Evaluating the impact of windows, artificial windows, and ceiling height on stress levels through subjective and objective measures

Comprehending the influence of indoor environments on stress levels is critical for promoting well-being. This study examined how specific indoor design factors affect stress levels, focusing on four physical mock-up rooms: (1) a wall-only, (2) a window, (3) an artificial window, and (4) a higher ceiling height. Using a within-subject, counterbalanced design, 37 participants experienced each of these four rooms. Stress was assessed via subjective measures and electrodermal activity, electrocardiography, photoplethysmography, and electroencephalography. When the stress levels in the four rooms were compared, the participants in the rooms with a window presented significantly lower stress levels than did those in the three other rooms, with a wall-only, an artificial window, and a higher ceiling height. This finding underscores the benefits of having a window for reducing stress. While the stress levels in the room with an artificial window were slightly lower than those in the rooms with a wall-only and a higher ceiling height, these differences were not statistically significant. Interestingly, the room with a higher ceiling height presented varying stress levels relative to other rooms. The stress levels at higher ceiling heights were significantly higher than those in the room with a window. However, compared with a wall-only room or an artificial window room, stress levels in a room with a higher ceiling height statistically insignificantly differed and fluctuated depending on the type of stress measurement. This finding demonstrates that simply increasing the ceiling height is insufficient for achieving a low-stress indoor environment, underscoring the need for further research.