer Gustavo Avilés, founder of Mexico City–based Lighteam, visited San Luis Potosi in 2004, charged by the secretary of tourism to develop a master plan (the firm received the commission because of their experience lighting historic buildings), Avilés was shocked at how the city's architectural heritage had been diminished by utilitarian lighting, specifically low-pressure sodium lamps. “The city was invaded by informal markets—people gathering in the plazas without permits to sell their goods—and everything was bathed in a yellowish dark light,” Avilés recalls. “Because of the glare, all you could see was the lamps shining against your own eyes. You couldn't see the city at all. As we started to change the lighting to compact fluorescent and color-corrected luminaries, the city started to change. You could see the green in the trees, the color of the wood.”

Illuminating the historical city was critical, but Avilés wanted to make the treasures of San Luis Potosi visible to the whole of Mexico and the outside world. “The city was protected by time and distance,” Avilés continues. “It was protected by its own geography. This project is not just lighting, but identity. It is about recovering history and memory.”

Today, Lighteam is halfway through its six-year plan to transform San Luis Potosi, a task that comprises more than two dozen historic structures and nearly a half–million square feet to date. This past December, it inaugurated the third, and largest, phase: relighting Plaza de Armas, Plaza Fundadores, Plaza San Juan de Dios Templo, and 12 adjacent historic gardens and buildings. Plaza de Armas is the city's main square, home to both the Government Palace and a cathedral dating from 1718. Here, and across the historic center, Avilés' strategy reverses typical urban lighting approaches—lamps on poles. Rather, all wiring is underground, and the architecture is luminous. The cathedral glows theatrically: 2.5W light-emitting diode (LED) fixtures and 50W in-ground halogen floodlights bathe the intricate façade. A mix of metal halide flood lamps and fluorescent fixtures are installed within the Baroque bell towers. By using fixtures aimed at or on the buildings, his design not only accents the monumental architecture, but also uses the same fixtures to dramatic effect, creating ambient light in the surrounding public spaces.

In creating this master plan scheme, Avilés chose architecture with cultural, governmental, and religious significance not solely to increase tourism—although the redesign has bolstered that aspect of the city's activity—but also to evoke civic and spiritual meaning. For example, he placed 70W metal halide luminaires behind the cathedral's stained glass windows so that light would radiate from inside the church—a symbol, according to Avilés, of the knowledge within.

Secular buildings are treated with equally poetic sensitivity. The delicate architecture of the House of Culture—rose-colored walls, intricate tiles, and filigreed decoration—inspired what Avilés calls a “feminine” design. To highlight the handcrafted façade, he placed a combination of luminaire types—LED fixtures in a variety of wattages, 13W and 54W fluorescents, and 54W metal halides—away from the building structure, with a similar combination concealed in the balustrade and balcony.

With the Plaza de Aranzazú, Lighteam responded to the space's use to craft a lighting scheme. Flanked by the 17th-century Aranzazú Chapel and by a historic arcade—the remains of a Franciscan convent—the plaza is an active gathering space for young people who amble by the fountain and gather under the archways. Recessed into the paved surface and edging the plaza's perimeter under the arcade, 5W fluorescents uplight the arches, giving a rich dimensionality to the space that if underlit would feel gloomy or even dangerous. Recessed 50W and 90W metal halide lamps also are used to illuminate the ochre-walled chapel. Fixtures with 54W fluorescent lamps are integrated into the chapel's dome. “The new lighting makes the use of the public space a daily event,” Avilés says, noting an indicator of the project's success. “People have been meeting in the plaza with their girlfriends and boyfriends.”

Early in the process, Lighteam's master plan met with some opposition, mainly from the municipality's stable of engineers. Used to taking a conservative, technical approach to street lighting, they were dubious of an ambient scheme. When the luminaries initially were installed, the public also was skeptical. “When we opened the first plazas, people thought they were very dark,” Avilés explains, “because when you are used to brightness, you think that glare is light.” But an extensive set of illumination measurements, conducted by Lighteam, proved that the light levels were either the same as before or, if lower, still within an acceptable 1.5 footcandle range. What surprised both the designer and San Luis Potosi officials is that the data showed a huge drop in energy consumption—by an astonishing 50 percent. “Technology needs to be met, but there is also a social commitment,” Avilés reflects. “A good project has to use the best technology, create energy savings, and respond to issues of sustainability. That is a must, but it also has to work in reality. My approach is to look to the people and give them back something that was lost.”


PROJECT | Lighting master plan of San Luis Potosi, Mexico
CLIENT | Secretary of Tourism and the Government of the State of San Luis Potosi, Mexico
LIGHTING DESIGNER | Lighteam, Mexico City
PROJECT SIZE | 45,000 square meters
LIGHTING COSTS | $2 million (U.S.; approximate)
WATTS | 1.5 watts per square meter
PHOTOGRAPHER | Silvia Marquez, London
MANUFACTURERS | Brilliant, Contrulilta, iGuzzini, Meyer, Osram, Philips, Prommsa, Selux, Sill, Tecno Lite, Terrane, Ushio, Ventor