Strategy-Oriented Seismic Rehabilitation of Existing Buildings: A Comprehensive Review and Decision-Support Framework

The seismic rehabilitation of existing buildings has become a major challenge in structural engineering due to the ageing of the global building stock, increasing seismic risk, and the growing demand for sustainable and resilient infrastructure. Although numerous retrofit techniques have been developed, most existing reviews classify solutions according to construction materials or individual technologies, providing limited guidance for selecting appropriate rehabilitation strategies in engineering practice. This review proposes a strategy-oriented framework that classifies seismic rehabilitation according to primary structural objectives rather than constituent materials. Five principal strategies are critically assessed: capacity enhancement, stiffness enhancement, ductility enhancement, seismic demand reduction, and hybrid rehabilitation. Their governing structural mechanisms, representative retrofit techniques, advantages, limitations, applicability, and sustainability implications are comparatively evaluated. Building on this classification, a decision-oriented framework is introduced that links structural typology, governing deficiencies, target performance objectives, rehabilitation strategies, and representative retrofit techniques, providing a structured basis for preliminary engineering decision-making before detailed structural design and verification. The review demonstrates that effective seismic rehabilitation depends primarily on the compatibility between the selected strategy and the characteristics and deficiencies of the existing structure rather than on any individual retrofit technique. It also highlights the growing importance of hybrid interventions, performance-based design, sustainability, functional recovery, and long-term resilience. By combining a comprehensive synthesis of current knowledge with a strategy-oriented classification and practical decision-support framework, this review provides a structured methodology for comparing and selecting rehabilitation strategies across diverse building typologies and project-specific constraints.