To provide for ever-growing populations, cities build new neighbourhoods, transform old industrial areas, and renew the existing urban fabric. The focus now is on energy-neutral neighbourhoods, but in order for these to work, residents must be engaged and the tactics embedded within a broader social policy. This book revisits the neighbourhood as the appropriate scale to build our urban futures: it is small enough to be tangible, large enough to make a difference. Introducing the concepts of neighbourhood arrangements and ecologies, it provides a new perspective on the relation between participants, resources, and rules to spark change and realise future sustainable living.