Trolling around Youtube today, I found a video posted by Sika about the Empire State Building retrofit of 2010, and was surprised and delighted to hear a friendly voice greet me when I pressed “play”. The video’s host is none other than Alpen founder and suspended coated film architectural glass pioneer, Robert Clarke.
Clarke’s work to initiate, oversee and engineer the re-glazing of all 6,514 windows in the Empire State Building is perhaps his most well-known and celebrated project achievements. Ingeniously, he imagined a way to re-use all of the existing double-pane clear glass and boost R-value from R-2 to R-7 by disassembling, and re-assembling the glass units with a center layer of suspended coated film, making them triple-pane units. His method of building an entire glass facility on the building’s fifth floor enabled the work to be done with minimal disruption to tenants and a low embodied energy cost.
Today, with the 8 other efficiency improvements in place, windows are credited to be achieving return on investment 151% faster than initially modeled expectations – full payback is expected to be achieved within the first 5 years.