Joseph Provenza
WSP, New York City

The evolution and growth of cities and urban environments is a delicate balance between old and new. New structures and increased densification are carefully interwoven with existing infrastructure and buildings. As modern buildings reach new heights so does the embodied energy of creating such structures, highlighting the need for a more sustainable approach to building. Specifically, the question at hand is how can existing structures be extended upwards capitalizing on existing conditions at the same time minimizing disruption of the urban fabric?

Hudson Commons is a 700,000 square-foot (65,032-square-meter) renovation and addition in New York City which tackles this exact question. Situated at the gateway to the Hudson Yards submarket, this repositioned office tower maintains the expression of the preexisting site and scale of the neighborhood while attracting tenants to its Class-A workspace. An existing eight story cast in place concrete structure is extended vertically with the addition of seventeen floors of new steel. Specific engineering complexities of this aggressive repositioning include shoring free demolition for a new reinforced concrete core—providing lateral stiffness for the old and new structure, column retrofitting with shotcrete, foundation retrofitting, reconciliation of different column grids in the new and existing structures, and reinforcement of the existing structure to accommodate a new green roof. The possibilities for articulating existing structures into new buildings are expanding.