Award of Merit - Cultural

New York Botanical Garden Visitor Center

An oasis in the concrete desert of the city, the New York Botanical Garden is an ideal place to behold the wonder of the natural world. It is not an ideal place for a construction site.

The awards jury recognized the extreme delicacy needed to build the 20,700-sq.-ft. Leon Levy Visitor Center while adhering to strict environmental regulations protecting the garden's 250 bucolic acres in the Bronx.

"It was the overall high quality of design and sensitivity to the work being done there," said a judge about the project's attraction.

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The entire job cost just under $14 million, with the visitor center opening to the public in May. Throughout the entire 18-month construction window that ended in January, the project team made protection of the garden's fragile ecosystems the top priority.

Contractors and garden officials ensured that construction would not harm the plant life by taking steps such as inspecting and monitoring all offsite backfill material to confirm that PH levels remained below 7.0 around existing trees. The team established zones barring work or traffic around specified trees and surrounding grounds, protecting both the above ground trunk and branches and the root systems below. Crews performed all excavation work in the protective zones by hand under the supervision of a Botanical Garden arborist.

Since the garden remained open throughout construction, builders had to respect the garden's visitors as they did the flowers and trees. Part of that effort entailed building an aesthetically appropriate, solid ornamental wood fence around the entire construction site. Similarly, in order to keep the entrance drive and parking areas clean outside the construction site, crews washed all construction vehicles leaving the fenced-in site to remove dirt and debris. All deliveries took place during hours when the garden was closed.

Beyond those adjustments, the construction team also faced site obstacles, including a pair of city water mains running parallel to each other beneath the construction site. The team designed a foundation system - utilizing timber sheeting and trench boxes - that worked around the 36-in. and 48-in. pipes.

In some areas, the site required deeper excavation for the foundation due to the presence of unsuitable soil. The construction team expanded a dewatering process to alleviate the presence of groundwater, which was at a higher-than-expected level during construction.

The design of the visitor center offered another challenge. It involved an extensive pedestrian walkway system to connect the multiple buildings, utilizing blue stone pavers.

The design called for 5-in. thick stones weighing approximately 500 lbs. each, installed with a zero allowable tolerance, or no joint between each stone. Normally, paving stone installation employs a strap wire or rope that is placed around the stone to set it but then removed through the joint. The zero tolerance requirement disallowed that method, so the project superintendent worked with the stone subcontractor to construct a scaffold rig to set the stone in place. The rig supported each 500-lb. stone utilizing an air compressor and suction cup.

That kind of innovative thinking allowed construction to be completed on time and on budget. The finished product includes three one-story buildings spread across 3.5 acres, featuring an entry loggia, café building, retail space, and rest rooms. The design of the structures incorporates arched, glued-laminated wood beams that follow the contours of the clamshell roofs, supported by exposed vertical structural steel members.

The result also pleased the client, judging from the comments of Gregory Long, president of the New York Botanical Garden, at the dedication ceremony. "We are thrilled to be dedicating the Leon Levy Visitor Center, which is architecturally distinguished, functionally appealing, and aesthetically consistent with the magnificent setting beyond its borders," he said.