This paper reports findings from recent research examining the relationship between urban design and layout and aspects of social and communal life in urban neighbourhoods. To address this, six UK neighbourhoods of varying densities and layouts were selected for detailed investigation. Data on social interactions, social activities and social networks along with perceptions of the built and social environment of the neighbourhoods were collected through observations, questionnaire surveys and secondary data sources. Neighbourhood design and layout were analysed using spatial network and visibility graph analysis methods. Correlation and multiple regression tests were conducted to test the claimed associations. Findings indicate differences between socializing patterns and structure of social networks in high- and low-density areas. Low-density areas were associated with widely spread social networks and activities with very few strong relationships. In high-density neighbourhoods, respondents had small networks but stronger ties were found. Detailed investigation shows that much of this can be attributed to, among other physical factors: the location of public spaces, visibility from and to these spaces, visual links between neighbourhoods', typology and physical form of development rather than density alone. This indicates that some of the negative social impacts found within high-density urban development might be rectified with better design of neighbourhoods. It is clear that to deliver sustainable development, the compact city will have to be designed with specific spatial and built environment characteristics.