This contribution proposes a study on an innovative architectural and urban design model to address issues related to the challenges of climate change. It supports the adoption of green technologies, guided by the principles of Life Cycle Thinking and circular design, backed by data from the IPCC’s Sixth Assessment Report. The method integrates the strategies of the National Climate Change Adaptation Plan (PNACC) and uses parametric digital tools for project evaluation. It emphasizes climate adaptation through nature-based solutions and green technologies, especially in the Mediterranean context. Using Life Cycle Assessment (LCA) criteria, the methodology evaluates materials and components for their circularity, performance, and CO2 emission reduction potential, with the aid of digital tools. Two case studies, a temporary architecture (The People Pavilion) and a residential project (UNI17 Village), demonstrate the effectiveness of eco-design principles for climate adaptation. Sustainability assessment, drawing on original research methods and decarbonization methodologies, is central to the experimentation. Circular design principles, in line with PNACC goals, offer a technical and critical approach from predesign to implementation, focusing on waste reduction, upcycling, and closed-loop systems that use biogenic materials. The study concludes by highlighting the transformative potential of a multiscalar and circular approach in architectural design, providing a critical foundation for future interventions towards decarbonization and transition architecture.