The Rebuilding of Ground Zero, Part 149

While the Freedom Tower (1WTC) continues rising towards its ultimate height of 1,776 feet, there has been an ongoing issue about how the first 20 stories of the tower will be clad. Under the original design, prismatic glass would clad the exterior, but tests revealed that the glass would not react properly to explosions - it would cause huge shards, rather than turn into pebbles like other tempered glass.

So, the glass idea was scrapped and a replacement was sought.

The new plan still involves glass, but it's of a different type and configuration.

The new design for the exterior cladding on One World Trade Center features horizontal stainless steel panels behind vertical glass fins going up the 20 stories of the fortress-like base.

“They will reflect light during the day and the night and give the building’s base a distinctive look,” said Port Authority executive director Patrick Foye on Tuesday. “In the evening, the combination of the water and the lights on the memorial pools we think, frankly, will be picked up by the glass on the podium at One World Trade Center and it’s consistent with the overall aesthetic of the site.”

These glass louvers will allow backlighting to give a distinctive effect for the base, and hopefully lighten the base, which is comprised of concrete surrounding the lobby area to minimize the effects of a potential car or truck bomb.

The cost for the new glass is $37.2 million for engineering, fabricating, and installing the glass facade and the installation will occur in 2013 as the tower is being completed. The original design glass installation was to cost $80+ million, but no one has made an accounting for how much money has been spent on the original design.