Informal settlements in developing countries present complex challenges that demand a shift from conventional upgrading strategies. Existing research highlights growing disparities between developed and developing nations and between planned and unplanned urban areas, underscoring the urgency for sustainable solutions. Green building principles centered on ecologically responsible design, construction, and resource efficiency offer transformative potential for these settlements. However, current frameworks often neglect socio-economic, cultural, and technological integration, limiting their scalability. Additionally, minimal research explores how informal construction practices can align with green technologies to enhance affordability and community acceptance. This study examines the role of green building principles in upgrading informal settlements, assessing both opportunities and barriers. By focusing on energy-efficient retrofitting, sustainable materials, and community-driven initiatives, it assesses policy reforms, flexible building codes, and technological innovations through case studies such as Brazil, Ethiopia, and South Africa. Findings reveal a critical gap in holistic strategies and propose scalable, cost-effective solutions such as modular designs, localized material sourcing, and participatory engagement models to ensure inclusive housing for low-income populations. The transition to green buildings, though complex, is essential for sustainable urbanization. Success requires a multidisciplinary approach combining policy adjustments (e.g., subsidies for green retrofitting), technical advancements (e.g., decentralized solar systems), and active community involvement to address financial, governance, and social barriers. As cities in developing regions expand, prioritizing green construction in informal settlements is vital to fostering resilient, equitable, and ecologically sustainable urban environments. This study advances discourse by identifying key challenges, such as high upfront costs and fragmented governance, and opportunities, including job creation and long-term energy savings. It also highlights research gaps, such as the need for climate-resilient designs and digital tools for participatory planning. By providing actionable insights, the paper equips policymakers, researchers, and practitioners with strategies to develop context-sensitive, scalable green solutions for vulnerable urban populations. Ultimately, proactive investment in these approaches can mitigate urban poverty, reduce carbon footprints, and promote inclusive growth in rapidly urbanizing regions.
KeywordsInformal SettlementsGreen Building
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