Global urban and environmental challenges create tensions and vulnerabilities and the need for rethinking modes of city production. Growing spatial and social inequalities in cities raise a concern that traditional modes of knowing and governing the city are no longer adapted. Our project analyses other modes of city production emerging since a decade in tri or quadripartite cooperation in Europe and Southern countries: broad alliances leading to concrete collaborative urban action between citizens, professionals, the non-profit private sector, local authorities and universities. The research aims at filling the wide gap in comparative understandings of the governance of collaborative practices for a just and sustainable city. Research organizations show greater interest for participatory practices, but new alliances’ potentials and their internal mobilization into collaborative urban actions to drive change in planning practices are underestimated . A multidisciplinary and comparative (North/South) approach is necessary to bring major stakeholders to develop common research on collaborative initiatives for justice and sustainability. FAIRVILLE’s research emphasis is on citizen-based collaborative urban initiatives through a methodology also based on collaborative tools, namely their potential for social and spatial innovation through a co-designed analysis of the full process of alliance creation and knowledge production during implementation. On the one hand, the team will investigate the plural forms of knowledge which emerge through participatory and collaborative tools. Identifying the channels and obstacles to shared knowledge and skills in increasingly horizontal collaborations between researchers, facilitators and organized city dwellers, is an important step in Fairville’s contribution. On the other hand, we will analyse the organizational dimension of collaborative practices and their contribution to democratic governance; and alliances’ ability to counteract social and environmental vulnerabilities, deal with conflicts and define a common agenda of socio-spatial justice and transition-to-sustainability. Thus, the project will inform public policies on the outputs for city planning of inclusionary initiatives in regeneration and upgrading programs, risk mitigation, access to sustainable environments and services. It also aims at enhancing city-dwellers’ recognition and especially the role of the less privileged, migrants and women in research and by research. To do so, it is necessary to bring together different disciplines and all types of actors involved in these alliances, in their diversity and complementarity. The consortium includes four types of stakeholders in urban participatory contexts in the Global North and South who implement horizontal work methods with local residents: (a) SSH specialists involved in international research projects on collaborative urban initiatives (b) supra-local organizations and NGO providing support, expertise and peer-to-peer training to citizen movements (c) regional civil society platforms eager to promote community development and support (d) facilitators and civil society organizations including residents. Citizen science is present all along the research process, by engaging residents of deprived neighborhoods working in collaborative processes with consortium members. Democratization of planning process and change in participatory methods precisely come from alliances of some organizations support and advisory groups with residents and generally women among their active members, added to universities. Integration of all these members including non-professionals will occur through a co-elaboration of knowledge production, co-design of survey and planning co-decisions. Together with critical and analytical research Fairville wishes to unpack power relations and critically assess the outcomes: empowerment, increase in influence and more equitable resource distribution.