Book excerpt: Was Britain's postwar rebuilding the height of mid-century chic or the concrete embodiment of crap towns? John Grindrod decided to find out how blitzed, slum-ridden and crumbling austerity Britain became, in a few short years, a space-age world of concrete, steel and glass. What he finds is a story of dazzling space-age optimism, ingenuity and helipads - so many helipads - tempered by protests, deadly collapses and scandals that shook the government.