¹Welsh School of Architecture, Cardiff University, Cardiff, UK

Copenhagen is internationally and rightly recognised for people-centred city spaces and a healthily expanding public realm. It is fine to admire the place, but this well laid out book sets out to explain some of the work that has led to the current status.

Jan Gehl's first book, the classic Life Between Buildings, established the importance of proximity and quality of the public realm. Gehl demonstrated that easy to access places are more heavily used, especially if the space is well proportioned, with fine materials and a range of integrated options. The principles, based on observation of people, rather than a theoretical notion, support active, social cities where citizens thrive on contact and interaction. As the director of the Center for Public Space Research in the School of Architecture at the Royal Danish Academy of Fine Arts, Gehl, working with Lars Gemzøe, continued the research which led to two books, Public Spaces, Public Life and New City Spaces which together offer a descriptive view into the growing public realm in Copenhagen and internationally. New City Life adds a necessary third by proposing a set of factors by which a space can be measured.

As cities have developed over the past 120 years, the activities that occur in streets and squares have developed from necessary activities to more optional activities. Where once people lived and worked in the same street that provided space for passage, sewage, storage, animals, and toil, city uses are more segregated and personal functions removed from public view. The authors draw a convincing story of the street, formerly a place of business, commerce and even personal needs, grown to a destination for recreation and leisure activities, year round, and by diverse groups of users. In between, Copenhagen managed to displace the 'car invasion' of the 1960s and 1970s. As necessary activities declined, the opportunity for passive and active activities flourished through active intervention of the city. The first pedestrianised street in 1962 was met with concern for lost business and protests that Copenhagen was not Mediterranean! Yet the success of Copenhagen is about more than the initial chutzpah to remove cars; what is remarkable is the commitment to the wide-ranging supporting changes that allowed the city to thrive without cars: improved public transport, improved cycle networks, improved conditions for pedestrians, improved housing, improved material quality, all handled gradually and with careful observation of each step. In the age of slow food, the authors seem to argue for a slow approach urbanity. Each adaptation allows users to modify their habits and find new ways to use the city. No longer merely required to be in the city due to commerce or proximity, the studies show that city dwellers and visitors use the city for enjoyment and leisure, year round despite the northern clime.

Therein lies an interesting aspect: who uses the city and how does the city support diversity of uses? The authors refer to a city report, Advice Analysis that identified five groups who have different interests and needs of the city. In doing so, the report attempted to evaluate how these groups used the city. Here New City Life offers itself as a sort of manual for other cities. How transferable is Copenhagen's success? When New City Life illustrates a 24-h city for all cultures and ages, I am left wondering if the recipe is so simple. The drinking culture in the UK ensures 24-h city districts but these are rarely places that families venture, much less those out for an engaging evening of culture demonstrated by the authors. Denmark's history of socially democratic awareness perhaps allows an extra advantage.

Certainly successful places inspire use, and populated places inspire a sense of security and engagement in society. Despite many protestations of a population isolated by mobile phones, internet and personal entertainment devices, the authors argue that creating a diverse, healthy and vibrant city is possible. Empirical data from 40 years of study are presented that measures the increased population in the spaces of the city throughout the day and year. That this relates to an increase in the quality of spaces is advanced with observational studies of more varied leisure and culture events and more people using the city for pleasure rather than necessity.

The argument is supported by a set of 12 'Key Quality Criteria' assembled into three supporting categories: Protection – safety, security against traffic, crime and sensory infractions; Comfort – opportunities to walk, stop, sit, see, hear and play; and Enjoyment – issues of scale, positive climate and sensory experiences. As a table, the criteria work as both a hierarchy of base needs in public space (protection) to quality goals (enjoyment) and a rating system. This rating system is applied to a range of space types – movement spaces, transport hubs, waterfront space, secluded space – both within the city centre and in the outlying city. Spaces that score high are active, multifaceted places while over-scaled or diffuse spaces are empty and intimidating. Here are locations of necessary activities (pedestrian-commuters who use a particular route), optional activities (people watching on the benches and ledges of the city) and recreational activities (sport, culture).

This is hands-on thinking: no new theories are proposed, no new urbanism offered. As the phrase 'sustainable urban design' appears increasingly without definition, practical instruction such as this is vital, and invigorating. This is design about people (life), not form or ideas or image. Embracing the importance of good design, this book is a manual for other cities that strive to emulate Danish success.

As with the previous books by Gehl and his collaborators, this is beautifully illustrated with finely observed photographs. Simply written, the difficulty of urban design is disguised. It would be helpful to know more about the economic and political aspects that allow and encouraged this development; the brave city officials who decreased the parking and increased public transport would help to flesh out a text that is at times a bit merely expository.

It is sad to note that the Center has been effectively disbanded (see Wrong Way Go Back, by Rob Adams), as it was known under Gehl. Who will carry on these studies objectively, providing the numbers and evaluations needed to support the maintenance and growth of the public realm? The Center never enjoyed a position of respect by the Academy despite its influence not only in Copenhagen but also as advisor to cities worldwide (Melbourne, Bogotá, Amman to name a few). The development in the next 40 years will be a test of the sustainability of the Copenhagen model, and we will be poorer if there is no chronicler and champion with the experience and insight of Gehl and Gemzøe.