Rapid urbanisation across sub-Saharan Africa presents both opportunities and challenges, with cities like Lilongwe in Malawi struggling to accommodate population growth while addressing climate vulnerability and infrastructure deficits. This paper examines the transferability of Chinese eco-city principles, particularly the Sponge City Programme and green infrastructure approaches, to the Malawian urban context. Drawing on constructivist theories of policy diffusion and South-South cooperation, the study employs qualitative comparative policy analysis to assess the institutional, financial, and governance conditions shaping eco-urbanism in both countries. The study draws on recent scholarship on community-based flood adaptation in informal settlements to contextualise Lilongwe’s vulnerability within broader Global South patterns. The study finds that while Chinese eco-city models offer valuable technical innovations, their direct transplantation to Lilongwe is constrained by fundamental differences in institutional capacity, fiscal resources, urban governance structures, and land tenure systems. However, specific principles, including community-led green infrastructure, multi-functional public space design, and incremental retrofitting approaches, demonstrate potential for adaptation through what we term “Vernacular Eco-Urbanism.” This concept refers to the contextual integration of global best practices with local knowledge systems, institutional capabilities, and existing urban fabrics; prioritising function over form, incremental over comprehensive implementation, and participatory over technocratic decision-making. The paper contributes to decolonising urban studies by challenging unidirectional North-South policy transfer frameworks and proposing a more holistic approach to South-South urban learning that centres local agency and institutional realities.