This book explores innovative approaches to sustainable urban development, focusing on energy efficiency, climate adaptation, green infrastructure, and smart city technologies. Addressing pressing environmental challenges, this book presents the most recent research on energy-efficient building design, urban resilience, and sustainable mobility solutions. The first section examines the role of energy efficiency in mitigating climate change, analyzing case studies on retrofitting buildings, passive architecture, and the impact of material choices. The second section explores urban climate resilience, highlighting the benefits of green infrastructure, street trees, and water-sensitive urban design. The third section shifts towards sustainable urban planning, emphasizing mobility transformation, cultural heritage preservation, and equitable urban design. The final section investigates digital tools and technological innovations, including smart cities, robotics, and circular economy practices in urban construction. By bringing together a diverse range of perspectives from architecture, engineering, and urban planning, this book provides actionable insights for policymakers, researchers, and practitioners committed to creating sustainable cities.