The house is located in the Town of Karuizawa, roughly one hour by Shinkansen train from Tokyo. Karuizawa is a small town known for its winter sports facilities and is a retreat for many people from Tokyo during the summer as the climate is cooler and less humid.
Built for a couple, the owners wanted a comfortable house for themselves and their two little dogs.
The House has been planned and executed according to the standards set by the German Passive House Institute in Darmstadt, and, by using solar and biomass energy, the house is in fact a plus energy house, producing more energy than it requires. This is despite being located in the mountains more than 1000m above sea level. In this location conventional houses would require huge amounts of energy to preserve the quality of life of the inhabitants. The Karuizawa Passive House manages this by being well insulated and designed to absorb the maximum sunlight during winter on the South side whereas the North side has very little windows to prevent heat loss.