This work provides a long-term study of housing development in the Brest region (France). Its main objective is to test the efficiency of the French laws and of urban planning bylaws to control housing development in the coastal zone. Based on the yearly status of available plots, a panel longitudinal analysis (1968-2009) is developed. It combines survival analyses with spatial-temporal diffusion indices, to assess their joint effects on the urban form evolution considering accessibility, proximity, spatial contiguity, temporal continuity, edge waves versus leapfrog growth, etc. That allows testing hypotheses about the diffusion processes, and the achievement of sustainable urbanism to increase density, promote adjacency and avoid urban sprawl and its detrimental effects on the environment and climate. The main finding is that national laws need land planning to deploy locally and that municipalities and stakeholders still prefer economic development over environmental conservation. That is putting emphasis on a restricted (short term) view of sustainable development.