The Circles of Sustainability fi gure used throughout this book provides a relatively simple view of the sustainability of a particular city, urban settlement, or region. The circular fi gure is divided into four domains: ecology, economics, politics and culture. Each of these domains is divided in seven subdomains, with the names of each of these subdomains read from top to bottom in the lists under each domain name. Assessment is conducted on a nine-point scale. The scale ranges from ‘critical sustainability’, the fi rst step, to ‘vibrant sustainability’, the ninth step. When the fi gure is presented in colour it is based on a traffi c-light range with critical sustainability marked in red and vibrant sustainability marked in green. The centre step, basic sustainability, is coloured amber – with other steps ranging in between amber and red or amber and green. The grey-scale used here is intended to simulate the colour range.