The paper debates the results achieved in the Sanità district of Naples within the funded research project Play_ACT by the Department of Architecture, University of Naples Federico II. The research investigates community engagement processes in built heritage design for repurposing. Based on a mixed deductive and inductive approach, this paper frames the built heritage in the following ways: (a) a record of historical development and way of life, a linking capital between community and context; (b) the enabler of community engagement, representative of creative skills and work of humankind; and (c) a driving force for growth. The paper analyses several community-driven repurposing practices experienced within European programs. Supported by the ISO 37104: 2019 and UNI 11151-1: 2005 standards, the paper focuses on the replicability of community engagement in built heritage repurposing processes, outlining the commonalities in terms of strategies, actions, and actors involved in: (1) discovery; (2) negotiation; and (3) sharing. Focusing on the Sanità district of Naples, the research experiences the sustainability of community-led repurposing, observing long-lasting spillover effects on the physical, economic, cultural, and social subsystems. Finally, with the support of a heritage case study, Cristallini 73, future key challenges for a durable and inclusive community engagement are outlined: A activation of collaborative networks; B promotion of inclusive dynamics of long-life learning; and C creation of cultural and creative industries.