The Seven World Trade Centre Building

Client: Hellmark
Capex: $700,000,000 USD
Location: New York, USA
Completion Date: 2006

The Seven World Trade Centre Building is the first building to rise after the September 11 attack. The new 52 storey building replaces the original 47 storey building which fell some six hours after flaming debris from the towers rained down on it. While being somewhat taller than the original, the footprint of the new building is reduced to allow the reopening of Greenwich Street which was closed by the original 1986 structure.
Project Details: The new 1.7 million sqft high rise frame consists of over 15000 sticks of steel weighing more than 13000 tons. The building core was constructed with light weight steel columns that are encased as the concrete core follows the steelwork up the building.
Highlights & Challenges: The steelwork was designed to lead the concrete core by up to eight floors with up to fourteen levels of temporary wall bracing utilized to cater for wind and crane loads. These braces could be removed once the concrete core was brought up and the braces were detailed to be reusable up the building. This “steel first” method allowed steel workers to work safely with no other trades working above them as well as facilitating tight construction schedules. Steel erection topped out in October 2004, one month ahead of schedule.