This book is about the transition to sustainability. Specifically, it discusses ways in which professionals responsible for the production and operation of the built environment are responding to the pressure to make urban development more sustainable. At the heart of this process lies an ability to transform new knowledge about the impact of changing the built environment into practical action. The expertise required is largely in the hands of professionals and, although there is a market for this service, government is responsible for promoting its use and effective application. The general population, present and future, will feel the impact of its quality. The relationships between the market, government, the professions and the public are crucial and need to be rethought carefully – not least because of the new forms of governance that sustainable development may require.