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In pursuit of transparency, architects use a lot of glass. But, rather than clarity, the result can be glare and reflection. This is what the lighting designers at New York–based One Lux Studio (OLS) wanted to avoid in the lobby of 320 South Canal Street, a 51-story office tower designed by Goettsch Partners for a West Loop site just south of Chicago’s Union Station.

OLS partner Stephen Margulies and architect James Goettsch, chairman and co-design director of his eponymous Chicago-based firm, have collaborated on 20 projects since they first worked together, more than 40 years ago. “We understand each other,” says Margulies. “Jim always wants the lighting to build on the architectural design and never the reverse.”

Goettsch has a well-earned reputation as an advocate for architecture’s civic role. “Both the interior and exterior ground-floor spaces are as important to the public realm as they are to the building’s occupants, and so we place an increased emphasis on their design,” he says. “When we design a lobby, we consider it to be part of the urban streetscape and the streetscape to be part of the lobby.”

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The 51-story tower (2) glows from discreet fixtures tucked into its ground-level ceiling plane, inside and out (1 and top of page), and throughout an adjacent green space (3). Photos © Nick Ulivieri, click to enlarge.

The core of the 40-foot-high space is articulated as faceted planes of saw-cut, sandblasted Carrara marble, visible from outdoors through a perimeter enclosure of clear glass. “Our goal was to light the white stone walls beautifully, evenly, and with no reflections,” says Margulies. To accomplish this, OLS recessed multiple clusters of LED downlights, with varied beam distributions and lens accessories, into the painted gypsum board ceiling, which is also faceted. The LEDs were pre-aimed during manufacturing to ensure a clean look and minimize aiming time during installation. A daylight sensor adjusts their brightness.

To avoid glare and reflection, Margulies and his colleagues recommended that the lobby’s fin-wall glazing system be made of zero-reflection glass, allowing unobstructed views from outside, where the building’s stainless-steel-clad exoskeleton meets the ground in V-shaped piers. These are discreetly illuminated from above by adjustable fixtures recessed into the folded ceiling plane, similar to those used inside.

The 10-foot-wide by 40-foot-high laminated glazing panels wrapping the lobby comprise three layers of glass, about 1¼-inch thick in total, fabricated in Germany, sent to New York by ship, and then to Chicago in specially designed trailers. An antireflective coating on both exterior and interior surfaces keeps the visible light reflectance down to less than 2 percent, while providing visible light transmittance of 89 percent. According to Goettsch, the coating did not add significantly to construction cost. But because this product is manufactured only once a year, it had to be fitted carefully into the schedule.

The artful combination of lighting and glazing provides a luminous backdrop to an adjacent 1½-acre green space, which is open until midnight. Organized around a large oval lawn surrounded by a curving path, this outdoor room glimmers after dark. LED “tape lights,” integrated beneath precast concrete benches, are augmented by “mini bullet” lights shimmering up into the foliage of lilac bushes and maple, birch, and spruce trees. But the real magic comes from high above: at level 31, a partially louvered mechanical floor, 24 narrow-beam floodlights with glare shields are secured to vertical members of the building’s curtain wall. These wash softly over the park, creating the ambient glow of moonlight.