One of the world’s iconic office towers, New York’s Empire State Building, is going seriously green, cutting energy consumption by up to 38 per cent and saving around $US4million in energy bills in a major refurbishment.

Owner of the building, The Empire State Building Company, is spending around $US20million on environmental initiatives as part of a $US500 million upgrade ($700 million).

Once completed, the building is expected to achieve an ENERGY STAR score of 90, placing it in the top 10 percent of efficiency for Class A buildings, a major feat for a pre-war property. In addition, it will pursue LEED Gold building certification, the second highest US rating for building sustainability.

The upgrade program, a joint project of the Clinton Climate Initiative, the Rocky Mountain Institute, Johnson Controls and Jones Lang Lasalle, claims to have developed the first comprehensive approach to model steps for the reduction of energy consumption in older buildings.

The details with be shared to help other buildings around the world become more sustainable.

Anthony E. Malkin of the Empire State Building Company said “the new modelling and program offers a clear path to adoption around the world, leading to significant reductions in greenhouse gas emissions.”

“Along with other steps taken, in recycling waste and construction debris, use of recycled materials, and green cleaning and pest control products, 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,” said Malkin.