In Japan, the name Kevin Meyerson is synonymous with passive houses. Meyerson, who moved to Japan from the USA in 1988, is the proud owner of a certified passive house in Karuizawa, Nagano. 

After writing about the ins and outs of his abode in our introduction to passive houses, we sat down with Meyerson to delve a little deeper into all things energy efficiency.

What sets your passive house apart from other passive houses in Japan?

Researchers from the University of Tokyo did a study based on three years of real-world data and found Karuizawa Passive House (my home) to be primarily energy positive. In other words, our house produces more energy than we consume. Further, according to Passive House Japan's Eco-Map, our house was the most energy efficient up till recently. 

What was behind the drop in rank?

It's simply that newer houses are even more efficient. Karuizawa Passive House is still among the best in Japan, though. 

How long have you been living in your passive house? Any plans to move?

My wife, dogs and I had the house designed and built in August 2012. We love living here and will probably be here for much longer. We may move in the future as we grow older, but no plans now.

Once you live in a passive house, you'll never want to live in anything less.

What's the best part of living in a passive house?

Above and beyond all the energy efficiency benefits, it's just so much more comfortable.

We have a two-storey house with a rooftop window, big south-facing windows, a wood-burning stove and floor heating. [In the cold months], we only burn one bundle of wood every few days (far less than our neighbours), and we run the floor heating maybe four times a year — basically just to make sure it's still working. 

It might be zero outside, but it will be 15 degrees Celsius inside the house. 14 was the coldest we ever had it, and that was when it was -15 outside! Most Japanese houses are much colder in winter — almost the same temperature indoors as out, and only one room is heated and usable.

My whole house is usable all year round; there's never a shock going from one room to another, even when the outside temperatures are extreme. In summer, the biggest temperature differential I've had was three degrees, which was between my first floor and the attic (which is normally a much hotter part of a conventional house). 

Would you build another passive house? 

I would absolutely build another passive house if I have the opportunity. The level of comfort is extremely high and I would have a hard time getting used to living in a normal building after having experienced living in a passive house.

Are passive houses MUCH more expensive to build than regular houses or buildings?

Passive house buildings are about 10-15 percent more to build than normal buildings. The cost difference shrinks as more architects and builders make more of them. From the first month, your utility bills will be up to 90 percent lower, though.

How do passive houses fit in with Japan's energy standards?

Japan doesn't really have any energy efficiency standards right now, but they should be put into place by 2020. They will still be weak compared to Europe, though. 

The average life expectancy of a regular house in Japan is perhaps around 35 years. They're built as disposable units, which benefits the housing industry but is bad for the environment. The flipside of this is that Japan has a chance to rebuild a huge number of houses in the next four to five decades, in a much more energy-efficient [and sustainable] way [such as passive houses].

Do you think a passive house beats out a smart house?

I am not sure, since I am not aware of a formal "smart house" standard. The concept of smart homes has been around for a while, and the passive house standard is compatible with the various smart house concepts. Passive House is a formal international standard based on concrete performance metrics.

What about earthquakes?

Passive houses, like other buildings, have to be built to earthquake (and fire) standards in Japan.

Would a passive house work in Tokyo?

There are already passive houses in Tokyo, Saitama, Kamakura and so on. Each passive house is designed based on the specific location, plot and temperature variables; the architect works within those constraints.

One thing is that the heat island effect in Tokyo is nasty, so you may need thick walls. That might decrease your overall floor space, but then, all of that floor space would be usable year round, unlike most other buildings [where you have to live in one heated or cooled room for much of the year]. 

Say you build a passive house in Tokyo, and then someone puts up a big building next door. Would that impact your passive house's performance?

The passive house standard is based on the time of being built. If things change around you, it'll affect the performance a bit, but your starting point for energy consumption is so low that even if you doubled it, you'd still be far lower than you ever would have been anywhere else, and the comfort level still far better than anywhere else too.

What else should people interested in building passive houses in Japan know?

A lot of architects here are amateurs in terms of energy consumption, but they might tell you they know how to build energy-efficient homes anyway — so you've got to do your research before signing them up. You'll find that many architects are actually more concerned about the look of a building than its comfort and performance. But the latter two are what determines whether people love their house or not.

What's your background, and what keeps you busy in Karuizawa?

I took a job after university at a Japanese publisher. In 1991, I started a digital media design production company called Rainbow Japan, and was president till 2012, when my business partner and I sold the company to our employees. From 2000 to 2009, I also started and was president of our subsidiary, Rainbow Partners Inc., which licensed the technologies that recognise music and display music metadata in Japanese and Korean consumer electronics devices. I sold the company in 2009 and retired in 2012. But after relaxing "too much," my wife asked me to get a job again! So I started a bar in Karuizawa in 2013 and still operate it. 

I am also chairman of Hon Karuizawa Kai, a community organisation trying to improve the area in several ways. Our first project is Karuizawa Basecamp Passport, a multi-mountain ski resort coupon booklet for 12 resorts in the area. I'm an avid skier.

Interview by Carey Finn

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