The book’s conclusion suggests insights from the book and discusses their relevance to help bolster urban spaces of possibilities. Many cultural actors engaged in sustainable urban development remain in small niches and try to influence the texture of the whole city in a bottom-up manner. Solidarity based on trust in networked spaces may lead to new sets of rules, as a form of prefigurative politics. The conclusion discusses how to support the networking between niche actors and powerful actors, toward a more transversal policy allowing the wider development and implementation of visions and innovations coming from urban spaces of possibilities.