This special issue on housing presents a non-exhaustive overview of the scientific literature on substandard housing. In addition, several experimental, innovative, or long-term programs are highlighted: what they have in common is that they address substandard, inadequate, or even the lack of housing. Among the programs featured, the National Fund for Support in Accessing and Maintaining Housing assists households in need. The Abbé-Pierre Foundation—through its SOS Taudis program—supports housing renovations so that occupants can keep their homes and avoid eviction. In Seine-Saint-Denis, a coalition of organizations supports people in all areas, including housing. Regional health agencies and local authorities are key players in the fight against substandard housing: the Île-de-France Regional Health Agency (ARS IDF) is implementing a strategy that actively reaches out to communities. In Lyon, the urban sanitation department combats substandard housing, as does the same department in Besançon, one of the few cities in France to have introduced a rental permit to combat substandard housing. In mainland France and the overseas departments (DOM), the “Un chez soi d’abord” program provides comprehensive support and permanent housing for the homeless, with a specific program for young people.