Circular thinking represents a fundamental departure from the linear model of the industrial era: extract, produce, discard. In its place emerges the concept of a closed loop in which products, components, and materials are maintained at their highest possible value and utility for as long as possible. Rather than focusing solely on material efficiency, circularity operates as a broader framework for sustainable development. It is reflected in everyday decisions, in prioritizing repair and sharing over new consumption, reducing food waste, and ensuring responsible material management. At the same time, it reshapes economic models and industrial processes. 

For Europe, a continent historically dependent on imported raw materials, circularity is not merely a choice but an existential necessity and a strategic response to global challenges. Contemporary industrial systems, characterized by high energy consumption and a significant environmental footprint, stand at the threshold of a necessary transformation. The circular economy proposes a more resilient, innovative, and competitive system, one that internalizes environmental costs while generating new forms of value, including stronger local economies, new employment opportunities, and greater social cohesion. 

Within this context, the construction sector becomes a crucial field for the implementation and testing of circular principles. As one of the largest consumers of global resources and producers of waste (generating more than one third of total waste in the European Union), construction must move beyond incremental improvements toward a fundamental redefinition of the building life cycle, from design and construction to management, transformation, and eventual disassembly. The challenge lies in shifting from a mindset of constant expansion and replacement toward the careful stewardship of the existing building stock, understood as a dynamic material bank for present and future generations. 

The practice of reusing building components, although often presented today as a progressive innovation, is in fact deeply rooted in the history of construction. From the reuse of ancient spolia to vernacular building traditions, where every available resource was used to its fullest potential, reuse was not an alternative but the norm, a pragmatic and cultural continuity within the built environment. This organic cycle was disrupted only with the rise of the industrial revolution and the accompanying fetishization of novelty, standardization, and mass production, which gradually devalued the existing and the reusable. The contemporary return to reuse is therefore not only a technical or logistical challenge. It touches the very foundations of architectural thinking, redefining architecture’s relationship to materiality, time, and resources.