Selfridges has appointed architect Sir David Chipperfield to lead the £300 million redesign of the east side of its flagship Oxford Street site in London, the biggest ever investment by a ­department store on a single project.

The expansion will see the current luxury handbag section more than double in size to cover some 50,000 sq ft (4645 sq m) of the ground floor. Sir David designed the award-winning River and Rowing Museum in Henley-on-Thames using green oak cladding, concrete and glass.

Work is due to start on the monster Selfridges redevelopment project next month and is expected to take five years to complete.