Background There are increasing calls for collective action in European urban areas to confront common challenges such as: global warming; the depletion of fossil fuels and other natural resources; economic recession; population changes; housing and employment crises; and current and potential social divides and geo-political conflicts. The active involvement of citizens is crucial to the establishment of alternative models of production and consumption based on closed local cycles and sustainability. To stimulate this commitment to more ecological lifestyles, we need tools, knowledge and places to test new practices and bottom-up initiatives and to showcase the results and benefits of a resilient transformation of a city. Objectives The R-URBAN project aims to demonstrate that networks of active citizens and associations can create alternative models of production and consumption through accelerated introduction of sustainable collective environmental practices that respond to the needs of modern cities in all of their social, cultural economic and environmental dimensions. It will implement a participative strategy to increase the ecological resilience of the town of Colombes - 83 000 inhabitants - in the north-western suburb of Paris (92). R-Urban proposes the retrofitting of the city following the principles of: recycle, reuse, repair, re-think. It will identify existing micro-local good practices by individuals or associations in sustainable activity. It will also map available or underused spaces in the urban environment. Through the promotion of bottom-up initiatives, the project will seek to immediately connect and activate these potentials. It will identify and encourage local skills and the transfer of these skills as well as experimenting with locally closed cycles for energy, water and waste. It will establish networks to facilitate co-ordinated actions at domestic, neighbourhood, city, and regional scales to close chains of supply and consumption as locally as possible in five fields of activity: residential; economic; agriculture; culture; and mobility. The project particularly hopes to see initiatives around the development of co-operative ecological housing, organic urban agriculture, local cultural production and fossil-fuel-free transport alternatives. The project ultimately expects to deliver social, environmental and economic benefits in sustainable ways that respect local cultures and traditions. It will ensure that all land-use changes are reversible, whilst developing actions that make more positive use of available spaces. Expected results: Demonstration of accelerated collective environmental governance strategies at local and regional level; Engagement of at least 15% of the population of Colombes in new sustainable collective environmental practices; A 40% reduction in the environmental footprint of the created or converted urban facilities; Recycling and reuse of more than 75% of waste from project activities; and A ‘practical’ urban resilience charter and a centre to disseminate good practices of urban resilience at regional and European levels.