The inventory of urban brownfields in post-industrial European metropolitan areas and the study of regeneration projects highlight the absolute necessity of these resources for the sustainability transitions of urban territories and the undeniable complexity of this type of process. Given the complexity of the variables involved, there is no simple and unambiguous recipe to make urban territories evolve towards more sustainability. In a synthetic way, we recall how this book examines the strategies and methods of regenerating urban brownfields through the lens of sustainability at the neighbourhood scale. Then, we question how the urban brownfield phenomenon will evolve in the decades to come. Finally, we argue that it is through inter-disciplinarity of approaches that neighbourhoods in transition can contribute, on their scale, to the mutation and adaptability of urban territories.