ABSTRACT
London’s bid for the 2012 Summer Games promised they would be the most sustainable ever. A challenging brownfield site was chosen for the Olympic Park: there would be no permanent structures that did not have a legacy use, there would be a target of 90 per cent of all demolition waste to be recycled.
Originally it was thought there would be no need for another 80,000-seat stadium in London, so the original plan was to remove the upper part of the structure after the Games, creating a 25,000-seat legacy athletics stadium.
As the design team of architects Populous and structural engineers BuroHappold began work, the brief changed. The stadium would be retained largely unmodified. The two-tier design consisted of a low-carbon concrete base tier topped by a steel and concrete upper tier. Two-thirds of the seating was covered by a cable-stayed PVC-coated polyester roof. Overall, the 2012 stadium was one of the lightest ever built, vastly reducing its carbon footprint.
After the Games the roof was replaced by the largest single-span cable net roof structure in the world. The running track remained, but retractable seating was installed that could move out over the track. The stadium now hosts both a Premier League football club, field athletics and concerts and frequent Rugby Union matches.
