Redoing the city over the city is necessary to adapt our spaces to our needs by transforming the existing while preserving the space on the ground… Who is not infinite. Far from the spirit of the tabula rasa, karawitz rehabilitations are carried out in accordance with their original architecture, from the report building to the concrete giant of the 1980s. The relationship that buildings maintain with their neighborhood is thus valued: Here one does not disfigure, one sublime. The second youth offered to these buildings makes it possible to offer the users, often employees, the maximum comfort. Buildings are up to current thermal standards by favoring passive operation rather than deployment of ancillary technologies and adapting to the real needs of the city by turning to more varied uses and evolving.