An Empirical Evaluation of Building Orientation on Shadow-Sunlight Dynamics and Energy Performance in the Urban Fabric of Siirt 

People need energy to perform their daily tasks more easily. Developments such as population growth, demand for comfortable living conditions, industrialization, technological advancements, etc., increase the need for energy. The growing energy demand and sustainability requirements make energy efficiency mandatory in building design, and in this sense, "building orientation" stands out as a critical design parameter. In this study, numerical simulation and modeling methods were determined to evaluate the environmental performance of a residential settlement built by the Housing Development Administration (TOKİ) in Evren Neighborhood within the urban fabric of Siirt. The analyses were carried out using the Autodesk Revit Simulation software within the scope of Building Information Modeling (BIM) integration, aiming to empirically assess the impact of shadow-sun dynamics created by building orientation on energy performance. Through the empirical evaluation, it has been proven that the building orientation parameter plays a decisive role in energy efficiency. The required angle for ideal energy performance has been determined, and it has been found that southeast façades are more efficient than southern ones, and main living spaces should be positioned in this direction. Consequently, it has been determined that optimal building orientation is critical in reducing energy losses and improving the energy performance of buildings, and that BIM- based simulations are an effective tool in developing energy-efficient designs.