Revealed: £1bn design for Chelsea Barracks

The billionaire Candy brothers bought the 12.8-acre site with the Qatari government in January, and plan to transform it into a "world-class" housing estate.

Situated between Sloane Square and the Thames, the deal makes it worth £75 million an acre.

It dwarfs the £150million paid for the brothers' other flagship development, One Hyde Park.

The devolvement will see the Sixties barracks turned into what Nick and Christian Candy have described as the 21st century equivalent of the great estates of Mayfair and Belgravia.

The proposals submitted to Westminster council outline a mix of 638 market rate and affordable residential units.

The site will also house a boutique hotel with two restaurants and spa, shops, a community hall and a sports centre complete with a 25-metre pool.

Included in the plans are details of a landscaped, publicly-accessible park and private garden areas which will see 300 trees being planted.

The flats, some costing tens of millions of pounds, will be fitted out with every gadget and security measure.

The properties will be aimed at the world's wealthiest people looking for a London base. A team of the world's leading consultants have been put together to ensure the development meets the highest specification.

The brothers have commissioned architect Lord Rogers to design the buildings that will replace the barracks, while they oversee the interior design and act as development managers of the project.

Internationally acclaimed landscape architects, the Olin Partnership, will create the park and gardens.

Overlooking the grounds of the Christopher Wren-designed Royal Hospital and Ranelagh Grove, Chelsea Barracks is one of the world's most eagerly anticipated developments.

It was put on the market by the Ministry of Defence two and a half years ago.

When fully redeveloped, the site could be worth several billion pounds compared with the £58.3million it was valued by the Government's National Asset Register.

The consortium, named Project Blue (Guernsey Ltd) is led by the Qatari Diar Real Estate Investment Company, a branch of the Qatari government's Qatari Investment Authority.

Chief executive Ghanim Bin Saad Al Saad said: "We believe the redevelopment of the former Chelsea Barracks will offer a fresh aspect to the whole experience of city living."

The brothers, who are behind some of London's most expensive property and valued at £9billion, have also bought buildings at neighbouring Grosvenor Waterside.

It is thought they plan to integrate the two sites with a pedestrian boulevard to create a super "riverside estate" which will boost prices even higher.