S106 is now an important way of providing additional affordable housing. However, most s106 sites also receive Social Housing Grant. The majority of new affordable housing still comes from non-s106 sites, so this study asks whether s106 is becoming the accepted way forward for a growing proportion of sites and whether this is at the cost of a declining number of non-s016 sites. The study explores the relationship between SHG and S016, looking at the costs and constraints on s106 sites compared with non-s106 sites.