(The lease deal was not the only news coming from Silverstein and Ground Zero. Read more.)

New York Academy of Sciences president Ellis Rubinstein tells GlobeSt.com that the firm looked at as many as 30 potential sites before choosing 7 WTC. "We got an excellent deal," he said, adding that it is approximately $3 million less than what they would have paid at the next choice, 1 Madison Ave. The space will also include a conferencing center in the space that will host major international conferences.

Rubinstein said the academy had no qualms about the security of the site. "The building is spectacular and over code. I think the city will keep it extremely safe."

Over the summer, a $3.80-per-sf incentive for the first 750,000 sf leased at 7 World Trade was put in place as part of a plan to lure tenants to the WTC area. Developer Larry Silverstein have to match the incentives. "These incentives make all the difference in the world," said Silverstein during a press conference. "There will be more (leases) to follow." The 52-story office is bound by Greenwich, Vesey, Washington and Barclay streets. Tishman Construction Corp., which built the original 7 World Trade Center for Silverstein, is contractor for the project. Earlier this year, the New York City Industrial Development Agency approved $475 million of New York Liberty Bonds to be used for the reconstruction and permanent financing of 7 WTC, which is being constructed on a 58,000-sf site. 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 Con Edison substation.