Designing High Density Cities for Social and Environmental Sustainability

With more than half of the world’s population living in urban areas, Ng argues for high density cities for sustainability and also for a re-thinking of high density development. While traditionally, poorer cities have been associated with high densities (with many Asian cities having more than 10,000 people per square kilometre), increasingly, planners in more affluent cities are turning to higher density development for a number of reasons, including reducing transport distances and economic efficiency. However, our current notions of high density “…are mostly based on the past, and unhappy episodes of squatters, high-rise council flats and slums”, and this book questions whether we can continue to use the conventional wisdom in the design of high density cities and homes. This book acknowledges the benefits of high density development, but also focuses on the many challenges of designing these cities from a socio-environmental perspective. Ng has compiled 22 chapters on density in the urban setting, divided into four sections, which explore both the technical and non-technical aspects of planning for high density; the book is thus suitable for academics and practitioners alike.

Part I problematizes the notion of high density as well as its relationship to sustainability. It warns against over-simplification of what we mean by density and stresses the importance of context in planning for high density. The author of Chapter 4, Susan Roaf, states that perhaps the primary focus of planning should be on the equitable and quality city, and “…the optimal densities will follow”(page 38). Part II looks at the climatic changes related to urban living in general and dense living more specifically. Part III focuses on the relationship between climate and density, with chapters on thermal comfort, ventilation, sound, daylight, waste, fire, greenery, energy and the shifting scales of environmental assessment. Finally, Part IV looks at the sustainability nexus of social, environmental and economic considerations of high density cities – with one chapter using Hong Kong as a case study.