Effects of strengthening projects carried out in reinforced concrete buildings on architectural

Turkey's location on an active tectonic belt exposes the existing building stock to a high level of seismic hazard. The devastating earthquakes in recent years have clearly revealed that a significant portion of these buildings were not constructed in compliance with current seismic codes, and that their structural performance is inadequate. This situation poses a serious threat not only in terms of structural safety but also with respect to urban policies aimed at earthquake-resilient cities. Qualitative deficiencies such as poor material quality, inadequate workmanship, and lack of inspection further diminish the seismic resistance of buildings. Considering economic constraints and social dynamics, demolishing and reconstructing the entire existing building stock is not a feasible short-term solution. Therefore, seismic retrofitting strategies emerge as a priority solution within the scope of sustainable building management. Retrofitting methods aim not only to enhance the stiffness and energy dissipation capacity of structural systems but also to improve the overall performance of buildings. Advances in structural engineering and numerical analysis techniques now allow for more accurate modeling of building behavior and the grounding of intervention decisions on scientific bases. However, the retrofitting of reinforced concrete buildings should not be evaluated solely within the framework of the engineering discipline. Such interventions directly and indirectly affect the architectural character, spatial organization, aesthetic qualities, and user comfort of buildings. Hence, architectural design and structural interventions must be addressed through an interdisciplinary and holistic approach. Retrofitting projects should be regarded not only as a technical necessity but also as a critical field of intervention for preserving architectural continuity, maintaining urban aesthetics, and contributing to spatial quality. This doctoral study aims to analyze the effects of seismic retrofitting projects in reinforced concrete buildings on architectural design from a multidimensional perspective. The research identifies the impacts of different retrofitting methods on architectural qualities, evaluates their relationship with structural performance, and develops an interdisciplinary integration model. The findings emphasize the necessity of a retrofitting approach in which architectural and structural decisions are coordinated, ensuring that safety, aesthetic integrity, and spatial quality are preserved. The study seeks to contribute to the refunctionalization of buildings in a more resilient, livable, and sustainable manner, both technically and architecturally. Keywords: Reinforced concrete building, Seismic retrofitting strategies, Architectural design, Earthquake safety, Interdisciplinary approach, Sustainable building transformation