Linking window-view nature exposure with health and wellbeing outcomes: Using photorealistic 3D city models and computer vision technique

It is well established that nature exposure can improve both physical and mental health and wellbeing outcomes. However, in the context of rapid urbanization and high-density urban development, many urban residents face limited opportunities to visit natural environment, such as urban parks, greenways, and water bodies. In such situations, window view often serves as the primary means of people’s nature exposure. Traditional methods of assessing window-view nature exposure are time-consuming and labor-intensive, thus impractical for citywide evaluations. This study used a novel approach to quantify citywide assessment of window-view nature exposure, including the Window Greenery Index (WGI), Window Water Index (WWI), and Window Sky Index (WSI), using photorealistic 3D city models. We further analyzed the non-linear associations between window-view nature exposure with physical and mental health and wellbeing among 1,660 participants in Hong Kong for two periods: before and during the COVID-19 pandemic. For comparison, street-level nature exposure was also assessed. The result illustrates spatial mismatch between window-view and street-view nature exposure. Furthermore, window-view nature exposure had a greater influence than street-view nature exposure on physical and mental health and wellbeing. Furthermore, the effect of window-view nature exposure becomes more pronounced during the COVID-19 pandemic than before the pandemic. The results shed light on the link between window-view nature exposure and health and wellbeing outcomes, providing a new research front to understand the joint impacts of urban planning (i.e., provision of green space) and architectural design (i.e., location and orientation of windows) on public health.