Tate Modern sets Olympic expansion

Tate Modern, Britain’s most popular art gallery, plans to build a $400-million extension to its riverside home.

The gallery said Tuesday that the ziggurat-shaped glass building, due to be completed in time for the 2012 London Olympics, would almost double the facility’s exhibition space.

The expansion will be financed through a combination of public and private funding, including $13 million from the London Development Agency. It will be built by Swiss architects Herzog and de Meuron, who created the gallery from a former power station.

Designed to accommodate 1.8 million visitors a year, the gallery now gets more than 4 million, Tate director Nicholas Serota said.

The 230-foot-high structure -- which requires planning approval -- will include 10 new galleries and two performance spaces. It will be built on the site of an electricity substation on the south side of the gallery.