From its foundations laid more than one hundred years ago, to the cooperation between government intervention and private initiative to put into place what was not yet known as a public interest service, the HLM Movement has inherited a range of organizations, strongly anchored in their territories, belonging to different families and having the mission of housing those who struggle to do so through the housing market. It has largely developed its activity of production, in rental housing and social ascension over the last fifty years and its social housing assets are therefore relatively recent. It has thus been a major player in the improvement in the housing conditions of households. Today, it carries out its activities in a world that has deeply changed, but where the existence of economic and social regulators that the HLM organizations constitute remains indispensable: the current crisis can only confirm this. In a few decades, the demographic and social composition of the population housed has encountered major changes: the family type of young employees with average incomes with children has partly given up its place to more modest households, amongst which a growing share of a single person and elderly households. With the implementation of the opposable right to housing, social housing capacities are subjected even more to the requirement of housing the most underprivileged persons and families. These requirements should nevertheless not put into question the imperative of social mixing that seeks to keep social housing’s mission as broad as possible and refuses concentrations of social cases in the same neighborhoods, which would put into question the integration of their inhabitants in society. No definition of social housing exists which is unanimously accepted.

Several approaches are indeed possible: -depending on State assistance; but the multiplicity of the forms of assistance makes this approach complex with regard to flows, even more so in terms of capacities;-as housing is accessible to low-income households, because it is made available at a price set at a level below the market price, or because its access is reserved for households whose income is below a cap; even if care is taken to introduce the notion of decency or minimum quality in order to eliminate shanties, such a definition is readily overturned by the existence of assistance to individuals to which every household is eligible under the sole condition of resources;-in terms of landlord organizations for social housing; this is without a doubt the most frequent definition and social housing is often assimilated to the HLM housing capacities. However, social housing is not necessarily only rental property and social rental housing is not limited to HLM’s.