The emergence of energy communities, in the form of citizens coming together to share in-situ renewable energy production and consumption, must be examined not only from a technical or environmental point of view but also above all from a societal and political stance. If energy can – and must – be rethought as a common good, considering its accessibility and distribution as a resource, energy communities can be regarded as commons. They are, in other words, spaces for “politics in practice”. Energy would then be the basis of a bottom-up governance, through which the community is established and then sets rules for using and sharing energy. Consisting of three elements: a resource, a community and the practice of commoning, commons emerge as spaces of bottom-up politics. According to our hypothesis, energy communities are spaces not only for sharing renewable resources but also for an emerging institution, through collective governance embedded in inhabited spaces. The space-anchored ethnographic approach analyses the narratives and representations of the members of two energy communities in participatory housing while observing the consumption and practices of space occupation, as well as material and spatial layout. Through their capacity to reformulate collective action, energy communities become spaces for constructing political legitimacy, i.e., the circulation of knowledge, production of discourse and action on society.