This study examines the relationship between personality traits and workplace preferences in the hybrid work era using the Big Five theory. A questionnaire survey was conducted among employees in a firm having work flexibility. The results show that individuals with higher neuroticism and openness tend to prefer working from home over the office. Differences in preferences also vary by task type and environmental factors such as noise, crowding, and lighting. The findings suggest that workplace preferences differ by personality, highlighting the importance of work policies and diverse workplace environments tailored to individual characteristics and task requirements.

The effects of lighting conditions on activity coexistence in a living space were examined from the following 3 aspects.

1. Eye-tracking was used to analyze visual behavior, and gaze distribution, dispersion, and spatial clustering were quantified using Shannon entropy and Moran’s I.

2. Subjective psychological responses were evaluated through questionnaires and visual analogue scales (VAS), focusing on discomfort and visual fatigue.

3. By comparing high- and low-luminance conditions, relationships between visual behavior and subjective evaluation were clarified, and differences in visual stability and perceived interference were interpreted.

This study investigates the indoor environmental conditions of low-income households in Hokkaido. Winter indoor environmental problems and their influencing factors were analyzed, and the Energy Poverty Index (EPI) was calculated to examine the relationship with energy expenditure burden. The results show that most detached houses maintained comfortable indoor temperatures, although low-income households tended to rely on individual heating. Public housing also maintained warm indoor conditions. However, window condensation exceeded 90%, EPI was high, and deprivation in food and clothing was more prevalent than heating deprivation, suggesting that maintaining heating may place pressure on other household expenditures.

This study conducted a residential stay-based experiment to examine the health effects of improved indoor air quality. A four-day, three-night experiment was carried out in two experimental houses, one designed with low-emission building materials. Forty participants took part, and VOCs were measured using passive samplers, while TVOC concentrations were continuously monitored. Questionnaires, biometric data, and activity records were collected to examine links between daily activities and air quality fluctuations. Results showed that reduced building-derived chemical concentrations suppressed symptom onset and that air quality varied dynamically with daily activities, highlighting the importance of continuous air quality monitoring beyond environmental design.

Whole life carbon (WLC) assessment toward achieving net-zero by 2050 in existing urban districts were conducted. Four consecutive investigations were conducted: (1) an overview of decarbonization trends and methodological framework, (2) data collection of the target district and its building stock, (3) comparative WLC assessment of two scenarios—rebuilding after 60 years and retrofit-only—and (4) development of a Net-Zero District Priority Index (nZPI) integrating operational carbon, embodied carbon, and residual building lifetime. The findings emphasize the importance of retrofit-first approaches, life-cycle-based urban planning, and data-driven tools for managing WLC at the urban scale.