The 2008 economic crisis has opened the door to new strategies for managing urban resources. In fact, the interest in urban commons (UC) has (re)surfaced both within and outside academia. While literature accounting for existing experiences is growing; UC as a practice begs for further systematization concerning the needed negotiation between institutional recognition and informal self-organization. This is particularly true for temporary urbanism, a strategy for the social repurposing of temporarily unused buildings, whose precarious nature has been deemed to represent just a fixing to the neoliberal logic. In this regard, a non-institutional perspective can help shed light on citymaking as a composite practice in which both institutional and non-institutional actors not only coexist but presuppose each other. In this paper, we explore this issue by focusing on two non-profit organizations working in the Rotterdam and Brussels's housing market: Stad in de Maak and Communa. Through in-depth interviews with the founders and core members of these organizations, as well as with participants to their projects, we show how SidM and Communa operate as intermediaries in the housing sector, filling the gaps left by the market and public actors. Most importantly, our research questions the extent to which the enacting of commoning practices by these organizations can become a pillar of citymaking, configuring an iterative disclosure and (collective) reclosure of urban resources. Evidence shows that, while enacting temporary urbanism differently, both organizations strive for social cooperative ownership of spaces for consolidating their presence in the cities.@en