Southwark Council has granted planning permission for the £165m extension at Tate Modern in London.

The 230ft (70m) high, pyramid-shaped extension was designed by architects Herzog & de Meuron.

The 23,000sq ft (2,136sq m) space will increase the size of the art gallery by 60 per cent in order to accommodate its annual 5 million visitors – double the number the current building was designed to host.

As well as providing more space for contemporary art – including photography, film, video and performance – the development will also feature cafés, restaurants, shops and a patron’s lounge. More than 1,000 new trees will also be planted.

Sir Nicholas Serota, director of Tate, said: “We are delighted that Southwark’s Planning Committee has voted unanimously in support of the scheme. This decision would not have been possible without the involvement and support of local residents, which has been crucial to the development of the design. We look forward to bringing to Southwark a landmark building for the 21st century.”

The London Development Agency is contributing £7m towards the scheme, in the hope that the project will be fast-tracked and ready in time for the 2012 Games.

The project will now enter its delivery phase and a development team will be appointed shortly.

The total costs of the development are comparable to the costs of the original Tate Modern: £165m at today’s prices or £215m at outturn in 2012. Details: www.tate.org.uk

Photograph: night view of the new development of Tate Modern from the South, courtesy of Hayes Davidson