In order to achieve decarbonization in cities, it is crucial to spatially limit the first phase of intervention: starting with neighborhoods is fundamental for planning, social, governance, and practical reasons. Pilot projects involving neighborhoods, whether newly built or existing, allow for initiatives with public and private actors on a smaller scale, endow policy makers and all stakeholders with an experimental attitude in measuring the benefits of different actions, and permit actors to tackle challenges and overcome obstacles with more ease and with tailored solutions. The scale of the neighborhood is appropriate for testing the readiness of communities to change and for ensuring that the change is real, rooted in the community, and supported by public and private actors. Indeed, for the operation to be truly effective and the decarbonization targets to be reached as quickly as possible, a systemic effort is needed: a commitment by all citizens, associations, workers and professionals, the city, and even higher levels of governance along with tangible actions to make decarbonization simpler and more feasible.