China's urgent need to retrofit 350 million residents' energy-inefficient housing faces critical coordination failures among diverse stakeholders. This paper investigates how digital platform principles, particularly those from Chinese super-apps, could enable community-driven sustainable housing transformations. Through systematic analysis of 27 digital platforms (15 Western, 12 Chinese) for housing services, we identify fundamental architectural divergences affecting retrofit coordination capabilities. Western platforms exhibit "fragmentation by design," prioritizing market competition over coordination efficiency, while Chinese super-apps demonstrate ecosystem integration but lack retrofit-specific mechanisms. Our analysis reveals five critical capability gaps: collective decision infrastructure, multi-stakeholder coordination, integrated compliance workflows, community benefit optimization, and trust beyond transactions. Based on these findings, we develop a conceptual framework comprising five interconnected modules operating above a unified data foundation: collective optimization (prioritizing community benefits over individual preferences), community coordination (structured decision-making), marketplace integration (trusted service provider connections), financial coordination (integrating diverse funding sources), and regulatory streamlining (proactive compliance support). The framework fundamentally inverts conventional platform logic from individual preference aggregation to collective benefit optimization, with algorithms weighting community outcomes at 80% versus individual preferences at 20%. This reconceptualization demonstrates how platform-mediated collective action becomes possible when technology design aligns with community social practices rather than imposing market logics, offering a pathway to accelerate China's sustainable housing transformation.