Come out of the smartly restored station in Sheffield, northern England and turn right along a traffic-snarled inner ring road. On one side, the number of cranes tells a story of hectic rebuilding – a new leisure centre, a transformed retail quarter with 100 new shops, hotels and affordable apartments.

On the other is a great, grey, monolith of concrete. This is the Park Hill Estate. When it was built in the late 1950s it was innovative and exciting, fit for a postwar city yet to be stricken by industrial collapse. Designed by Ivor Smith and Jack Lynn, it was a revolution in living as dramatic as anything by Le Corbusier.