International audienceThe aim of this article is to understand the sociospatial changes in process in the peripheral areas of large metropolises, in the North and in the South, as a result of the emergence of a new and relatively uniform housing supply for the lower middle classes. Partly neglected by the public authorities, the question of the trajectories of these new residential complexes, from their construction to their integration into the city through their settlement, arises at different scales, from the local to the metropolitan scale, and with different focuses, from the most technical to the most social. By regarding to the cases of Mexico City, Delhi and Paris, through statistical databases on the one hand and field observations...