The US Treasury Building has become the oldest building in the world to pick up a LEED Gold certificate following extensive work to make it more energy efficient.

The nineteenth century building, the third oldest federal building in Washington, D.C., has reduced its operating costs by $3.5m as a result of a range of retrofit improvements being made.
The Treasury was awarded the LEED Gold certification after: increasing its use of natural daylight to reduce energy consumption; developing advanced control and management of the heating ventilation and air conditioning systems; conducting waste stream audits to cut waste; and increasing occupant space utilization.
The measures led to a 43% decrease in the use of drinkable water, a seven percent reduction in electricity use and a 53% decrease in the use of steam.
The Treasury Building, which stands next door to the White House, is more than two city blocks long and was constructed over a period of 33 years, between 1836 and 1869.
The improvements have been put down to President Barack Obama’s federal leadership order in late 2009, which called on government agencies to lead the way on sustainability.
Since then, agencies, government departments and facilities have increased their efforts to save energy and money. The federal government oversees around half a million buildings, spending $7bn a year in energy costs.
“The Treasury Building – the oldest building in the world to earn LEED Gold – is a shining example of how green building is conserving energy, protecting the environment, and saving taxpayers money,” said Jason Hartke from the US Green Building Council.
Today, there are now more than 800 LEED-certified federal government projects, representing almost 100 million square feet of space.