Sustainable development and the model of the compact city increasingly influence land planning policies. In this context, an inward development and an urban regeneration are suggested by many official planning documents. The advantages of limiting urban sprawl and promoting inward development are well developed in academic literature as well as in official documents. But some political and sociological questions remain unanswered. Which social categories are more likely to go back to the city? Will this movement of return to the city change its social structure? Will it create new inequalities? Studies, mostly in Anglo-American countries, have shown that the movement of return to the city is in many cases accompanied by a gentrification process. In other words, social categories concerned by this movement are rather middle to high classes. Our purpose is to determine if a movement of return to the city occurs in Switzerland, which social categories are concerned and if a process of gentrification is going on. Case studies will focus on the motivations and the residential trajectories of these new inhabitants and determine to what extent the regeneration policies adopted by local authorities take into account this important social dimension of the process.