Some urban spaces are more dynamic than others. While the city centre, suburban areas and consumption spaces are rapidly changing and re-shaping, other parts of our cities seem to be stuck in time, in a permanent standstill. Such areas include stagnant construction sites, green areas and public squares in old housing estates and many forgotten, marginal public spaces scattered across the city. Conventional planning tools might be too slow, too weak or too broad to revitalise such spaces. We propose a different, interventionist approach. Temporary interventions have the power to change the planning process, involve more people and require less time.