Although urban brownfields hold significant inherent potential, especially in limiting urban sprawl, a large number of sites are still awaiting a regeneration project. Moreover, many of these projects only partially or superficially address sustainability principles. Hence, concrete courses of action are required to support the evolution of current practices towards increased sustainability. These courses of action, which rely on specific skills and adapted supports, require a complementary approach. In other words, strategies should be conducted consistently at the territorial, metropolitan, and project levels. In this regard, the present chapter provides a series of courses of action to be implemented at these levels. Our aim here is to foster the sustainable transition of metropolitan areas, and more precisely brownfield sites, into lively neighbourhoods.