What's Green and 86 Stories Tall?

Photography by Daniel Schwen

One of New York City's most iconic buildings has now become one of its greenest: the 80-year-old Empire State Building has been awarded LEED-Gold for Existing Buildings certification from the U.S. Green Building Council.

But it's also serving as a example for other large and drafty old buildings: the strategies used in the project, which will reduce the building's energy use by 38 percent and save $4.4 million in energy costs annually, have been published as an open-source model so that the results can be replicated in other buildings.

Although the project will reduce greenhouse gases, that wasn't the primary motivation of the building owners. With the help of the Clinton Climate Initiative, they put together an engineering dream team and set out to either prove or disprove the cost-effectiveness of energy retrofits, according to a white paper about the Empire State Building's sustainability program.

The results were definitive: The retrofit will pay back the costs of the project in just three years, making the Empire State Building one of the largest and splashiest examples around of the economic viability of sustainability, even for old buildings.

Information about the project, including the analytical model and specific money-saving projects can be found on the website, esbsustainability.com, created by another of the project partners, the Rocky Mountain Institute.

Wonder what convention center might be up for a similar project?