The development of housing policies has returned to be a main topic in the Italian government agenda: in the last ten years, the growth of real estate values turned out to be far more important than the real incomes and led to a new social housing demand. Public supply for ownership and rent at social values, however, was reduced significantly in recent years due to the end of national funding. It follows that local authorities, especially municipalities, have to promote the development of social supply with innovative tools. The aim of the paper is the analysis of the different ways have emerged in recent years for the social housing development through public private partnerships. The paper, in particular, investigates three possible forms of partnership than can be used by municipalities with no need for additional resources in order to promote innovative social housing development. The first one relates to PPP arrangements in urban planning, in which the administration grant development rights and obtains a fraction of the units developed. The second involves the use of public vehicles such as the urban transformation companies, similar to the French sociÈtÈ d'…conomie mixte. The third one requires the use of real estate ethical funds. The conclusions of the paper show that the three models present strengths and weaknesses and require local governments to clear priorities including, in particular, the level of risk to be taken in such operations and willingness to hold property in the long term.