How does green coverage ratio and spaciousness affect self-reported performance and mood?

Abstract

Experiments were conducted to evaluate the effects of green coverage ratio and spaciousness on physiological and psychological responses at a resting space in an atrium. Ninety participants were engaged in the experiment that required cognitive tasks for 10 min with a 2-min virtual reality (VR) break. During the VR break, they experienced six different scenes which were three green coverage ratios (0%, 25% and 60%), two room volumes (940 m3 and 1713 m3), and two window sizes. The results showed that visual comfort, mood, self-reported recovery, and productivity were better in cases with greenery than without. Mean heart rate differences between the test and break periods were 3.1 bpm lower in the spaces with small window size than those with big window size. This suggested that participants might experience physiological stress due to low prospect in the spaces with high green coverage ratio and small windows. The relationships between green coverage ratio, spaciousness, and psychological responses such as environmental satisfaction, mood and self-reported performance were analyzed. Green coverage ratio and spaciousness had correlations to visual comfort, mood, and self-reported productivity as a polynomial approximation. Green coverage ratio showed a quadratic correlation with sadness, self-reported alertness, concentration, and recovery. Greenery and spaciousness contributed to visual comfort, mood, and self-reported productivity improvements.