Contemporary Forms of Adaptive Reuse in Architecture: From Historic Monuments to Ephemeral Interventions

Architectural recycling has evolved from historical pragmatism into a vital tool for sustainability, currently driven by the climate crisis and EU policies such as The European Green Deal (EGD) and the New European Bauhaus (NEB). This paper maps the historical trajectory of architectural reuse. Its primary objective is to analyze contemporary approaches to adaptive reuse by comparing permanent, structurally intensive conversions with temporary, fully reversible interventions. The work places these two principles in counter-position and analyzes their mutual relationship. Based on a comparative analysis of European and Slovak case studies, projects are categorized by the degree of structural intervention and the duration of the new function. While conversion is an integral part of the circular economy in Western Europe, it is gradually emerging as an alternative to demolition in Slovakia. The research emphasizes the growing strategic importance of interim use. Temporary conversions, often requiring zero structural input, redefine existing spaces through scenography, mobile elements, lighting, or solely by introducing a new function. Results confirm that ephemeral interventions are effective tools for activating collective memory and testing a site’s potential prior to definitive restoration. Temporary adaptive reuse thus emerges as a viable, sustainable alternative to traditional conversion. It protects monuments from degradation, supports social innovation, and demonstrates that even a minimal, one-hundred-percent-reversible gesture can deliver maximum spatial and conceptual impact in the 21st century.