WTC Tower 1 is currently up to the 49th floor. Photo Credit Joe Woolhead

The future 104-story 1 World Trade Center now stands at 49 stories, and since mid-November, its curtain wall is now adding shimmer to the steel superstructure. The façade wall consists of 13-foot-tall steel-and-glass panels that are bolted onto the tower’s perimeter steel columns. The panels start at the 20th floor, while the lower 19 floors will be clad in special prismatic glass that will eventually enclose the base mechanicals. When 1 WTC is complete in 2013, crews will have placed more than 12,000 flat panels and 700 corner panels on the tower.