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• Method was established to model building stock composition in adopted technologies. • Stock model can estimate the baseline development of building stock. • Building stock energy models can be constructed to use building stock data. • The Japanese technology deployment trend can significantly reduce CO 2 emissions. • Efficiency measures help avoid the increase in electricity demand by electrification. A significant improvement in the building stock energy efficiency is imperative to mitigate climate change. Building stock energy models (BSEMs) that employ reference building models are useful for mitigation analysis. However, most existing BSEMs developed for commercial building stock focus on limited building systems and energy conservation measures, and technology deployments are suggested based on simple vintage-driven scenarios. These approaches are insufficient, particularly for regions where improvements to building insulation performances can have a modest impact. This study aims to establish a BSEM framework to overcome this issue and to validate the framework via its application to the Japanese commercial building stock. The framework develops statistical models for estimating the selection probabilities of system alternatives and utilizes them to disaggregate building stocks. A reference building model is developed for each stock segment. The results show that this approach facilitates the use of multiple technological options considering various factors that affect technological deployments, and it also helps estimate the baseline development of building stocks. Furthermore, the developed model well represents the observed distributions in energy use intensity and estimates the aggregated energy consumption of building stocks with a reasonable accuracy. The baseline development was estimated to reduce the CO 2 emission by 18% by 2030 from 2013. Efficiency measures can help avoid the increase in electricity demand caused by electrifying the heat source of heating, ventilating, and air-conditioning and water heating systems. The framework could help extend the scope of BSEM application because BSEM development is not information intensive. [ABSTRACT FROM AUTHOR]

• A numerical model is developed to study indoor thermal conditions during heat waves. • Moisture buffering can have an important influence on the indoor thermal conditions. • Pre-cooling before the start of a heat wave can lower indoor temperature moderately. • Moisture-desorption cooling has a large potential in reducing indoor heat stress. Urban areas are increasingly impacted by the urban heat island effect, especially during heat waves. In the context of improving energy efficiency in buildings, passive and energy-efficient cooling methods are needed for reducing indoor heat stress and lowering building energy consumption during heat waves. In this study, a whole building simulation model that includes both moisture and heat transport in wall envelopes and indoor environment is developed. An analytical solution and two test cases are used to validate the developed model. The developed model is applied to study indoor thermal conditions in urban areas in Zurich, Switzerland in a hot summer. The results show that indoor temperature could not be accurately simulated when moisture transport in the wall envelopes is neglected. Due to the urban heat island effect, night ventilation is not sufficient to cool down the indoor environment during the heat wave in the urban area. The potential of precooling before the heat wave and moisture-desorption cooling from hygroscopic materials have been studied to reduce indoor heat stress in the urban area. The average operative temperature during the heat wave can be reduced by 0.43 °C by precooling before the start of the heat wave, whereas desorption cooling from hygroscopic materials could reduce the average operative temperature during heat waves by 1.31 °C. A combination of these two mitigation measures could lead to enhanced passive cooling effect. There is a large potential of using desorption of hygroscopic material to reduce heat stress during heatwaves, while minimizing energy consumption of buildings. [ABSTRACT FROM AUTHOR]