Influence of landscape outside the window on the anxiety level of self-separation people during COVID-19[Daily time spent indoors in German homes—baseline data for the assessment of indoor exposure of German occupants]

Windows are the communication medium between indoor and outdoor, but their influence and the corresponding landscape outside the window are often ignored due to the outdoor frequent activities of people. The coronavirus disease 2019 (COVID-19) has been a better choice to show the window performance, especially for the anxiety level alleviation of people isolated at home. A national survey was conducted on the anxiety of self-separation people and the window influence. The results showed that the average anxiety level was 1.54, between a little anxious and anxious, due to the COVID-19. The best satisfaction with the landscape outside the window was waterscape (2.98), followed by green plants (2.33) and buildings (0.83). During the COVID-19, the average number of overlook times increased by 1.49 times/day, which is higher 0.42 ties/day than the normal condition. The landscape types had the certain influence on the overlook frequency, the window opening times and even the anxiety level. The average anxiety levels are 1.36 and 1.68 with natural landscapes and human landscapes, respectively. Optimizing the landscapes outside the window plays an important role in alleviating the anxiety of residents and improving their mental health.