Energy use in the world’s most famous skyscraper will be cut by more than a third and its energy bill by millions in a wholesale efficiency makeover, project managers say.

The $20 million (£13.7 million) green retrofit is part of a $500m (£341 million) renovation of the famed building.

Anthony E Malkin, of building owner Empire State Building Company, said: “The model built at the Empire State Building will meaningfully speed the reduction in energy consumption and environmental impact and allow more sustainable operations – while simultaneously enhancing profitability.”

The plans were unveiled at a press conference on the 80th floor of the quarter-mile-high building last Monday attended by former US President Bill Clinton and New York mayor Michael Bloomberg.

The president’s Clinton Climate Initiative is helping fund the project, which is intended as a model for other buildings around the world to follow.

Mr Clinton said: “We have to prove it’s good economics, and we have to prove we know how to do it. Every person on Earth who cares about this knows about the Empire State Building.”

The retrofit project will cut the building’s energy use and greenhouse gas emissions by up to 38% and save $4.4 million (£3 million) a year.

Most of the work should be finished within two years and will reduce carbon dioxide emissions by 105,000 metric tonnes over the next 15 years – equal to the yearly emissions of 17,500 cars.

Plans for the building include fitting the 102-storey building’s 6,500 windows with special insulated glass to cut summer heat load and winter heat loss, insulating radiators and installing more efficient air conditioning, heating systems and lighting.

Building tenants will also be able to use an internet system to check their energy use.

Raymond Quartararo, international director of programme team leaders Jones Lang LaSalle, a financial and professional services firm specializing in real estate, said: “By pursuing these strategies owners can save millions of dollars and enhance asset values while significantly reducing greenhouse gas emissions. That’s a win-win for owners, tenants and the global environment.”

The building’s green projects are all due to be completed by 2013.

Mayor Bloomberg said the project shows “the rest of the city that existing buildings, no matter how tall they are, no matter how old they are, can take steps to reduce their energy consumption.”

David Gibbs

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