Use of techniques for preservation, restoration and activation of historical castles and fortifications, depending on their degrees of destruction

The article describes eight different techniques for preserving, restoring, and revitalizing historic castles and fortifications. The relevance of this study lies in the urgent need for a systematic and differentiated approach to the preservation, rehabilitation, and adaptive reuse of historical castles and fortification structures, many of which today remain in a neglected or ruined state. Their advanced destruction requires not only technical stabilization but also thoughtful integration into modern cultural and urban contexts. The purpose of the research is to classify architectural techniques of intervention in accordance with the level of physical, functional, and spatial destruction of historic structures, offering a clear methodological foundation for the development of context-sensitive conservation strategies. It proposes a set of eight architectural techniques, both constructive and functional, each aligned with specific degrees of structural deterioration. These techniques are correlated with levels of material loss, architectural integrity, landscape disruption, and current functionality. Key assessment criteria include the condition of load-bearing elements, the authenticity of materials, the clarity of the spatial composition, the extent of modern alterations, the presence of historical detail, and the surrounding environment. This classification enables an objective evaluation of destrution and guides the appropriate selection of restoration or activation techniques. The system supports more flexible, balanced, and sustainable preservation planning, especially under constraints of limited resources and in regions where historical architecture plays a critical role in identity and tourism. The findings of this research are of practical significance for architects, preservationists, planners, and institutions working with heritage protection and the revitalization of culturally significant architectural sites.