Mass customization is being adopted in many housing contexts worldwide to provide families with dwellings that suit their individual needs at costs similar to mass-produced items. However, in many social housing contexts, there are barriers that can hinder the adoption of mass customization, despite the benefits it could bring to residents. This is the case in the Brazilian social housing context considering house units for families of the lowest income range. This paper explores the possibilities and limitations of applying mass customization in this context to improve the living conditions in these neighborhoods as they evolve over time. This study analyzes the ecology of the system of provision of social housing for the lowest income range, pre-occupancy, and post-occupancy in the neighborhood’s development over time. This study argues that it would be more feasible and bring more and longer-lasting benefits to the stakeholders involved if mass customization were applied post-occupancy.