The paper analyses the potential of several local initiatives in terms of sustainability. By sustainability, it is not question here to understand if one initiative is sustainable per se, but to understand if these whole initiatives might lead to a global changing in behaviors that could favor sustainability. The point defended in this paper is that the multitude of these initiatives is sharing common principles. Although sometimes very different in practice, these initiatives are based on a common ground of values. Taken together, they are representing an important movement of actors following an intention of conventional regime to propose in alternative to the existing one. The aim of the paper is to demonstrate this last assertion. After a first part defining what is intended with conventional regime, in the theoretical field of the economy of conventions, several case studies will be presented and analyzed through this theoretical background. Cases are chosen both in a European context and in the "South" context, in order to better figure their diversity. An analysis of these cases will then be presented, in order to show the similarity of these a priori very different initiatives in terms of conventional principles. This paper, the which ambition is programmatic, aims at demonstrating that a track for sustainability could be found in the extension of this alternative conventional regime, based on principles such as proximity, increasing of capabilities and the use of participatory democracy. The change of scale should then be necessary in terms of principles and values, and not in operational terms, through the creation of big entities trying to reproduce what has been succeeded at a local scale.