The key to sustainable urban development in UK cities? The influence of density on social sustainability

High residential density is an important element of the compact city concept alongside mixed land uses, well-connected urban layouts, and easily accessible public transport networks. However, there is little consensus on how dense 'high-density' residential development should be, nor on what are the impacts of such urban environments on residents. This paper attempts to address this gap in knowledge by exploring the concept of density within the context of sustainability, calling on empirical evidence conducted in the UK by the CityForm research project. This research examined the relationship between elements of urban form (including density) and sustainability. This paper specifically makes reference to the relationship between density and aspects of social sustainability, specifically social equity (i.e. access to services and facilities), environmental equity (i.e. access to and use of green/open space) and sustainability of community (including perceptions of safety, social interaction and community stability). An extensive postal questionnaire survey and series of follow-up in-depth focus groups were conducted in a number of neighbourhoods in five UK cities to examine the hypothesis that high-density neighbourhoods were less likely to support socially sustainable behaviour and attitudes than low-density ones. The paper starts with an introductory account of density in the UK to provide the context of the study. It then defines density and the aspects of social sustainability under scrutiny and discusses the claimed relationships as well as the implications that such claims have for policy and practice. The paper then reports on the empirical research findings which examine the extent to which density has any influence on residents' propensity to engage in socially sustainable activities. The paper concludes by critically reflecting on how the findings fit more broadly into the 'compact city' debate in the 21st century, where urban, and not rural, environments are home to ever-increasing populations around the world. (C) 2012 Published by Elsevier Ltd.