In recent years, many cities have adopted action plans to become climate neutral in the coming decades. Hereby, a strong motivational factor has been the goal to realize a win-win situation in the long term: climate neutrality and sustainable functioning are not only beneficial for the environment, but are equally beneficial for society and for the economy if well-integrated trajectories are adopted. Nevertheless, as actors across the fields start to implement these plans, many practical obstacles have arisen. These barriers are typical of a systemic transition: dominant practices are characterized by path dependencies, vast institutional frameworks and vested interests that are hard to break through. At the same time, relevant initiatives typically show some elements of uncertainty and a long term return, factors that make it difficult to attract financial investments. The present article addresses the state of the art for current transition experiments in the region of Flanders, Belgium, focusing on actions related to energy and buildings in cities. A brief overview of the state of affairs in several cities and provinces is presented, and some important opportunities and bottlenecks are identified. The resultant findings are tested against the framework of transition theory and related literature on the subject. Subsequently, a set of possible strategies to overcome the above mentioned barriers is formulated. These strategies focus on effectively mobilizing actors and investments.