The global imperative to address climate change and resource depletion requires innovative and sustainable strategies in the construction sector. This paper explores a methodological approach for integrating Circular Economy (CE) principles into the regeneration of the built environment. It places particular emphasis on adopting a comprehensive, transcalar perspective to ensure effective implementation. Redefining the traditional linear model of construction, the adoption of CE in building regeneration seeks to minimize waste, optimize resource use, and promote long-term resilience, in line with EU directives promoting sustainability and circularity in the built environment. The presentation will explore the key aspects of a circular design approach, including an application case study that examines the regeneration and adaptive reuse of a craft/residential neighborhood in Prato. Through a comprehensive analysis of existing literature, a series of circular design principles were identified. Circular strategies are declined according to the different scales of design: from urban environments to building-scale choices and construction materials and techniques, providing insights into indicators for assessing circularity. Different regeneration scenarios are assumed and compared according to a multi-criteria approach, based on circular design principles, in order to achieve sustainable regeneration results and highlight the benefits of adopting circular strategies at different project scales. The analysis framework considers the entire life cycle of the regeneration process, from design and construction to operation and end-of-life. The integration of a simplified Life Cycle Assessment (LCA) will provide a systematic evaluation of the environmental impacts associated with the entire life cycle of a building. LCA will be employed to assess the environmental implications of various building materials, construction processes, and end-of-life scenarios, guiding decision-makers in making informed choices that align with circular and sustainable principles. In conclusion, this presentation aims to explore an approach toward the circular transition in built environment regeneration. By adopting a global and multilevel perspective, we can actively contribute to a future that is environmentally sustainable and resilient and that meets the need, also addressed by the European Union, to move from a linear to a circular development model.