What are climate change, urbanisation and ecology doing to the theory and practice of urban design? How does Ecological Urbanism figure in this change? What is Ecological Urbanism? In answer, this book is neither definitive – impossible when a subject is still in motion – nor encyclopaedic – equally impossible when so much has been written on almost every aspect of these essays. Instead, it seeks to rebalance the ecological narrative and its embryonic modes of practice with the narratives of urbanism and its older, deeply embedded modes of practice. It examines the implications for cities and the designers of cities now we are required to again address their metabolic as well as social and formal dimensions, and it explores the extent to which environmental engineering and natural systems design can and should become drivers for the remaking of cities in the twenty-first century. The book is the last in a series of three that I have written that place the environmental at the centre of their discussion. The first, Taking Shape (2001), examined the relationship between nature and culture as it was evolving in architectural theory and practice. The second, Digitalia (2008), examined the extraordinary effect the digital is having on both the conception and practice of design – both avant-garde architectural design and avant-garde environmental design. This one looks at the urban rather than the architectural scale, and a future in which the metabolic and the cultural must be equally understood and valued. For simplicity’s sake the term ‘architect’ is used throughout, but includes ‘urban designer’, which betrays the Anglo Saxon origins of this book, but spares it some clumsiness. With each succeeding book, the discussion has become less and less theoretical, and perhaps more and more exasperated, as the volatility of both climate and urbanisation increase rapidly, and our responses to