Abstract We investigate the effects of the implementation of the Social Interest Special Zones (ZEIS) on the housing quality in the city of Recife, Brazil. Aimed at improving housing quality and ensuring the permanence of low-income families near city services and opportunities, the ZEIS was pioneeringly created in Recife and later implemented in most large Brazilian cities. Despite the relevance and scope of such urban intervention, to date, no evaluation of its effects has been implemented. Our empirical approach combines city hall and census track information and considers a difference-in-difference strategy. Our results indicate positive effects of the implementation of ZEIS on the access to sewage services through the general network, access to piped water, and degree of residential/home ownership, but no effects of the policy were found on the number of bathrooms per household or access to garbage collection services.