35 Hudson Yards – Structural Engineering

This mixed-use skyscraper is located at the heart of Hudson Yards, an unprecedented real estate development constructed above active railroad tracks and tunnels on the West Side of Manhattan. Reaching a height of more than 1000 feet, 35 Hudson Yards is the tallest residential building in the new district.

SOM’s integrated team of architects and engineers met the challenge of building 35 Hudson Yards on a platform above the tracks serving Penn Station, with no direct concrete connection between the tower and solid ground. The tower’s structural system consists of a high strength reinforced concrete core supplemented by a series of buttress walls that extend to the building perimeter. A key consideration was aligning the tower's structural system with the infrastructure below. In the east-west direction, the core walls align with the limited space available between train tracks, while in the north-south direction, the core spans 50 feet across three tracks. The tower’s structural columns align with the steel columns that support the platform.

By using high strength concrete at various grades, the team was able to limit the thickness of the building’s structure, lighten loads on the platform, and create smooth transitions as the tower rises in a series of setbacks. The building’s residential, hotel, and office floors are designed with reinforced concrete two-way flat slabs, a standard construction method that allowed this unconventional project to be completed on an accelerated schedule. The design team coordinated with the contractor to enable a two-day construction cycle on residential levels, using prefabricated elements such as wall reinforcement cages and high-strength rebar assemblages. While the tower’s overall footprint aligns nearly perfectly with the platform below, sloped columns negotiate the gap between support points where the tower’s massing recedes.

35 Hudson Yards is a classic example of what is possible when an integrated team works together to find innovative solutions to complex challenges—a constrained site, compounded by the need to maintain nonstop operation of critical infrastructure below. During construction, SOM maintained daily site visits to facilitate greater coordination between architectural, structural, and construction teams.