Study on thermal mitigation of the balcony by green curtains in Japanese condominium

¹ Dept. of Restoration Ecology & Built Environment, Faculty of Environmental Studies, Tokyo City University, 3-3-1 Ushikubonishi, Tsuzuki-ku, Yokohama 224-8551, Japan.
² Graduate School of Environmental and Information Studies, Tokyo City University, 3-3-1 Ushikubo-nishi, Tsuzuki-ku, Yokohama 224-8551, Japan.
³ Team Net Inc., Tokyo 155-0033, Japan.
⁴ Meiwa Estate Co., Ltd., Tokyo 150-8555, Japan.

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Increasing concerns over climate change, the pursuit of carbon neutrality has emerged as a key policy objective. Green infrastructure including “green curtains” is gaining attention due to its simplicity and effectiveness in urban thermal environments. Although previous research has focused on classrooms and urban spaces, there remains a lack of information on balconies, especially in new residential buildings. This study examines the thermal environment of a balcony and evaluates the effectiveness of green curtains on a recently constructed 8-storey apartment building in Tokyo. A thermal measurement survey was conducted from June to September 2025 using digital measurement instruments. The results indicate that the installation of green curtains led to measurable reductions in balcony temperature and improvements in occupant thermal comfort. These findings suggest that green curtains represent an effective, user-friendly strategy for enhancing thermal comfort in urban residential environments, offering practical implications for sustainable housing design.