Sim Van der Ryn and Stuart Cowan present a vision of how the living world and the human world can be rejoined by taking ecology as the basis for design. Ecological design intelligence -- effective adaptation to and integration with nature's processes -- can be applied at all levels of scale, creating revolutionary forms of buildings, landscapes, cities, and technologies.The authors weave together case studies, personal anecdotes, images, and theory to provide a thorough treatment of the concept of ecological design. In the process, they present and explain a series of design principles that can help build a sustainable world with increased efficiency, fewer toxics, less pollution, and healthier natural systems.