View access index: The effects of geometric variables of window views on occupants’ satisfaction

One of the important aims of window design is to provide quality views that affect occupant health, well-being, and work performance. We assessed the effect of geometric variables (i.e., view angles, glazing area (Window-to-Wall Ratio, WWR), window distance, viewing direction and percentage of window view area in the visual field (PWV)) had on occupants’ satisfaction to view access. We conducted a human subject experiment with 40 participants using simulated images displayed in virtual reality headsets. Each participant rated 40 images with the geometric window view variables being presented in various combinations. The results showed that glazing area (WWR), window distance, and viewing direction were the three primary predictors for view access satisfaction. Based on the empirical results, we developed a view access index. This index found that satisfactory view access cannot be achieved with WWRs < ∼25%, and the level of satisfaction with view access did not increase substantially when WWRs > ∼65%. The proposed index is the first model that predicts occupant satisfaction to view access by considering the complex interplay of multiple geometric window view variables derived from an immersive environment. Given the impact of glazing area, window distance and viewing direction have on occupant satisfaction in the workplace, it is important to integrate them during the early stages of building design. For minimum view access requirements, we recommend WWRs and horizontal view angles that are greater than 25% and to 35°.