World Trade Center leaseholder Silverstein Properties announced last week that its new 7 WTC tower had been certified by the U.S. Green Building Council according to Leadership in Energy and Environmental Design (LEED) guidelines. New York City's first “green” office building, the 750-ft 7 WTC combines a robust, cast-in-place core with a composite steel and concrete floor and perimeter structural system. The use of mixes bearing fly ash, silica fume and slag cement in the foundation and core helped contribute to points earned under the LEED guidelines that recognize a project's use of recycled materials.

New York City suppliers on the project have included Ferrara Bros. and Quadrozzi Concrete. 7 WTC's construction has proceeded without apparent disruption from civic and private interests who continue debating a master plan for the adjacent 16-acre World Trade Center site. The original 7 WTC failed late in the afternoon of September 11, 2001, as fires — ignited by debris from the collapse of the Twin Towers, (1 & 2 WTC) earlier in the day — raged.