In the cities of the world, urban diffusion has proliferated: the model is the Californian one, characterized by a pattern of single-family houses, with some services, shopping centers and the enlargement of the road network. From the British and European residential carpets, Italy develops diffusion territories for example in Veneto and on the Middle-Adriatic coast. They are situations of con-fusion of the rules of the city and the countryside. But in a metropolitan situation, especially in the conditions of the countries of what was once called “third world”, enlargement becomes unstoppable and the quality of construction falls down: no longer the modest suburban residences of the countryside of Campania or of the Roman suburbs, but the mud, wood and sheet barracks of São Paulo, Mumbai, Nairobi. Addressing the informal city as a didactic theme (especially in a thesis lab) after the diffused city represented a challenge. The publication presents design elaborations that, rather than offering solutions, highlight the issues opened by the comparison between the themes of sprawl and slums.
