270 Park Avenue: The Skyscraper Built Above Grand Central's Trains

At street level, 270 Park Avenue appears to rise on a handful of splayed steel columns. The effect is almost weightless: a 1,388-foot office tower hovering above Midtown.

Underground, the picture is considerably heavier.

JPMorganChase’s headquarters occupies a full block between Park and Madison avenues, but much of that land cannot support an ordinary foundation grid. Tracks and platforms serving Grand Central Terminal and Grand Central Madison run beneath all but the site’s western quarter. The tower therefore had to be designed around a two-level railroad complex that would remain in operation below it.

Where it is

270 Park Avenue
New York, NY 10017

First, unbuilding a landmark

Before the new tower could rise, JPMorganChase had to remove its former headquarters: the 52-story Union Carbide Building, completed in 1960 and associated with Skidmore, Owings & Merrill architects Natalie de Blois and Gordon Bunshaft.

Its Midtown surroundings and the infrastructure below ruled out an implosion. Beginning in 2019, crews enclosed the building and dismantled it methodically from the top down. Floors, framing and equipment were separated and lowered rather than dropped into the street. The approximately 707-foot building became the tallest structure intentionally demolished, and 97 percent of its material was ultimately reused, recycled or upcycled, according to Foster + Partners.

Removing the old tower did not produce an empty construction site. Its foundations, the train shed and immovable power and signal equipment still occupied the narrow spaces between tracks.

The “Tabletop” beneath the tower

A conventional skyscraper distributes its weight through a regular forest of vertical columns. At 270 Park Avenue, Severud Associates instead surveyed the slivers between trains’ operating envelopes, some no wider than about four feet, and identified only a few practical lines of support.

The answer was a two-story transfer structure nicknamed the “Tabletop.” Along the north and south sides, groups of exterior columns slope together into three enormous fans. Inside, V-shaped supports carry a pair of plate girders running roughly 360 feet through the building. These members collect loads from the much broader tower above and steer them toward the limited foundation locations below.

At their bases, the super-columns can impose loads approaching 100,000 kips on areas of only about 60 square feet. Engineers developed concrete rated at 16,000 psi for the supporting walls. Those walls, inserted between the tracks, bear on caissons drilled into Manhattan bedrock.

Angled columns do more than press downward: under wind loading, parts of the structure can pull upward. To resist that uplift, post-tensioned anchors tie the building to rock. Because an inaccessible anchor would be extremely difficult to replace from the rail yard, its tendons travel through U-shaped ducts whose two ends return to ground level. The system can be tensioned, and, if necessary, serviced, from above.

Designing around motion

The foundation is shared with two dozen railroad tracks, so structural strength was not the only concern. Passing trains also send vibration through the train shed and into the building.

Engineers used measurements from the former Union Carbide tower to calibrate a digital model of how that vibration moves through the rock, foundations and columns. After more than 150 analytical iterations, the resulting model guided the new structure’s vibration performance. Separate wind-tunnel studies led to a 280-ton tuned mass damper near the top of the tower, where a suspended weight counters uncomfortable movement during strong winds.

The visible fans are consequently not decorative camouflage. They reveal how the building works, spreading outward to receive the tower and narrowing toward the few places where its weight can safely pass between trains.

Zoning shaped the skyline, too

Engineering made the tower physically possible; the 2017 Greater East Midtown rezoning made its scale legally possible.

In December 2018, JPMorganChase transferred 666,766 square feet of unused development rights from landmarked Grand Central Terminal. The transaction generated more than $41 million for East Midtown’s Public Realm Improvement Fund and over $10 million for the terminal’s preservation program.

The project also provides a 10,000-square-foot publicly accessible open space along Madison Avenue, adjoining wider sidewalks and an existing Metro-North entrance. The fan columns help clear the ground plane, giving the completed tower 2.5 times as much outdoor space as its predecessor.

JPMorganChase officially opened the 60-story, 2.5-million-square-foot headquarters in October 2025. It was designed for 10,000 employees and thousands of daily visitors. The all-electric building purchases renewable power from a New York State hydroelectric plant and is intended to produce net-zero operational emissions, claims that concern its ongoing operation, rather than the substantial embodied carbon required to demolish and replace a skyscraper.

The tower’s height dominates the skyline, but its defining achievement lies below eye level: a structural system threaded through one of New York’s busiest pieces of transportation infrastructure without asking the railroad to move aside.

Sources

• Severud Associates: 270 Park Avenue
• STRUCTURE Magazine: 270 Park Avenue, Modern Structure for a Modern Workplace
• New York City Planning Commission: 270 Park Avenue Text Amendment
• JPMorganChase: Grand Opening of 270 Park Avenue
• Foster + Partners: 270 Park Avenue
• Construction Dive: Demolition of the Former Headquarters