The ODPM commissioned study "The value for money of delivering affordable housing through section 106" was carried out by researchers at the University of Cambridge and the University of Sheffield. The aim was to provide evidence on how much affordable housing is being delivered through planning obligations, how it is being funded and how delivering affordable housing in this way contributes to mixed communities. The study confirms the importance of using planning obligations for this purpose and that the system is improving and delivering more affordable housing. The main drawbacks are perceived to be delays in negotiation and costs. Government is seeking to address these issues through clearer policy and good practice on planning obligations. The study also found that delivering affordable housing through planning obligations made a valuable contribution to government aims of mixed communities.