When Mr. Alexander Croft Shaw, a Canadian missionary, arrived in Karuizawa and built the first summer house in town in 1888, it might be enough to have a house with such a simple design and structure to spend only a summer season here. Today, Karuizawa has become one of the preferred places to live in the area, and how to find or build a good house which can cope with significant variation in temperature for seasons is becoming important.
I continue with my story on house building. Pictures from my house during construction are shown above. I discussed with my architect on how to maximize thermal insulation and earthquake-proof performance while minimizing construction cost. In the end, we adopted 25 cm thick of Rockwool insulation for a ceiling, 10 cm of Urethane insulation for walls, and triple glazed sash windows. According to the architect, it is rare to build a house with this level of insulation performance though it may be common in Hokkaido (northernmost island of Japan).
I have been living in my new house for almost a year since I moved in November, 2014. During summer, inside the room is very cool since the walls and windows shut out heat by sunshine. During winter, only one unit of a direct vent oil heater in the first floor heats all the rooms in both first and second floors. It is warm enough. Even when it is - (minus) 10 degrees in Celsius in the early morning outside, without turning the heater on, temperature inside the room is around (plus) 10 degrees in Celsius. It is not so bad. Since we do not use electricity to heat the house, energy cost went significantly down, compared to when I lived in my previous rental apartment. My electricity bill was roughly 40,000 JPY monthly during winter in the rental apartment with electric heating, but it is now less than 20,000 JPY monthly during the winter and even less during the summer. I think it is reasonable enough as an energy cost of standard independent house (i.e., non-condominium type residence).
My local friend, Kevin, is famous in town for promoting his house as "Passive House" where energy cost is actually, negative. See his story in Renewables International magazine. His house follows the German standard by Passivhaus Institut, and has 28 cm of insulation in walls and 60 cm in ceiling. By generating and selling electricity by solar panels on the roof, his house's energy cost is reportedly negative. It is incredible achievement in this severe seasonal environment.
Finding a stylish and design-conscious house should be easy in Karuizawa, when you search in real estate information services on the web. There are many architects who are advertising their capabilities to design luxury and modern taste villas. Appearance tends to be the most important factor for villa buyers, while the house performance tends to be overlooked. I hope more house buyers would care the house performance equally, especially if they care the quality of resort time in this relaxing town.