Chetwoods Architects' idea for a living bridge with glass spires and space for allotments has won an international ideas competition that marks the 800th anniversary of the original London Bridge.

The competition asked designers to mark the 800th anniversary of the opening of the original inhabited bridge by imagining a new version based on the present structure.

Judges of the competition organised by the Royal Institute of British Architects unanimously chose the Chetwoods design from more than 70 entries, describing it as 'wildly imaginative'. It involves soaring glass spires and includes space for allotments and a farmers' market.

The competition was organised on behalf of The Worshipful Company of Chartered Architects, a livery company of the City of London.