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Bicentennial Pavilion and Promenade at Indianapolis Zoo

Photo: Susan Fleck Photography
Photo: Susan Fleck Photography

RATIO Architects Inc. modeled the Bicentennial Pavilion and Promenade at Indianapolis Zoo after an Indiana forest. Each of 11 tree-like pods has 63 wood beams, a weathered steel rainscreen and translucent roof panels. The wood beams range from 83 feet long and 19,000 pounds to 3 feet and 25 pounds. The forest of pods is held together with 6,424 bolts and lag screws.

The canopies vary in height to increase air circulation along the promenade. Beneath the 35-foot canopy, a hearth of rough-back quarry block limestone serves as a visual centerpiece and provides warmth during cold weather. The pavilion’s 40,000 square feet of open air event space has seating for 1,000 visitors.

All pathways in the zoo connect to the pavilion’s central placement, which improved circulation through the zoo. Andrew Heilman, architect at RATIO Architects, says, “The previous layout was essentially a maze that was confusing for visitors. This structure has cleaned up the circulation space around the zoo by making more accessible paths that all tie together. Now when you visit, it’s practically a guarantee that you’ll visit the pavilion at some point.”

For daylighting, the project used 12,770 square feet of Kingspan Light + Air LLC’s (formerly CPI Daylighting) U-Lite low-slope canopy system. The U-Lite system channels water to a drainage system, where it is collected from the pods by a weathered steel structure and moved to plants below the canopies. Each canopy utilizes a combination of clear and ice white glazing panels to provide a balance of diffused and direct light. Rainwater is primarily collected on-site and percolates into the aquifer, reducing discharge to city sewers.

“Because the design of the panel is turned up at the end on all four sides of each pod, there are no moisture problems and water can efficiently drain,” Heilman says.

When water contacts the canopy, it is funneled into the pods, down rainscreens of custom, laser-cut, weathered steel to a sunken, plant-filled bed below, through a water quality unit and to a 14-foot-deep water detention bed of free draining stones, designed to accommodate 100-year flood events. Within each bed are plants that thrive in saturated environments and water intake pipes that are raised above grade to encourage natural percolation through the soil.

The project utilized 157.032 tons of Lenex Steel Co.’s A588 weathering steel and 6,000 square feet of 1/4-inch A588 weathering steel laser cut panels. Poynter Sheet Metal was the fabricator.

The Bicentennial Pavilion and Promenade’s forest-like environment provides a location for the zoo’s bird exhibition, Magnificent Macaws, with a custom stage and perch. The project was funded by a $10 million grant from the Lilly Endowment and was completed in June 2017.