Philadelphia-based practice Kieran Timberlake has won the competition to design Britain’s new US Embassy.
The £500 million complex will be built at Nine Elms south of the river Thames in Battersea following a move from the existing base in Grosvenor Square.
The embassy will be built close to Terry Farrell’s high-security MI6 building and is expected to start on site in 2013 for occupation in 2017.
Kieran Timberlake beat off competition from Morphosis, Pei Cobb Freed & Partners and Richard Meir & Partners.
An initial shortlist of nine was drawn up by the US State Department with all the firms picked US practices.
This was explained as the result of “security” concerns and because only US architects had “experience in the design of American embassies and other buildings”.
British architects may be allowed to take on sub-contractor roles.
Those sitting on the design jury included Richard Rogers and Peter Palumbo.
Last year Rogers said the new building would likely be “a fortress” and added: “You need to have some defence ground around [the building].”
Initial designs for the building have already attracted criticism from Cabe and English Heritage with other objectors including the Port of London Authority, London mayor Boris Johnson and local residents.