Utilising urban policies to facilitate transition towards a post-carbon future requires a drastic change of direction in current policies. Yet the uncertainty associated with change can often stifle action. Creating visions of a post-carbon urban future can help generate a positive image of the transformed city in which urban life quality, economic and social vibrancy improve for citizens, while carbon emissions decrease. Creating a roadmap based on such visions and scenarios translates the envisaged and necessary transformations into feasible small-scale actions. Developing a policy programme based on post-carbon visions and roadmaps can transform the ambitious goal of achieving a post-carbon society into manageable and measureable steps of change, without losing sight of the long-term goal. Visions are thus a useful instrument to foster the necessary foresight and consensus to support post-carbon policy changes. The types of policy changes and the sectors to be addressed depend on the specific situation of the city, including the necessity and feasibility of actions.