This luxury residential condominium on Manhattan’s Upper West side, situated near a busy subway station, is a 270,000- sq-ft tower with 131 units, three stories of residential amenities, three new retail spaces and a grand residential lobby on the ground level. In the cellar and subcellar are an Olympic-size travertine saltwater pool and spa, sauna and steam rooms, squash and basketball courts and other amenities.

The team erected a composite steel and concrete substructure and a 25-ft by 75-ft steel frame structural cantilever on the fifth floor, which supports 18 additional floors above an adjacent building housing a restaurant.

To erect the cantilever, the team had to extend a section of the building beyond its main structure to create an overhang. Then crews erected steel falsework atop a temporary platform to allow for installing the cantilever’s permanent steel at a 45 degree angle.

The team tied the steel cantilever into the building’s concrete structure using strap beams that formed composite action to help create a strong material bond, making the structure act as a single unit while optimizing the size of the 18 residential floorplates that are above it.

The cantilever is directly across the street from the 96th Street subway station, which introduced many complexities and required special coordination with the Metropolitan Transportation Authority along underground tunnels beside the jobsite property line. Vibration monitoring took place around the clock daily, and the team coordinated construction with the MTA inspector daily, focusing on a two-week advance schedule. The team stayed in close communication with the agency throughout excavation and foundation to avoid any disruption to operations from work involving machinery or cranes or utility installations.

To help the project finish at budget and on schedule in nearly three years, the construction manager financially incentivized subcontractors to provide quality management during all phases of construction.

Women held a significant number of construction roles on the project, including making up its construction management team and serving as labor foremen.