In her thesis supervised by Prof. Emmanuel Rey et awarded by the PhD School of Architecture (EDAR) 2019, Judith Drouilles, of the Laboratory of Architecture and Sustainable Technologies (LAST), shows that peri-urban residential neighborhoods consisting of single-family homes have a lot of scope for improvement in terms of sustainability. Based on five prospective scénarios, her analysis concluded that a wide range of solutions and awareness-raising initiatives are needed to make these neighborhoods more sustainable, for example through car-pooling and car-sharing, community gardens and shared services. If smaller homes were built for retired people, they would not have the burden of maintaining a plot of land and would be able to maintain their social contacts, while single-family houses would become more densely populated as new families move in. Non-renewable fuel prices are also expected to rise in the future, which could seriously affect people in these areas, who depend on their cars to get around and whose energy systems are outdated and carbon-intensive, particularly when they retire. By making simulations over 35 years, the researcher showed that the slow turnover of single-family houses was hindering progress towards sustainability transitions.