Cities across the world are increasingly confronted with the consequences of climate change, requiring the urgent identification and implementation of climate mitigation and adaptation strategies. As these policies and interventions impact current social, spatial, and environmental configurations, the decision-making process is inherently characterised by conflicts of values and interests. This adds to the unequal distribution of burdens and risks that already concern the most vulnerable and excluded groups, raising questions about how planning processes dealing with environmental and climate issues can ensure equity and legitimacy. Drawing from post-political theory and agonistic planning perspectives, the paper is grounded in the assumption that procedural justice and democratic confrontation are essential to addressing the structural causes and uneven impacts of climate change. Using Bologna, Italy, as a case study, it explores the intersections between community-based climate adaptation and institution-led participatory processes to challenge the post-political condition of climate governance. The paper investigates the role of a specific category of urban commons, namely the Neighborhood Houses (Case di Quartiere), as potential arenas for re-politicising climate discourse. It explores how their widespread spatial distribution across the city and their embeddedness within complex governance configurations can promote the articulation of citizen-led demands, particularly those related to climate justice. Drawing on four years of research involving data collection, participant observation, and the co-design of a participatory initiative in Bologna, the paper offers a critical analysis of the opportunities and limitations that decentralised institutions face in fostering stronger linkages between community-based organisations and municipal authorities, ultimately contributing to a more just and democratic approach to climate policy.