The Theoretical Foundations of Adaptive Reuse of Historic Buildings: From Classical Theories to Modern Charters

The concept of adaptive reuse of historic buildings has become a key topic in cultural heritage conservation in recent decades. Originating from postmodern architectural movements, this approach is closely linked to sustainability, energy management, and functional adaptability. In many developed and developing countries, increased awareness of cultural and environmental values has highlighted this approach as a means to preserve historical identity while addressing contemporary needs. This article analyses the theoretical and philosophical foundations of adaptive reuse through a review of library and archival sources. It examines the thoughts of key figures in 19th-century conservation and restoration, such as Eugène Viollet-le-Duc and John Ruskin, who presented two different yet influential approaches in shaping building conservation principles. Their theories on authenticity, reconstruction, and historical continuity are explored, and their impact on contemporary conservation doctrines is assessed. Additionally, the study analyses key charters like the Athens Charter (1931) and the Venice Charter (1964), examining how conservation principles have evolved in response to modern challenges, including social transformations, industrialization, and environmental requirements. The aim of this study is to provide a comprehensive perspective on the theoretical foundations of conservation and adaptive reuse, serving as a reference for developing sustainable strategies in adapting the use of historic buildings.