The idea of sustainability recalls the logic of practice, where practical effects viewed as desirable are made to happen, rather than the field of scientific knowledge, where concepts are constructed to explain reality. When applied to urban space, the idea of sustainability has generated different representations and perspectives for managing cities, from the administration of risks and uncertainties to the increase of "resilience" -the adaptive capacity- of urban structures. What seems to organize analytically the discourse of "urban sustainability" is its division into two fields: on the one hand privileging a technical representation of cities by combining the notion of urban sustainability with the "modes of management of the flows of energy and materials associated with urban growth"; on the other hand defining the unsustainability of cities by the drop in productivity of urban investments, that is, by the "incapacity of the latter to keep up with the rate of growth of social demands", which consequently places urban space in jeopardy as a political territory