Architectural design, perception, and health in underground working environments

With rapid population growth and urbanization in recent years, the development of underground space has made great progress in many Asian cities. Going underground has several advantages, but at the same time underground spaces might create certain levels of environmental stress for human user. Design recommendations on mitigating negative psychological reactions in underground buildings have been summarized by different studies, e.g., introducing large, open spaces, designing entrance to create mild transition from aboveground environments. The design of transitional areas and the impact on human perception in underground buildings, however, have not been systematically investigated. This study provides a detailed evaluation on the interrelationship between architectural design, environmental perception, and health outcomes in underground office buildings. The effect of gender on the environmental perception - health relationship was explored. Key architectural design aspects on mitigating negative perceptions of underground work environments were identified. A questionnaire survey was conducted in 4 underground office buildings in Singapore, with 121 persons participating. Results of the questionnaire survey were processed with statistical analyses including bivariate correlations, moderation analyses and multiple regression models. The results showed that perceived confinement in the office has a negative effect on self-assessed mental health functioning, and male employees are more sensitive to such an effect than female employees. Both the design of office and transitional area are linked to perceived confinement in office. Ranking from the most important to the least, the significant predicting variables are the perceived difference between transitional area and office, length dimension of transitional area, spatial dimension of office, and thermal environments in office and transitional area. This study would inform future design and evaluation of urban underground spaces and promote healthy underground working environments.