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Friday, June 25, 2010

Japan's First Passive House

This simple yet elegant home by Key Architects is not just an intriguing example of modern Japanese design — it’s also is the first certified Passive House in Japan. Simplicity has its rewards, and when the Passive House standard is synthesized with Japan’s refined building sensibility the result is a powerful combination that can move green building to a new level. This ultra-efficient house is a far cry from traditional Japanese housing, which used thin wall construction and single-pane windows, which even today is still quit typical.
Key Architects‘ Passive House uses very detailed construction materials and building techniques to improve the shell’s r-value to the point where much of the interior heating is provided by the appliances and occupants of the building. This home is a great example of the Passive House standard’s building techniques — it features triple-pane windows, thick walls for insulation, and a minimum of exterior joints, which are prone to air leaks and thermal bridging. The core of the HVAC system is a HRV — or Heat Recovery Unit — that provides a constant supply of fresh, filtered air. A building becomes Passive House certified when, amongst other things it achieves a strict kWh per square-foot per year energy profile — in this case the home’s rating is ¼ of what is considered average.
The Passive House standard is becoming an important measure of sustainable building, and in Japan’s climate these homes would save an enormous amount of energy. This home is located about 50 miles southwest of Tokyo in the resort town of Kamakura city. Its design helps diminish the criticism that the ‘boxyness’ of many passive houses is not beautiful — and we also really like the roof deck.

(Text and images via)

This house is a very modest and pragmatic design, yet it is a good example of just how efficient single family homes can be. Given its economical construction methods, it could also act as a prototype for multi-family dwellings. Japan on average uses 69% less energy than the USA, but has technology in Robotics, Solar power, LED's that far surpasses the USA. Americans will unlikely be recycling bath water like the Japanese, but might wish to cut back on fossil fuels and conserve electrical consumption in order to save both money as well as greenhouse emissions. Culturally we may not be ready to give up life style changes quickly, but given the right energy efficient building methods that are becoming more and more affordable, we might not have to. The energy efficient home is also a great idea for those with second homes in the country that may not need to be heated and cooled all the time. As the technology evolves for energy generating technologies, residential homes may indeed become more dynamic in their shape and form - where the technology informs the shape, orientation, materials - while enhancing the overall design rather than detracting from it.