Practical Implementation and Social Significance of Localized Low-Cost Airtightness Retrofits in Existing Condominiums: In the Context of Decarbonization, Energy Justice, and Well-being

Abstract

text紀要論文 / Departmental Bulletin PaperThis study investigates the impact of localized airtightness and insulation retrofitting on the indoor thermal environment of three frequently used private rooms within an existing owner-occupied condominium unit in Japan. Targeting commonly neglected areas such as air conditioning pipe penetrations and ventilation inlets, the research combines thermographic analysis with pre- and post-retrofit temperature measurements, compared against outdoor conditions. The results reveal a substantial improvement in minimum indoor temperatures after the retrofit, with the indoor-outdoor temperature gap averaging 12 to 15°C during colder periods. In several cases, peak indoor temperatures also exceeded outdoor levels, indicating improved heat retention and daytime thermal performance. These findings suggest that even small-scale, low-cost interventions—when guided by careful observation and resident input—can lead to meaningful enhancements in comfort, health, and energy efficiency within existing buildings. The study positions this case as a practical model for promoting thermal equity and well-being, particularly in the context of climate change adaptation and decarbonization. Furthermore, it highlights the importance of resident engagement and empirical, evidence-based evaluation in informing future support mechanisms, policy development, and institutional frameworks aimed at inclusive and sustainable housing improvements.departmental bulletin pape