What once was the world’s tallest building, the Empire State Building is undergoing a $500 million eco-friendly makeover that will cut energy consumption nearly 40% in the next three years. The famous New York City landmark is the test case for a new process of analyzing and retrofitting existing structures for environmental sustainability, which will provide a replicable model for similar projects around the world.

The program is being spearheaded by former President Bill Clinton’s Clinton Climate Initiative, as well as the Rocky Mountain Institute, Johnson Controls Inc. and Jones Lang LaSalle.

“In this distressed economic climate, there is a tremendous opportunity for cities and building owners to retrofit existing buildings to save money and save energy,” Mr. Clinton said today.

On the outside, the building will get 6,500 windows refurbished into triple-glazed insulated modules, dramatically improving summer and winter efficiency. On the inside, the 78 year-old building is getting upgraded lighting, lighting controls and lighting design; upgraded or overhauled furnaces, chillers, and air-handlers. There will also be an emphasis put on demand-side management systems, allowing tenants to use their energy efficiently.

“Commercial and residential buildings account for the majority of the total carbon footprint of cities around the world – over 70 percent in New York City,” said Anthony E. Malkin of building owner, Empire State Building Company. “Most new buildings are built with the environment in mind, but the real key to substantial progress is reducing existing building energy consumption and carbon footprint.”

Read more at cleantechnica.com