It is now widely acknowledged that there is a pressing need to increase the supply of housing in England, including for those on the lowest incomes. Planning obligations are a major way in which the planning system contributes to the supply of affrdable housing, yet numbers delivered are still insuffient to meet overall needs, vary greatly between different parts of the country and have been affcted by the economic downturn and changes to the planning system. Given these challenges, this research explores what works and what doesn’t in the operation of planning obligations and whether there are alternative localised ways of increasing the supply of affordable housing.