Privacy is one of the fundamental principles of Iranian–Islamic residential architecture, the realization of which is directly related to the organization of spatial structure within houses. However, the physical–spatial transformations of the past century have altered residential patterns and weakened certain traditional principles underlying the achievement of privacy. This study aims to examine and analyze the spatial structure and privacy components of residential houses in the city of Dezful, seeking to comparatively elucidate the trajectory of transformations in spatial privacy. It also addresses the question of how changes in the spatial structure of Dezful’s residential houses across historical periods have influenced the degree of spatial privacy, and to what extent these changes can be explained through space syntax indicators. The research adopts a mixed analytical–comparative and case-study methodology. Samples were spatial privacy, and to what extent these changes can be explained through space syntax indicators. Samples were selected through non-probability purposive sampling from residential houses belonging to three historical periods. Spatial structure analysis was conducted using the space syntax approach and Depthmap. The findings indicate that Qajar-period houses exhibit deeper spatial structures, lower integration in private spaces, and greater control over access routes. These characteristics contribute to a higher level of spatial privacy and demonstrate that the realization of privacy in Iranian housing depends less on formal appearance and more on the logic, and the degree of privacy realization. The findings indicate that Qajar-period houses exhibit deeper spatial structures, lower integration in private spaces, and greater control over access routes.