This paper is based on the idea that analyzing sustainable development (SD) regarding legitimacy is possible provided we consider a particular vision of sustainability that gets around problems of common humanity and of common dignity. As we consider the Nord – Pas de Calais Region’s public organisations we can see the implementation of SD raises a double questioning. First on a new civic reality proof that competes or completes the elective proof by the establishment of participative procedures. Then on the industry ground at work in transversal organisations. These two elements are constituent of a new mode of coordination based on SD projects or LA21 projects.