Illuminating an Architectural Gem – 10 South LaSalle, Chicago
Grant Kightlinger, Senior Lighting Designer
This exterior lighting design project hit close to home – literally!
Nestled at 10 South LaSalle in downtown Chicago, a striking cobalt blue 1986 modernist office tower stands as the current home to AEI Chicago and Pivotal Lighting Design. This architectural marvel seamlessly integrates lower levels that showcase the historic façade of the once-standing Otis Building, originally designed by Holabird & Root in 1913. The marriage of these contrasting elements, old and new, culminates in the building’s 4-story entry alcove. Despite the grandeur of its design, the alcove had fallen into disrepair due to a dated lighting system and strained maintenance accessibility. A significant portion of the original mental-halide floodlights had ceased to function, rendering the space dark and somewhat uninviting.
In close collaboration with the building owner, Pivotal developed a new, refreshed lighting approach that revitalized the space yet preserved the building’s distinctive architectural charm – all the while remaining budget-friendly and non-invasive. Drawing inspiration from the building’s iconic cobalt blue finish, Pivotal introduced a saturated blue light to the alcove interior, illuminating the once-dark corners and accentuating the space’s height. At street level, the integration of warm white downlighting fosters a gentle and welcoming transition from the street to the lobby, instilling a sense of security and addressing one of the client’s key priorities.
A central design goal was to honor the captivating juxtaposition of the historic façade against the contemporary tower. In thoughtful execution, the blue lighting was strategically confined within the modern segment of the alcove, allowing the Otis Building’s façade to bask in the warm glow of the nearby high-pressure sodium street lights.
After finalizing the lighting design concept, a new challenge emerged: the varied layers of light and differing throw distances within the alcove necessitated a dimming control system. The system would enable independent adjustment of each horizontal fixture layer to achieve a harmonious final composition. However, the existing lighting system lacked dimming capabilities, comprising three circuits vertically arranged along each bay of the façade.
To circumvent the expense of installing new wiring and conduit to the fixtures, Pivotal leveraged existing fixture locations and specified a control system that embeds digital dimming and zoning information into the power supplied to the fixtures. This approach allowed the grouping and control of lighting layers without the need for re-circuiting. Additionally, a new front-end control system was integrated, featuring an astronomical time clock to automate lighting modes on a preset schedule, maximizing usability and reducing energy consumption year-round.