Hong Kong defies the usual correlation of high density with crime, poverty, pollution and disease. It is in the same league as Mumbai and Dhaka in terms of population density and exceeds New York City in its building density. Yet it is ranked in the top group of the United Nation's Human Development Index that includes life expectancy, literacy, education and standards of living. In its total use of energy, it is among the most efficient in the world. Why that is important for the world, how it evolved and the planning and design ideas that support the high density are the major themes of this book. The authors use Hong Kong to advocate higher urban densities as a way of dealing with ‘an impending environmental crisis that embraces such massive issues as global warming, climate change and rising sea levels’. Their book seeks ‘to discover how the place and its components work and extract the underpinning urban design principles, for these can be adapted to guide and inform development elsewhere’ (p. 7). The book is organized around two approaches: one concentrates on ‘“the making” of physical places as historical process’, the other on ‘design ideas that have shaped Hong Kong and with the contemporary generation of ideas that might shape its future . . . it is both historical and speculative’ (p. 21).

The introduction starts with a description of Hong Kong's status today as a world city, a short political history of the factors leading up to its present dense situation with particular emphasis on governmental control of land and the dominant role of public transportation. Then there are several essays touching on the major themes and the role of Hong Kong. Two of them deal with the literature on density, the first on the seminal paper by Robert C. Schmitt, and the other reviewing the inter-related topics of Complexity, Density and Intensity. In between is an argument for compact cities. Chapter 2 cites precedents for dense settlements in Chinese, Hong Kong and Southeast Asian history – walled houses and towns, Hakka villages, Kowloon Walled City, Chungking Mansion and the shop-house. The heart of the book lies in the next four chapters. These link the political and economic context for population growth that made increasing density a necessity. Each one describes a major era: long, low and intense – pre-war development with intense urban development; massing and rising – post-war explosive growth and building of crowded blocks and public housing to accommodate refugees from China; vertical and volumetric – tall buildings responding to increased affluence and higher standards of light and air and amenities; podium and tower – the continued reach to taller buildings and multi-storey shopping malls. In these chapters, the authors show how the building types, street layouts, topography, land reclamation and transportation evolved together. They cite the central role of government: its need to raise revenue through land sales; creating new land through reclamation; the creation of public housing for over 30 per cent of the population; building regulations to improve light and air. Historical photographs, plans and diagrams are used effectively to illustrate the three-dimensional aspects of building regulations and market responses. The last three sections have many interesting and insightful observations and case-studies revolving around the idea of three-dimensionality: re-thinking ground; movement in space and volumetrics. Some of the ideas are nascent in the podium and tower section, discussed in slightly different form in emerging volumetric components and again in the conclusion. It is difficult to detect a framework to order the pieces into a coherent set of ideas.

The book succeeds in its goals to explicate ‘“the making” of physical places as historical process’ and ‘to discover how the place and its components work’. By joining the evolution of design ideas with its historical context, the authors have given planners and designers an important perspective on how the constantly changing context affects the physical forms of the city. On the goal of extracting design principles so that they ‘can be adapted to guide and inform development elsewhere’, there is a necessary caveat. Design ideas were not the initiator of the hyper-density of Hong Kong. The density was the resultant of the complex interplay of particular political, economic and social forces: severe restriction of its boundaries, the pressure of the neighbouring Communist revolution; scarcity of land due to the extreme topography and the influx of refugees. The situation forced the colonial and, after 1997, the Special Administrative Regional governments to use their control of land to promote commercial and industrial developments, private building and public housing at high densities. The planners, builders and designers responded with innovative solutions that enabled hyper-dense concentrated settlements served by public transportation. Today, Hong Kong is a highly energy-efficient city by comparison with other developed cities. But that model with its extreme densities and high-income economy will be feasible only when similar combinations of historic forces and geography coalesce. Otherwise, Hong Kong is an exceptional case-study but not a widely replicable model.