Psychometric assessment of visual enclosure and walkability in intermediate urban spaces through virtual reality

Abstract Urban environments are complex systems influenced by spatial, visual, and functional factors. Walkability assessments often depend on subjective opinions and symmetric distance-to-height ratios, assuming that streets are framed by similar surfaces on both sides. This study used immersive virtual reality (VR) to examine visual enclosure in intermediate spaces, while maintaining a consistent stimulus for all participants and a 360° experience. Fifty-nine panoramas, taken at twenty stations along a 1.5 km route in Batna, Algeria, were converted into achromatic line images. Each station was coded for boundary type and two signed asymmetry indices, geometric and material. Ninety-six architecture students completed a twenty-item questionnaire at each station; fifteen items formed five reliable sub-scales, and the medium was widely accepted (92.7%). Participants reported both enclosure (80%) and openness (96%), which seemed to coexist, but rated legibility poorly. In an ordinal mixed model, greater permeability asymmetry between the two boundaries was linked to less favorable ratings (OR = 0.597, 95% CI 0.393–0.906), while geometric indicators were not; 3.5% of the variance was between stations. These exploratory findings, from a single route and a student sample, suggest that boundary permeability may deserve attention alongside height in street design, and that immersive assessment provides a practical way to study how urban space is experienced.