Embassy designs become more diplomatic

The proposed new home for the US embassy in London is part of a trend away from the fortress look.

The new US embassy in London, designed by the Philadelphia architects KieranTimberlake, will be a "beacon of democracy".

If the plans for the new US embassy in London are anything to go by, an era of transparent, if not exactly approachable, diplomacy beckons. The glass cube, which is raised from the ground on stilts, has been designed by the Philadelphia-based architecture firm KieranTimberlake. It will be surrounded by a 30m circular "park", or stand-off zone, complete with its own moat. Building will start in 2013, with completion expected in 2017, at a new site overlooking the Thames river, not far from the MI6 building, and about a mile from the Houses of Parliament.

The design was chosen by a panel that included the former ambassador Clyde Taylor as well as the British architect Lord Rogers and the property developer and art collector Lord Palumbo. "We hope the message everyone will see is that it is open and welcoming," said James Timberlake, the leading architect on the project at its unveiling in London on February 23. "It is a beacon of democracy - light-filled and light-emitting."

The 12-storey cube will be clad in blast-proof glass. Layers of plastic vertical fins, which will be attached to the facade like boat sails, will help to soften its hard, office block-like edges, while converting sunlight into electricity and acting as a sunshield for the interior offices. The proposed structure's green credentials are, of course, impeccable. The embassy will be carbon-neutral as well as almost self-sufficient in energy and capable of operating off-grid "for an extended period", said officials.

KieranTimberlake, relatively little known outside the US but responsible for college campus buildings at Cornell and Yale universities, was the surprise pick from a selection of internationally renowned architects, including Richard Meier & Partners, Thom Mayne's Morphosis and Pei Cobb Freed & Partners - all of whose principal architects have won the Pritzker Prize. IM Pei recently designed the Museum of Islamic Art in Doha and was also behind the Louvre pyramid in Paris, while Richard Meier built the Getty Centre in Los Angeles.

It was a tough challenge: how to symbolise American modernism in a world post-September 11, 2001. Embassies, particularly American ones, have become known for their dreary, fortresslike appearance. The current structure, designed by the American architect Eero Saarinen in 1960, and located in London's Grosvenor Square in Mayfair, marked the start of the trend. More recent models include the imposing US embassy on the banks of the Tigris river in Baghdad, which opened a year ago, and is now the largest in the world, housing 1,200 staff, and that in Islamabad, which is still under construction.

Unalluring embassies in conflict zones are understandable, but what about the US outpost in Berlin? Opened in July 2008, one architectural critic described it at the time as having "a trace of Alcatraz." Timberlake's plan, in contrast, is rather sunny. Sunny, though, doesn't come cheap. With its reported budget of $1 billion (Dh3.7bn), it will be the most expensive embassy in the world (Baghdad cost around $700m and Islamabad looks set to cost about $850m).

Despite the impregnable appearance of the present London building, one of the principal reasons for relocating south of the river is that in such an overcrowded residential and commercial area (Grosvenor Square is only yards from Oxford Street) appropriate security measures can no longer be provided for its 1,000 or so staff. Battersea will also give it the space it needs for appropriate self-protection without annoying the neighbours - something that became a regular gripe with Grosvenor Square residents after unsightly blast barriers were erected in 2001.

The building has now been sold to a Qatari developer, who reportedly has plans to use the Grade II-listed structure (a special status conferred by the English Heritage organisation to protect the fabric of historically significant buildings) as luxury apartments and a hotel.