The article "Retrofitting Existing Buildings for Sustainability: Challenges and Innovations" by Obinna Iwuanyanwu, Ifechukwu Gil-Ozoudeh, Azubuike Chukwudi Okwandu, and Chidiebere Somadina Ike explores the critical strategy of retrofitting existing buildings to enhance sustainability. The authors highlight the environmental, economic, and social benefits of this approach, including reduced energy consumption, carbon emissions, and improved occupant comfort. However, they also identify significant challenges such as technical, financial, regulatory, and logistical obstacles. Despite these challenges, innovations in sustainable retrofitting, such as advanced HVAC systems, high-performance insulation, renewable energy sources, and smart building technologies, offer promising solutions. The article provides case studies of successful retrofitting projects in historical, commercial, and residential buildings, demonstrating the feasibility and benefits of sustainable retrofitting. It also discusses future trends and opportunities, including advancements in technology, regulatory support, and the growing market for green building certifications. The authors emphasize the importance of continuous innovation, investment, and collaboration among stakeholders to achieve a sustainable built environment.The article "Retrofitting Existing Buildings for Sustainability: Challenges and Innovations" by Obinna Iwuanyanwu, Ifechukwu Gil-Ozoudeh, Azubuike Chukwudi Okwandu, and Chidiebere Somadina Ike explores the critical strategy of retrofitting existing buildings to enhance sustainability. The authors highlight the environmental, economic, and social benefits of this approach, including reduced energy consumption, carbon emissions, and improved occupant comfort. However, they also identify significant challenges such as technical, financial, regulatory, and logistical obstacles. Despite these challenges, innovations in sustainable retrofitting, such as advanced HVAC systems, high-performance insulation, renewable energy sources, and smart building technologies, offer promising solutions. The article provides case studies of successful retrofitting projects in historical, commercial, and residential buildings, demonstrating the feasibility and benefits of sustainable retrofitting. It also discusses future trends and opportunities, including advancements in technology, regulatory support, and the growing market for green building certifications. The authors emphasize the importance of continuous innovation, investment, and collaboration among stakeholders to achieve a sustainable built environment.