Benjamin Franklin House, Christ Church Spitalfields, the National Theatre, the National Trust's Osterley Park, WWT London Wetland Centre, Sir John Soane's Museum and LSO St Lukes all joined at the end of 2007.
UVL chairman Lisa Hatswell said: "These venues alone represent all that is visually stunning and totally unique about London venues. Added to our already impressive range of members, you begin to understand the impact we're having."