Non-sustainable housing is easy to spot. Tower blocks from the 1960s or abandoned terraces in Newcastle or Manchester are glaring examples. Less obvious are the sprawling estates of semi-detached houses with large gardens in vogue in the 1970s. In many ways attractive, they produced the unintended consequences of social isolation and heavy dependence on cars.

Designing and providing sustainable housing is less easy. There is, however, at least some agreement over where to begin. Matt Bell, policy director of the Commission for Architecture and the Built Environment (Cabe) says: “There is a remarkable degree of consensus between policymakers and others about what sustainable communities should be.”