One World Trade Center’s design is filled with twists. The building, standing 104 stories and 1,776 ft, is the tallest building in the Western Hemisphere and the third tallest in the world. To break up the wind at such heights, floor plates were rotated slightly, with floors shrinking 1 ft per story to create a taper.
The 3.5-million-sq-ft office tower required 45,000 tons of structural steel and 200,000 cu yd of concrete to complete.

The project involved approvals from five state and local agencies, 15 separate consultants and more than 50 primary trade contractors. To keep concrete and steel contractors operational and the project on schedule, Tishman handled the daily management of the trades using building information modeling (BIM) software. This saved the project roughly $100 million and reduced the original construction timetable by six months, says Tishman.

One World Trade Center’s spire is 408 ft tall and weighs 758 tons. Due to its large size, it was barged into New York Harbor in 17 separate sections before crews erected it.

The tower was built with sustainable materials; renewable energy sources; low-energy heating, ventilating and air-conditioning solutions; and high-performance facades. The curtain wall, comprising 12,000 5-ft by 13-ft panels, is ultra-clear, allowing daylight to reach more than 90% of the building and reducing its artificial lighting needs. SOM selected a high-performance, low-E glass coating to minimize unnecessary heat gain, conserving energy to cool the building. The office tower used structural steel produced from 95% recycled materials, and the building features concrete made using fly ash collected from coal plants. Over 87% of construction waste was diverted from landfills, says Tishman. The project achieved a LEED Gold rating.

Conde Nast, One Word Trade Center’s first tenant, moved into the building last November.

One World Trade Center 
New York City

Key Players

Owner/Developer Port Authority of New York and New Jersey

Lead Design Firm Skidmore, Owings & Merrill 

General Contractor/Construction Manager Tishman Construction, an AECOM Company

Structural Engineer WSP

MEP Engineer Jaros Baum & Bolles