Led by an experienced team with a shared history at Les Grands Voisins, this third place—housed in a former maritime carpentry school—serves as a laboratory for initiatives focused on ecological, social, and economic transitions. The Ateliers Jean Moulin project was launched in July 2019 following a call for proposals issued by the Brittany region and won by the A3JM association. The space combines artisanal and artistic activities, training, dining, collective housing and shared living, social enterprises, and cultural programming. Supported by the local government, the project is located in an area facing significant demographic and economic development challenges. It aims to address three major needs: affordable workspaces, housing, and cultural programming.

Plateau Urbain supported the A3JM association for three years, and the Ateliers Jean Moulin project continues today without the cooperative.