A city is created as the result of population movements which have been more or less well managed and tolerated. To what degree is it possible to talk about poor quality or degraded urban environments? To make a district sustainable is to give it a sort of “brand image”, to avoid any suggestion that the district is to be avoided. The local environment has an important psychological effect on people which implies that this environment should be possessed of meaning. Many factors affect decision making including budgets, the identity and nature of the decision-makers and the type of decision to be implemented (greening...). Safety and security in those urban areas defined as being difficult depends on maintaining or encouraging the return of social variety. This variety should be visible in the community which should include members of all age groups and all socio-professional categories. It is imperative that all the appropriate means should be made available to encourage variety in the community.