This study investigates the challenges of housing sustainability in Ireland's social housing sector, with a specific focus on Indoor Environmental Quality (IEQ) and maintenance policies. Drawing on qualitative interviews with key stakeholders, including Approved Housing Bodies (AHBs), Local Authorities (LAs), government representatives, private entities, advocacy groups, and social housing tenants, the research identifies critical barriers to achieving sustainability in social housing. Using the analytical lenses of the Multiple Streams Framework (MSF) and Sustainability Theory, the analysis demonstrates that IEQ remains a low policy priority despite growing health concerns, with both policy and economic barriers impeding progress. The findings argue for a substantial shift towards evidence-based housing policies that integrate sustainability and health considerations into social housing maintenance strategies. Findings indicate that the prioritisation of housing supply over other systemic needs, such as indoor environmental quality, has institutionalised health risks, requiring a transition from reactive maintenance to proactive, technology-integrated policies that align tenant well-being with sustainability goals. The application of MSF and Sustainability Theory in the Irish context shows that addressing the intersection of environmental, social, and economic dimensions of housing sustainability contributes to the broader literature and provides insights for countries facing similar challenges in developing sustainable cities and resilient communities.