Designing a third place in urban underground space

Places where people spend time between home (First Place) and work (Second Place) are called Third Places. People exchange ideas, have a good time, and build relationship there. Having overcome the COVID 19, social interaction and good places to do it become a major concern of urban life. Undergrounds space, a rapidly developing public space in metropolitan cities serve such a third place in useful and efficient way. This study focused on how users respond to various types of third places with or/and without sound to propose design criteria for unban underground third places. This study was conducted through field investigation and experimental surveys. Our researchers regularly visited urban underground space near large subway stations on weekdays and weekends in Busan, one of Korean metropolitan Cities to observe user behavior. We created 3D Models of four types of Third Places - Convenient zone, Greening zone, Water friendly zone, and Entertainment zone and produced them as videos. Ten subject each in their 20s, 30s, 40s, 50s and 60s participated in the experiment that measured prefrontal alpha EEG asymmetry while watching the videos, and to evaluate convenience, comfort, accessibility, safety, and interactivity of each type of third place. In this study proposes planning criteria for the third place of underground space where pro-social activities are conveniently performed. Various types of third places with appropriate acoustics provide users a pleasant and comfortable city life.