The impact of tangible and intangible factors on occupants’ satisfaction with the indoor environment: A machine learning-driven analysis

¹ Department of Real Estate and Construction, Faculty of Architecture, The University of Hong Kong, Hong Kong, China
² College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China

Abstract

Indoor environmental quality (IEQ) significantly impacts occupants' comfort, health, and cognitive performance. It includes both tangible factors—such as thermal environment, air quality, lighting environment, and acoustic environment—and intangible factors, such as space design. Despite their importance, intangible factors have received considerably less research attention than tangible ones. This study investigates how both types of factors influence occupants' satisfaction with the indoor environment. A questionnaire survey was conducted among dormitory residents, yielding 921 valid responses. The data were analyzed using XGBoost and other machine learning models, with XGBoost achieving a classification accuracy of 93%. To interpret the model results, we applied Shapley Additive Explanations (SHAP), which allowed us to assess the contribution of each factor to occupants' satisfaction with overall indoor environment. Notably, space design—an intangible factor—emerged as the most influential factor. The findings emphasize the critical role of intangible factors in shaping occupants' satisfaction with overall indoor environment, offering a fresh perspective on understanding occupants' satisfaction. Overall, this study provides practical insights for designing and managing more satisfying indoor environments, especially in dormitory settings.