Special feature on affordable housing provision. Government is pushing for more social housing in private developments but house builders' attitudes vary significantly. Explains why some house builders are reluctant to provide affordable housing and highlights other barriers to social housing provision such as the shortage of development land. Argues that local authorities could encourage more affordable housing if planning and housing departments worked together on s106 negotiations. Highlights developers who have delivered high levels of affordable housing such as Wimpey and Countryside Properties and cites a good partnership with councils and housing associations as the key to success. Expands on the benefits of partnership and concludes that clearer government guidance is needed to improve the delivery of affordable housing. Includes research by "Regeneration and Renewal" into the number of affordable house completions by house builders. Graphs and chart.