One World Trade Center is the tallest LEED building in the Western Hemisphere

Dive Brief:

The 104-story, 1,776-foot-tall One World Trade Center tower has been awarded LEED Gold certification from the U.S. Green Building Council for achieving significant sustainability measures in engineering and design.
Environmental sensors throughout the building transmit energy consumption and air quality data to a centralized building management system while mechanical systems adapt to room occupancies to achieve maximum efficiency.
Variable Voltage Variable Frequency elevators generate additional building energy from system braking. Aa glass curtainwall surrounding the building minimizes solar heat gain while allowing natural light to reach 90 percent of interior spaces.

Dive Insight:

First up on the spec list for One WTC wasn’t a hard technology but a safety-minded design consideration: Elevators, stairs, communications equipment and ventilation shafts are encased within a concrete core whose walls are more than 2-feet thick. The protected core, along with a blast-proof podium, call to mind the post-9/11 concern over building safety, particularly in densely populated urban centers.

Building materials were also top of mind. More than 400,000 tons of concrete as well as 46,000 tons of steel were used in the building's construction, with recycled glass, gypsum and concrete making up 40 percent of construction materials to help make the LEED Gold mark. Recycled materials are particularly important as the USGBC mandates the long-awaited transition to LEED v4 later this month, which renews its focus on material ingredients and origin and rewards project teams that choose locally and sustainably.

And although One WTC's base is dense, the building features a glass curtainwall from the observation level down to the 20th floor, reducing solar heat gain and glare while substantially limiting electric light dependency throughout the building. Similar to technologies being used to provide supplementary power to electronic vehicle power trains, energy produced from elevator breaking can be juiced back to the grid.