Design of net zero energy house and evaluation in the first year − The report of “Diagonal Boxes”, which received the grand prize of the 7th Sustainable House Award by IBEC −

This report introduces the design of a Net Zero Energy House in the suburban Tokyo and the evaluation result of the thermal environment and the energy consumption of it. Highly insulated and air-tight envelope, passive solar gain, sun-shading, daylighting and natural ventilation, thermal mass, highly efficient equipment and photovoltaic panels are applied to this house. In the design phase, the energy consumption and the amount of power generation was simulated. In the first year after construction, the actual amount of them was estimated by HEMS data, and it closely matched the evaluation in the design phase.