The UK Prime Minister's residence at No. 10 Downing Street, London, has won a sustainable building award for best year-over-year improvements in sustainability.
The building, which houses 152 workers in addition to the U.K. prime minister's residence, was named the winner of the "in-use special award" by the respected BRE Environmental Assessment Method.
BREEAM said No. 10 was the building that has made the most year-on-year improvement among 800 buildings in the scheme, across the UK. Located in the Whitehall section of London, No. 10 Downing Street is similar to the White House in the United States.
The 300-year-old building earned the accolade for a range of improvements undertaken in the past five years, including new boilers, low-energy lighting using motion detection, and using the heat from IT equipment to heat water. There is even a water tank buried underneath the garden for times of drought, where rainwater collected from the building is stored.
Other eco touches include low-use water fittings, better insulation, over 90 percent of construction waste being recycled, and a real-time display on the No 10 website which shows how much energy the building is using. Under the program, the building's display energy certificate rating has improved from E to D since 2009.
The assessment covered March 2011 to March 2012, which saw electricity usage 13.5 percent lower than the same period the year before.
The renovations are not the first time the historic building has undergone a retrofit. In 1958, an investigation commissioned by Harold Macmillan found dry rot throughout the building's floorboards and doors, prompting a decades-long rebuilding project that is estimated to have cost around £3m.
Howard Parsons, project manager at 10 Downing Street, said: "It was important for Downing Street to have an independent and impartial assessment of the success of the environmental and sustainable initiatives undertaken, and their effectiveness in reducing energy consumption and cost. The assessment has mapped our progress so far and highlighted areas for future focus in our drive for continuous improvement."
The BREEAM "in-use" category recognizes building managers who have reduced "the running costs and improve the environmental performance of existing buildings".
In January, the government launched its flagship green deal loan scheme, designed to encourage homeowners to improve the energy efficiency of their homes, and cut energy bills and carbon emissions.
Read more about Great Green Homes.
[photo via Flickr/robertsharp]