To help ensure that residents of the Île-de-France region, including the poorest, are not housed in substandard and/or unsuitable housing, the Île-de-France Regional Health Agency (ARS-IDF) has reinforced its strategy to combat substandard housing, which also involves an outreach approach to communities by visiting them to improve their living conditions as part of a comprehensive health-focused initiative. This policy mobilizes 50 full-time equivalent (FTE) staff members, a significant investment identified as a key priority by the ARS, one of whose major objectives is to improve the socio-environmental determinants of public health. This initiative is part of a much broader policy implemented by the ARS to combat substandard housing. Furthermore, promoting health in relation to housing requires going beyond mere intervention in substandard housing.