The 52-story building is the first Lower Manhattan office tower to be rebuilt after the Sept. 11 terrorist attacks. The new 750-foot 7 World Trade Center is taller and sleeker than the original; its 47-story predecessor rose to a height of 640 feet. Like the original building, 7 World Trade Center is built on land leased by the Port Authority of New York and New Jersey.

"This is a milestone in the rebirth of Lower Manhattan," said Larry Silverstein, president and CEO of Silverstein Properties. He cited the efforts of more than 1,000 construction workers and held a moment of silence for one who died on the job last month. Silverstein also noted the importance this building holds for the entire city. "We had to move quickly, but do it thoughtfully and intelligently. Three years later, we've reclaimed an important part of the New York City skyline."

Silverstein keynoted the Codes and Regs Conference sponsored by the New York chapter of the Building Owners and Managers Association immediately prior to the topping out. There, he proclaimed 7 WTC the "safest building ever built in America." He backed up the claim by explaining that the design of the building is a direct result of the lessons learned on Sept. 11.

Based on that research, "The conclusion we reached was to build this building with a massive concrete core," he explained. The core "contains 2-foot thicknesses of 2000-pound reinforced concrete." He reported that not only is that well above code, but it is also the densest concrete that can be poured. Simply for emphasis, he added, "Ain't nothin' more dense."

Elevators, stairwells, communication systems and all life-safety systems are contained within the core, he said. "It's a totally different rationale toward life safety," Silverstein concluded. When completed, it is expected to become a prototype for all new high-rise construction, including the Freedom Tower and four other buildings that Silverstein will build on the World Trade Center site.

Last month, Silverstein tapped CB Richard Ellis to be the exclusive leasing agent for the 1.7-million-sf site and already potential tenants have come forward to express interest. Steve Siegel, chairman of global brokerage for CBRE, is handling the assignment with colleague Howard Fiddle. Siegel doesn't anticipate any lease signings before next year.

Tenant floors begin at the 11th floor above grade. The untenanted first 10 floors largely are given over to a series of huge bays housing transformers for a Consolidated Edison substation and the street-level lobby facing Greenwich Street, which leads to elevator banks to the tenant floors. The Con Ed substation supplies electrical service to all of Lower Manhattan and replaces equipment destroyed by the attacks on the World Trade Center.

The new 7 World Trade Center is bound by Greenwich, Vesey, Washington and Barclay streets. Architect David Childs, consulting design partner at Skidmore, Owings & Merrill LLP, designed the sleeker building, which allows for the re-introduction of Greenwich Street through the World Trade Center site and for the creation of a new neighborhood park. Tishman Construction Corp., which built the original 7 World Trade Center for Silverstein, is serving as contractor for this project as well as for the 1,776-foot Freedom Tower.