Environmental issues in the context of housing reveal a resurgence of the commons in contemporary property law. If the commons are sometimes identified with common things and are in this sense outside the field of the appropriable—which the Anglo-Saxon terminology of ‘commons’ emphasizes by avoiding the term property—they can also refer to property that can be appropriated in a common or collective way, whether this community operates under private or public law. Using selected examples, namely a study of ecological cohousing and green alleyways, this paper reveals a resurgence of the collective and the commons, both in private and public space, thus erasing the traditional opposition between the public and the private. More specifically, we are witnessing a renewal of collective usage rights through the commons as well as a transformation of ownership towards what could be called polyfunctional ownership that has a collective as well as an individual dimension. The fact that private property has largely been thought of through the prism of individualism cannot mask the social function of property and its more collective origins. Moreover, alongside access to ownership, the question of access to housing, through collective rights of use or holding, becomes fundamental.