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Thermal comfort in office buildings is instrumental in improving the productivity of employees while maintaining their health. The primary objectives of this research were to analyze the comfort temperature in Japanese office buildings and investigate its relationship with outdoor air temperature. Additionally, we examined the differences in comfort temperatures with respect to closed and opened windows to factor in the increase in the opening of windows during the COVID-19 pandemic when air-conditioning systems were operated. We investigated the environmental conditions of office buildings and the thermal comfort of the occupants through monthly visits to each office building over a year. Field data were collected from four office buildings located in Nagasaki City, with 1047 votes obtained from 143 participants. The survey indicated that the occupants were highly satisfied with the thermal environment in their offices. The correlation between indoor comfort temperature and outdoor temperature was high in the FR mode. Based on the analysis, we developed an adaptive model for office buildings in Nagasaki City and compared it with existing adaptive models used for buildings in other regions of Japan. The proposed model is useful for energy-saving designs that bring out human adaptive capacity.

This study focuses on the behavioural aspects of the occupants in Japanese office buildings. The behavioural adaptations such as window opening, heating/cooling use, clothing adjustments are important contributor factors for the adaptive thermal comfort. Therefore, understanding the behavioural aspects of the office workers can lead to have the guidelines to explain the mechanism of the adaptive model. The main aim of this study is to identify the differences in behavioural adaptation of the occupants in Japanese office buildings. Environmental parameters such as air temperature, relative humidity, and so on were measured in five mixed-mode office buildings located in Aichi prefecture were analysed for 15 months’ survey with 35 occupants. Thermal comfort survey together with the occupants’ behavioural survey were conducted in these office buildings. An adaptive relationship can be derived to estimate the indoor comfort temperature estimated by Griffiths method from the prevailing outdoor temperature. The results suggest that the proportion of heating and cooling use is related to the outdoor air temperature. The proportion of clothing adjustment is different for the different modes and are correlated to the outdoor air temperature. The acknowledge of the adaptive thermal comfort and the occupant behaviour of the selected buildings will be fruitful in designing the building with maximum thermal comfort in the future.

This study was undertaken to investigate seasonal adaptation to temperature in Japanese offices, with a view to suggesting an adaptive model for them. We measured temperatures in seven office buildings and conducted thermal comfort transverse surveys of occupants for over a year in the Aichi prefecture of Japan. We collected 1,228 samples. The occupants were found to be highly satisfied with the thermal environment in their offices. Even though the Japanese government recommends the indoor temperature of 28 °C for cooling and 20 °C for heating, we found that the comfort temperature was 2.8 °C lower in cooling mode and 4.3 °C higher in heating mode, in line with the actual indoor temperatures. The monthly variation in the temperature in the investigated offices was significantly lower than had been found in dwellings. An adaptive relationship can be derived to estimate the indoor comfort temperature from the prevailing outdoor temperature for similar office buildings.

Malignant neoplasms, cardiac disease, and cerebrovascular disease are Japan's most common causes of death, with cardiac disease and cerebrovascular disease increasing during the winter season. The indoor environment of Japanese houses is poor in winter. To reduce medical costs for the further aging of the population, it is essential to study the relationship between mortality and the indoor environment. This paper analysed mortality rates by location, age group, year of death, and energy efficiency classification to clarify the relationship between climate and mortality rates in each region. Data were constructed by merging mortality data with climate data. Mortality sensitivity measures the mortality rate increases when the outside temperature falls by 1 ˚C. We also found that mortality among those who died in residential settings was more strongly affected by the cooler outside temperature environment than in nonpresidential settings. It suggests that the mortality rate was more strongly affected by residential areas, which tend to have cooler indoor temperatures during the winter, than non-residential buildings such as hospitals and elderly care facilities. The analysis by age group showed that the sensitivity was higher for older age groups and warmer energy efficiency classification categories in Kyushu and Okinawa.

Japan's goal of becoming carbon neutral by 2050 requires both efficient use of facilities and maintenance of comfort for office workers in office buildings. In this paper, we clarify comfort temperatures from adaptive model in an office building in Hokkaido, as well as examine the factors that influence a more comfortable office environment. In the thermal comfort declaration, “Neutral” was the most declared in the MX mode (ventilated environment regardless of heating/cooling use), and the office workers were satisfied with the thermal environment. The comfort temperature was around 25°C in both MX and HT modes (heated environment), and a positive correlation was observed between the comfort temperature and the moving average outdoor temperature in MX mode, which led us to propose an adaptive model. Although the outdoor temperature in this model was about 8 °C lower than in previous studies, the comfort temperature was within the same range. There was no correlation between the amount of clothing worn by workers and their perception of cold and heat, but there was a positive correlation with the amount of activity.

Recent years, the mid- and high-rise wooden building using cross-laminated timber (CLT) is on the increase in the world. In the regions highly subjected to seismic events, it is important to know the basic property of the vibration of the building to design the building to be safety enough against the seismic load; however, there is enough such data of full scale wooden buildings. In this paper, the natural period, the damping ratio, and the mode shape of a full-scale five-story wooden building are evaluated using subspace identification method. The results show that the damping ratios of higher modes tend to be lower than that of the first mode, and the natural period and the damping ratio show amplitude dependency even in the range of low amplitude.