Application of Isovist analysis and sightlines in measuring visual quality of residential complexes (Case Study: Kermanshah City)

Like any other construction, a residential complex contains perceptual load for citizens as well as space and physical entity. Visual quality plays an essential role in the formation of this perceptual load. Thus, the perceptual function of a residential complex is dependent to a large extent on visual quality, which is considered qualitative, so the analysis involves plenty of complication. Isovist analyses and sightlines provide an efficient means of analysis and assessment of visual quality through quantitative methods. A review of the theories and studies presented in the field of isovist tools indicates their significance in the analysis of constructed environments based on the visual perception of the audience. This research provides an explanation of the relationship between isovist indicators and spatial experience. On the other hand, concern for visual privacy, which is a major aspect of the visual quality of the environment, is related to overlook. Moreover, whether the residential space is overlooked by surrounding buildings is an essential factor in specification of the interior space quality of a residential unit. The purpose of this study was to provide a method of using isovist tools and sightlines in the process of assessing the visual quality of residential complexes. The research was conducted in the city of Kermanshah, Iran. To this end, residential complexes located in Kermanshah were first typologized and categorized using analyses of form based on a quantitative method. For prevention of the inconsistency of the urban spaces around the complexes from functioning as an interfering factor, the shapes of the obtained types were then homogenized with the normalization method, and the spatial-physical quality of the normalized types was measured using Spacemate. In the next step, visual quality was assessed using isovist tools based on criteria including area, thrust angle, maximum line of sight, and circumscription, and quantitative data were extracted. Finally, the correlation between the data collected from the visual quality measurements and those obtained from the analysis of the spatial-physical quality of the types was examined and analyzed. The results demonstrated that each of the residential complex types involved specific visual quality indicators and sightlines that compared quantitatively and qualitatively with the other types. Moreover, the isovist indicators, which represented the visual quality of the types, correlated with their spatial indicators. This demonstrated the validity of the proposed method in isovist and sightline analysis for assessment of the visual quality of residential complexes, and illustrated the use of the Spacemate charts for that purpose. This research could not assign any of the types absolute or relative superiority in terms of visual quality; however, it analyzed the visual characteristics of each, thereby providing designers with a tool to include the desired visual qualities in their designs. The results of the research can be used potentially in the design of residential complex sites and, consequently, affect the quality of residential plans.