The Role of Visual Connectivity in Shaping the Concept of Domain in Historic Houses of the Qajar Period in Rasht

The houses of the Qajar period in Rasht are valuable examples of traditional Iranian houses with different spatial configurations from those of other parts of Iran. Visual connectivity is a crucial factor in shaping the concept of domain in residential spaces. Houses have different visual qualities according to their designs and provide different experiences of space. This study aims to investigate the concept of domains by analyzing indicators of visual connectivity of indoor relationships in these houses. The research uses the descriptive-analytical method with logical reasoning of software outputs. In the first step, the houses were divided into four groups according to their designs, and then two samples were selected from each group with a total of eight. For coherence purposes and the comparative study of the samples, three common spaces of the veranda, reception room, and bedroom were analyzed. In the second stage, visual quality indicators including visual connectivity, viewing distances, and intelligibility were extracted from the research literature. In the third stage, visibility graph analysis, axial maps with cones of vision, axial lines, and connectivity and integration diagrams were produced in the Depthmap software. The results show that the visual connectivity values of spaces are different resulting in the creation of perceptual domains and spatial hierarchies. By examining the visibility cone indicators in the houses, it was observed that more adjacency with walls, less spatial complexity because of convexity of shape, and visual and physical accessibility make a space (such as the veranda) more connected with other spaces. On the other hand, lower values of the mentioned indicators create more privacy (such as in the bedrooms). Therefore, the indoor spaces of the extroverted houses of Rasht, while transparent, have visual and spatial boundaries that create a hierarchy of domains.