From Mitterand’s Grands Travaux of the 1980s to the present, Paris continues to change; from north to south, from east to west, it is a city in constant movement, an immense and endless construction site. Paris is a city that highlights the strong political will of various presidents, each of whom has left a strong mark on the urban and social evolution of the city. Given the complexity of urban transformations, to make them truly feasible on the one hand France has always created true and proper ad hoc management structures and, on the other hand, constantly analysed its urban planning instruments and regulations in order to bring them closer to the real needs of the city and society. This binomial of management (Management Company and Legislative Instruments) has ensured that in France large urban transformations are realised on schedule and with quality, guaranteeing their economic, social and urban sustainability.