This chapter examines the relationship between urban form and sustainable development. In particular, it outlines a typology of city forms. The three main archetypal urban forms discussed are: the linear city; the city set out in the form of a grid; and the highly centralized or inward-looking city. The form of each archetypal plan may be modified by the prevailing metaphor: the city as a replica or model of the cosmos; the city as a machine; or finally the city as an organism. The grid layout, for example, has been used to express physically both the cosmic and the machine city metaphors (Lynch, 1981). More rarely, as in Gracehill, it has also been used to express the community needs of the settlement built according to the organic metaphor. The Chinese model city uses a grid to relate the city to a cosmic structure (Boyd, 1962; Wheatley, 1971). In Chinese culture the city is designed as a microcosm of the universe, but complete in itself. In contrast, the grid, when used to give form to the city as a machine, emphasizes the autonomous parts, each having a distinct function. Devices such as size, scale or the imposing axis are used to give emphasis to the dominance of the motor car or the world of business: they are never used in this context to mirror the universe. This difference can be illustrated graphically by the contrast between a Roman encampment or the project for a contemporary city by Le Corbusier with the Mandala, which sets out the Indian ideal pattern for city structure (Figure 7.1; see also Figures 6.25 and 6.32).