The Empire State Building in New York, US, is to undergo an extensive retrofit in a bid to improve the building’s energy efficiency.
A total of $19.9m (£12.8m) will be spent on the landmark scheme.
The makeover is expected to cut the building’s energy use by almost 40% and reduce bills by more than $4m.
The project will cut the building’s carbon footprint by more than 100,000t over the next 15 years, according to telegraph.co.uk.
Four central chillers have been replaced, and new windows and smart air circulation systems will be installed in the building.