Aim: This study aims to develop an integrated affordable housing ecosystem by institutionalizing waqf as a long-term social investment mechanism rather than treating it solely as a charitable or housing-finance instrument. It specifically seeks to identify the institutional conditions required to connect productive waqf with governance, Islamic social finance, digital transformation, sustainable urban development, and multi-stakeholder collaboration. Method: The study adopts a qualitative conceptual research design supported by a systematic literature review and thematic content analysis. Relevant literature on waqf, Islamic social finance, affordable housing, institutional governance, digital technologies, sustainable urban development, and collaborative governance was critically synthesized to identify recurring challenges, relationships, and opportunities for institutional integration. The synthesis was further informed by Maqāṣid al-Sharīʿah, Institutional Theory, Sustainable Urban Development Theory, and Collaborative Governance and Innovation Ecosystem perspectives. Results: The findings identify seven interconnected dimensions shaping the development of waqf-based affordable housing: productive waqf potential, institutional fragmentation, complementary financing, digital governance, sustainable urban development, multi-stakeholder collaboration, and institutional integration. Based on these findings, the study develops the Institutional Waqf Housing Ecosystem (IWHE), comprising six domains: productive waqf foundation, institutional governance, Islamic social-finance integration, digital governance infrastructure, sustainable housing and urban development, and collaborative and community-based governance. The framework positions waqf as a foundational institutional resource within a broader housing ecosystem. Conclusion: The study concludes that the effectiveness of waqf for affordable housing depends not only on the availability of endowed assets but on the institutional architecture through which those assets are governed, financed, digitized, developed, and connected with community needs. The IWHE provides a theoretically grounded framework for integrating these functions and offers a basis for policy development, pilot implementation, and future empirical validation.