Practice of net Positive Energy House in the Suburb of Tokyo

To satisfy the energy saving standard will be mandatory for all architecture until 2020 in Japan. Furthermore, after the Tohoku earthquake in 2011, the positive energy house has been paid more attention to. ZEH, means “Zero Energy House”, is the significant key word for the Japanese. An advanced ZEH in the suburb of Tokyo was planned by authors. The novel point in the design process was the confirmation of the effects of passive and active system by simulation at many phases, even if the target was a small house. At first, we analyzed the local weather data recorded in Expanded AMeDAS Weather Data to decide the appropriate volume and position on the site. Secondly, we proposed the better level of thermal insulation than the level of the energy saving standard in Japan. The average U-value of the standard house in the located region was 0.87 W/m2·K, but the value of our planned house was 0.35 W/m2·K. Thirdly, we confirmed the effects of passive strategies and the high-efficiency equipment, such as the control of solar heat gain and daylight around the windows in all seasons, cross-ventilation, mechanical ventilation with heat exchanger and photovoltaic panel, judging the simulated results from EnergyPlus, Radiance, CFD and the program for calculating primary energy consumption of each usage in house made by the Japanese ministry. After the completion in February 2016, we have been measuring the power consumption of each circuit breakers, total gas and water consumption and indoor environment. The amount of real energy use and generation was shown to confirm the achievement of real ZEH or net positive energy house.