The public policy was limited during a long time at the restructuring of working hours. And today, it takes in consideration the asking for an improvement of comfort, the preoccupation for a durable development and the arrival of a lot of inactive people. City must fit out with all those new temporalities. This adaptation would not come by itself because there is a lot of different expectations from the social groups and the risk to generate new inequalities. The residential question is not out of this risk and the social mix really seek can be come up against the social contrasted temporalities. The temporal break can be added to the social fracture.