Passive Houses: A conversation with Kevin Meyerson

While doing research for our November 2014 Home Truths column in the Japan Times, we talked to Kevin Meyerson, who has lived in Japan for 25 years and recently sold his web design business in Tokyo and moved to Karuizawa in Nagano Prefecture, where he built a passive house. Our conversation about his new home lasted more than an hour, and, obviously, only a small part could be used in the article. Here’s a bit more.

-How did you find out about passive houses?

We bought land in Karuizawa in 2010 and I was going to commute to Tokyo. I wanted to build an environmentally friendly house. My company had gotten ISO 14001 certifications several years before and I became more aware of energy efficiency and environmental issues concerning the use of energy, so I wanted to build an energy efficient house and looked at Japanese smart houses. There’s a new Japanese standard being considered for 2020 and I looked into those houses, and then I found out about LEED in the U.S., which is similar to CASBEE here in Japan, and I talked to the LEED architect for a while and found out through him about passive houses and that there was an architect who just brought the standard to Japan. She built the first one in Kamakura in 2009. There’s about ten now in Japan and a bunch more under construction. It’s going really fast, actually.

The LEED architect’s comment sort of blew me away with regard to passive houses. “I could probably build you a house that could be heated by a single candle, but why would you want to do that?” But my thinking was, if you can do that why wouldn’t you? So I contacted the architect who brought the passive house standard to Japan and she was quite busy but we were in a rush, and about nine months later her schedule became open and she decided to take on the project.

-Is LEED a company?

No, it’s a standard in the U.S. In Japan there’s a similar kind of system, though it’s not really a standard. It’s a checklist: Do you have solar panels on your house? Do you eat organic? There’s a whole bunch of stuff indirectly related to environmentally sound living. It’s been adopted by some architects who want to make environmentally friendly structures.

-Is it like LOHAS?

It’s a bit more formal than that. The passive house is a very simple standard in that it’s extremely focused on energy consumption on a per-square-meter-of-floor-space basis. If you have a square meter of floor space in your house you can only use 120 kilowatt-hours of energy per year. There are a couple of other standards besides overall energy consumption, but it’s focused on reducing the amount of energy you use per square meter while maintaining a comfortable living environment. The LEED standard, like CASBEE in Japan, is broader. It’s not just about energy consumption. It’s about a whole bunch of things. Some people think that’s a better way to do it, but if you build a house that’s LEED-certified it still can consume a lot of energy, so some people have been criticizing LEED and CASBEE as being a means of looking environmentally friendly without actually being environmentally friendly.

-When you first decided to build a passive house, did you have a model you looked at?

I looked up a bunch of stuff on the net and found that the passive house standard is quite common in Europe. And it’s becoming more common in the U.S. as well. And in all the cases the comments of people who lived in passive houses was that they never knew how comfortable a house could be, or now that they live in one they couldn’t live anywhere else.

-Do you have a heat source?

It’s a misconception that passive houses are not heated, and that there’s no heat source. Our house has a floor heating system and a wood burning stove, as far as artificial heat sources go. The main heat source is the windows and sunlight and our bodies. And exhaust heat from cooking and the refrigerator. The thing with most houses is that you have so much heat lost through gaps in construction or lack of insulation that the small heat sources like your refrigerator or your body or taking a bath or cooking dinner, they don’t make much difference because so much heat is lost through heat bridges or gaps. Because a passive house is so well insulated in that the gaps are sealed, those heat sources make a difference. But they’re not perfect. In Karuizawa it gets to be minus 15 degrees in the winter, so you need additional heat. Our experience in the last two years had been that we burn one bundle of logs every two or three days. Most people here have wood stoves, which they use in conjunction with floor heating. And they would be burning logs all day long. In our case, we’ve found that our floor heating isn’t necessary. We’ve used it maybe six or seven times over the past two years.

-Is your floor heating gas or electricity?

We use an electric heat pump, which is quite efficient.

-How about heating water?

We have a gas heater. We wanted to use a solar water heater, and the architect wanted to do that, but the builder insisted that in Karuizawa it wouldn’t work properly. It turned out that that was false.

-What, he thought you wouldn’t get enough sunlight?

Well, that’s a different story in itself, the amount of sunlight. We couldn’t do it because the gas company wouldn’t allow us to preheat the water using a solar heater and then run it through the gas to supplement it, because that would have reduced our overall gas use. But, in fact, we got passive house certification from the German Passive House Institute, and ours is a positive energy house, but we would like to reduce our energy consumption even more, if possible, economically and regulatorily, but the rules from the gas company didn’t allow us to do that.

-Do you have any solar capability?

We have 4.2 kilowatts worth of solar panels, and that’s not part of the passive house standard, which is strictly about energy consumption, not energy production. So our house is not just a passive house, it’s also a PEB, or positive energy building. That means that the amount of energy that we consume is less than what we produce. And that’s not just in terms of electricity but overall energy.

-Do you sell your excess energy to the power company?

Yes, to Chubu Electric. In fact, we sell most of our electricity because our house consumes so little, and since we produce it most of it goes into the grid.

-The government has been trying to promote certain “eco” products. Were you eligible for any rebates or tax breaks through your house?

No. And it’s a real disappointment, what with the government that is in place right now. They are trying to promote long-term housing, meaning houses that last many, many years, but it has nothing to do with energy consumption. They have all sort of rules about construction but none of those things specifically address energy consumption. One of the things most people don’t realize is that most of the countries in the European Union have dictated that new construction must have a certain energy performance. It’s like regulating that cars get a certain amount of gas mileage. But in Japan there are no energy consumption standards in the building code. I’ve argued quite a bit with architects, and I speak sometimes at the University of Tokyo and at different symposiums. It’s ridiculous that Japan has no energy consumption standard for architecture.

Japan has some of the most stringent anti-fire or anti-earthquake standards for architecture in the world. And they’ve continually updated those standards as new situations have come up, like after the last earthquake or after the Great Hanshin Earthquake. So Japan does have a history of creating stringent standards when they see a need for it. But if you look at energy consumption, most people don’t realize that if you look at the amount of energy the country uses…I don’t know if you’ve ever seen this, but METI has an energy consumption data book that they produce every year, and they include this pie graph which breaks down energy usage in terms of the transportation sector, the industrial sector, and the private and public sectors. Those three pieces of the pie represent overall energy consumption, and the way that the pie is cut hides very obvious things. Buildings, including homes and commercial and non-commercial structures, are by far the largest consumers of energy in Japan, and most of the energy consumed by buildings is not by computers or refrigerators. It’s heating, cooling, ventilation, lighting and hot water production. Those tasks make up 70 percent of the energy consumed by buildings. So if the pie were cut in such a way that you isolated buildings from all three sectors, you would have a piece that would be bigger than any of the other three.

What that means in terms of safety standards is that the country has to pay all sorts of costs that are currently externalized. For instance, military preparedness in case there’s an oil shortage. Or global warming and climate change. And there are all sorts of costs associated with these things. On top of that the fact that Japan has to purchase most of its energy from overseas, more than 90 percent comes from imports, you could significantly reduce the amount of imported energy by having better building standards. It directly affects national security, economic growth, all kinds of issues. A lot of economists have shown that local consumption has economic payback. Every year, Nagano Prefecture alone spends ¥450 billion ($4.5 billion) for imported energy. If you promoted local energy production and consumption, the economic effect would be four to five times the amount of energy consumed, which means about ¥2 trillion in economic activity generated in Nagano Prefecture alone. And that would be huge in terms of economic growth, not to mention in terms of energy security issues. The fact that buildings aren’t being monitored for energy consumption is a huge issue for national security and safety, all kinds of things.

Also, a lot of people every year die from heat shock. They get out of a hot bath, walk into a cold room, and have a heart attack or stroke. So there’s a safety issue right there that can be addressed by more efficient energy usage. I think more people in Japan die from heat shock than they do from traffic accidents.

-How about cooling in a passive house?

The effectiveness of a passive house depends on location. Kaurizawa is a very cold place in the winter, and we only have about five days of over-30-degree weather in the summer. It’s pretty comfortable, and in the summertime the nights can be quite cool, so at night we open two small windows, one in the entranceway and one in the kitchen on the first floor. And we also have a skylight that can open via remote control. It’s above our stairwell. So warm air rises out of the skylight and pulls in cool air through the other open windows. We do that at night, and during the daytime I just close up all the windows because the house acts as a kind of thermos bottle. It keeps the temperature very stable throughout the day–in fact, for four days at a stretch. It’s hard to heat up or cool down the house, but once a desired temperature is reached it can stay that way for days. The change in temperature occurs so slowly internally that we don’t have to make dramatic adjustments. Like in my apartment in Tokyo, I have to turn the air conditioner on and off all the time. But here the changes are very slow. To give you an example, last winter we were out of the house for about ten days when the outside temperature would drop to minus 15 at night, and all we did was open the curtains to let the sunlight in. When we got back the indoor temperature was about 14 degrees, and that’s without any artificial heating. We had our first 0 degree day here the other day, but we still haven’t used any heating source, and it’s still around 20 degrees in the house. Our house is two stories and an attic, and the temperature variance between all the rooms is, at maximum, two or three degrees. Many people in this area have to keep their heat on all the time in the winter, even when they aren’t at home, because the pipes might freeze. So the heating bill for a house our size, which is about 160 square meters, is between ¥50,000 and ¥100,000 a month.

-Did you choose your plot of land with the passive house in mind?

You can build a passive house anywhere. But the level of efficiency will depend on location. In Karuizawa we need triple-glazed windows with 28 centimeters of insulation in the walls and 50 centimeters in the ceiling. That’s because of the annual temperature variations. If the house is built in Tokyo, you might be able to get away with double-glazed windows and less insulation. And if you were building one in Kyushu or Okinawa it would be far different. The design of the house, and the orientation, will depend on the location, too. That’s the problem with most factory built homes. They aren’t specific to location. They’re all the same.

-How many architects in Japan now are able to design passive houses?

An organization called Passive House Japan has trained several hundred architects in how to use the Passive House Planning Package, a tool that the Passive House Institute created to measure energy consumption in the architectural design process. There are quite a few people who can do that now. The problem is getting the house certified. The Passive House Institute is the official certification organ, and they’re based in Germany. In the U.S. and other countries, there are local certification authorities now, and they’re accelerating the process, but our house had to be certified in Germany so it took time. It’s tough in Japan to get it certified, but as far as getting a house built to the standards there are quite a few architects who can do that now.

-What’s the importance of being certified? Since the government doesn’t give you tax breaks or subsidies, is certification just for your own peace of mind?

As a third party certification process it says that your house was built properly. It’s quite common for builders to make claims that aren’t true, and with the certification process you can see what you’ve got. And as it turns out, the numbers we received with regard to energy savings have been almost spot on with what we’ve been getting in reality. And other passive house owners I’ve talked with have had similar experiences. I think it’s because the standard is so stringent that even if there is a significant variation it’s tiny in comparison with conventional houses because the numbers are so low to begin with.

-Is it difficult to find these architects in Japan?

You can go to the Passive House Japan website and contact their office and find an architect in your area. The key is finding one who really understands what it means. It isn’t rocket science. Any builder can do it, but the key is having it designed properly and then having the person who manages the building project understand that design and what it means. The architect who designed our house also controlled the construction process. So we could use any builder, and got three different builders in our area to give us quotes and our architect ran that process. One way we were able to eliminate conflicts, and the architect suggested this, is that we paid the architect a flat fee as opposed to a percentage of the construction cost, which is common in Japan. Our architect is Japanese, but she studied in Germany, where architects aren’t paid as a percentage of construction costs. They are paid on a per square meter basis. That eliminates conflicts of interest.

-How does the cost compare to a conventional house of comparable size?

In Japan, construction costs for a passive house is between 10 and 20 percent more than for a normal house of the same size. It’s mostly due to materials. Better windows and more insulation are the major factors. There is also some downward pressure on the cost, as well. Most houses in Japan have a lot of equipment that is not necessary in a passive house, like air conditioning units in each room. So it kind of balances out. Most of the cost is due to the fact that there are more materials. In Germany, where there is more competition, the cost is quite similar to a conventional building. On the other hand, in a country like Korea, where passive house development has been controlled by house builders, the difference in cost is like twice as much. They’re charging what they can. It’s not based on materials. They’re just taking advantage of people who want passive houses.

There’s also a misconception with regard to long-term costs. Something like 99 percent of homebuyers in Japan purchase their house with a long-term housing loan, usually with the Flat 35 plan, which is a very low cost loan. Most builders will tell you, “Yeah, sure, you can save on energy, but how many years is it going to take to pay off that additional construction cost?” Its an initial versus running cost argument, right? But, in fact, 99 percent of buyers don’t pay the initial cost. The bank pays it. That means 99 percent of people have zero initial cost, or close to zero, and then they have two sets of running costs. One is called home loan repayment, which is fixed for 35 years, they know what it’s going to be. And then they have another set of running costs called utilities, which are not fixed. And if history is our guide, they are going to increase significantly over the next 35 years.

The passive house takes your energy cost–your utilities costs–and moves it into insulation and better windows. That’s a direct replacement for energy consumption. So since you have no initial cost and two sets of running costs, one of those running costs is significantly reduced.

I’ve talked to several banks in our area and they’ve said they are actually considering new models for financing in terms of how much a person can afford for a house. Currently, they don’t factor in any utilities costs. But now they are considering saying, “If you can eliminate your utilities costs you can pay more for a house up front.” Things could change.

-It might mean potential home buyers become more aggressive about what they really want. Most people, we find, go to a builder or a developer and say, “Build me a house,” and wait for it to get built. In the end, they probably get a lot of things they don’t need and don’t get a lot of things they do need.

That’s a good point. In Germany, they have a national bank called the KFW, which acts in much the same way as the Housing Finance Corporation does in Japan. And they include in their loan criteria energy efficiency standards. So you have a $100,000 loan, but the loan is put into effect when you complete construction, which means you may have to take out a connecting loan. But if your house only consumes 50 percent of the energy set out in the KFW standards, it’s called a KFW 50, which means instead of paying off a $100,000 loan KFW will grant you $20,000 because you made a more efficient house. The remaining $80,000 still has to be paid off, of course, but the interest will be reduced. The actual house has to be checked. It’s not based on the drawings. That’s very different than the Japanese way.

The beauty of the passive house standard is that since the numbers are so carefully and clearly calculated you can avoid the housing salesman who waves his arms around and throws lots of data at you. You understand the exact number of kilowatt-hours your house is going to consume. Architects in Japan usually describe energy in terms of jules, which makes sense if you’re a physicist, but most people can’t relate to it. Or a BTU or whatever. But when you describe it in terms of kilowatt-hours it makes it way easier to understand. When you have a comprehensible, concrete number, you can compare more easily.

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20 comments

  1. Aaron · November 1, 2014

    Very interesting stuff. I’m renting in Tokyo but may be in the market for a house sometime in the near future, so I’ve followed your blog with great interest. Thanks for making this additional material available.

    Can I pick a nit? It’s “kilowatt-hours”. Kilowatts × hours, not kilowatts ÷ hours. http://en.wikipedia.org/wiki/Kilowatt_hour

    Like

  2. kevinmeyerson · November 3, 2014

    Thanks for publishing the full interview here!

    A quick correction:

    “I think more people in Japan die from heat shock than they do from fires.”

    This should say that more people die from heat shock than from traffic accidents in Japan.

    Like

  3. Karl · November 4, 2014

    Very interesting discussion. Boils down to the point that an education or common sense thinking based on material from junior high school textbooks is needed.
    However, Germany is not, has not been and would never be a good example rather than to serve as some sort of an anecdotal evidence. For starters, they have an access to cheaper central heating produced by natural gas from a pipe from Russia; the Germans love to keep their houses very cold; and they pay one of the most expensive electricity bills per household in Europe. The German government has started turning their backs on Energiewende policies on renewable energies and has increased its dependency on coal. Hardly, a great standard.
    However, the general point on the heat consumption here stands correct in my mind.

    A question though – how does a house in Karuizawa back up any argument on general saving when the interviewee claims that he would commute to Tokyo from there? I have not checked the prices but I would take a guess that a monthly commuter pass would cost close to 100,000 JPY.

    Like

  4. Nina · November 4, 2014

    Absolutely Loved Reading Your Article. Could you please be so kind and email me the name, website, and other info to get in touch with your Japanese Female Architect Lady who took care of your building! Thanks.

    Like

  5. kevinmeyerson · November 5, 2014

    Nina, our house was designed by Key Architects, based in Kamakura. They also managed the construction process. You can find them on google. Key Architects are extremely busy due to the huge interest in building ultra-efficient and comfortable Passivhaus buildings. I recommend you also contact Passive House Japan and as for introductions to architects in your area. PHJ is also online.

    Like

  6. kevinmeyerson · November 5, 2014

    Karl,

    Regarding your question: I commuted to Tokyo for several months before retiring. The monthly train pass was 126,000 yen per month which my company paid for at the time, so the financial expense was irrelevant to me personally. Also, since I travelled on regularly scheduled trains which run whether I rode them or not, the energy cost is negligible. In any event, I no longer commute to Tokyo.

    Regarding your thoughts on the German Energiewende: You seem to have your mind made up about the issue. I find it interesting that the German population seem to continue to strongly support the Energiewende (energy transformation), and that the cost of living in Germany continues to be lower, and quality of life higher than in Japan despite the massive increase of renewable energy and drop in consumption of fossil fuel and nuclear energy.

    Much of the price difference between energy bills in different countries is accounted for in direct taxation of energy. For example, Germany has very high taxes on electricity which encourages high rates of energy efficiency adoption in buildings. Other policies also reinforce energy efficiency. It is similar to high taxes on tobacco to discourage smoking, IMHO. Japan has far lower direct taxes on electricity (and tobacco FWIW).

    I also find it interesting that much of English language media commentary on the German Energiewende does not reflect what my friends tell me is actually happening in Germany.

    Regarding German homes being cold: I did not know that. When I travelled in Germany and visited many places, my wife and I did not notice any discomfort due to cold.

    On the other hand, many people, including myself, find many homes and buildings in Tokyo to be either too hot or too cold. This is mainly due to poor insulation in Japanese construction which makes huge amounts of artificial heating or cooling a necessity – that’s why most Japanese homes and other buildings have an AC and heater in every room.

    If you have time on your hands, look into the study of “Exergy” and its applications in architecture. It explains a lot on how people actually are more far more comfortable with fewer temperature variations in buildings. Exergy theory explains how people become more comfortable in lower temperatures if temperature variability is reduced. My wife and I both directly experienced this in our house.

    Also, the health consequences of Japan’s uncomfortable and inefficient buildings with massive internal climate variations are enormous. More than four times the number of people die each year from “Heat Shock” in Japan than from traffic accidents. In 2012, about 17,000 people died in Japan due to heat shock, and only about 4000 people died from traffic accidents. Heat shock is caused by the huge variations of temperature in homes and buildings. It causes strokes, heart attacks, and many other health problems besides death itself.

    My house has stable temperatures throughout and I know that I have provided my family with a healthy, safe, and extremely comfortable place to live. I confidently tell architects and builders I meet, “My house is far more comfortable than any house you have built.”

    Apologies that this post is so lengthy. I find that explaining how comfortable my Passivhaus is to someone who has not experienced a Passivhaus is similar to explaining the color orange to a blind person.

    Liked by 4 people

  7. Matsuki · November 7, 2014

    “Japan’s uncomfortable and inefficient buildings with massive internal climate variations are enormous.”

    ❤ That pretty much describes winter in Japan for most people. I'll never understand why tsukaisute homebuilding with a million band-aid "fixes" is still so popular here.

    Liked by 1 person

  8. kevinmeyerson · November 8, 2014

    Matsuki,

    In my humble opinion, the only way to fix Japan’s astonishingly broken building industry is to create mandatory energy efficiency standards in the building code. Japan already has a good track record for implementing strict fire and earthquake resistance building code. There is no reason why energy efficiency cannot be legally required.

    Liked by 1 person

    • Martin · November 9, 2014

      What’s frustrating is that building a house in Japan seems so expensive. Even a small concrete detached 2-bedroom house with cheap siding is $100,000-150,000. I’m sure they could make it much cheaper and still make a good profit but there are so many people with their fingers in the pie.

      Amazing that people are happy to pay that for a badly-designed and uncomfortable house. Then they’ll spend several million yen every 10-15 years renovating it and yet 35 years after it is built its value is 0. Argh!

      Like

  9. Donny T · November 12, 2014

    The insulation and sealing crack me up: A few years ago the big thing was avoiding “sick houses,” with formaldehyde and chemicals and various particles blamed for all kinds of problems. As a result of that silly panic, our house has ventilation holes in the walls of every room, and exhaust outlets in the ceilings, leading to a fan in the roof, controlled by a CO2 sensor, probably cancelling out the gains from the double-glazed windows. I guess every few years there’s a new fad, and it may be shifting to passive housing now.

    I’m surprised Mr. Meyerson was able to pull this off in Karuizawa: the building codes there are really byzantine and strict. Houses have to fit into the environment, and in practice I had thought that they forced that by requiring specific building techniques. When I inquired at one point about it, I was told that you needed to use a local architect, since an outsider would need to spend too much time learning and navigating the various rules and how they interrelate.

    Like

  10. kevinmeyerson · November 12, 2014

    Donny T,

    The sick house issue is a serious issue. There are still many building materials that are allowed in Japan that are illegal in other countries such as Germany. My architect studied in Germany and specified materials throughout the house that do not cause sick house problems.

    The building code in Karuizawa is not so complex as some may have you believe. Many builders and architects are working here and many move here from other locations. It is certainly not rocket science.

    FWIW, I would agree that architects who are not used to designing for various locations and environments should not try to design a house for Karuizawa. Or any other non-Tokyo-like environment for that matter.

    For example, most Tokyo architects do not have experience in designing buildings outside of Tokyo. The environment here is similar to Sapporo, temperature-wise, and there is high humidity in the summer.

    Architects who are trained to design Passivhaus buildings are forced to design specifically to site location, so building for Karuizawa was not a big issue.

    Also, we used local contractors via a local builder for the actual construction. Our architect managed the construction project.

    Like

    • Craig · February 7, 2015

      Kevin, thank you for sharing your experiences (here with at the excellent catforehead blog and elsewhere) relating to building and living in a passive house in Japan, it has been greatly beneficial.

      I am in the process of finalizing the plans for a passive house that I intend to build in Japan this year and have a lot of decisions to make. One such decision is regarding the ventilation system, I was wondering which make/model you went with for your ventilation system, how it has performed and knowing what now know about it whether you would have gone for a different system?

      Any information that you are able to provide would be greatly appreciated.

      Like

  11. Josh Petyt · November 13, 2014

    I was under the impression that passive houses usually include electronically controlled climate management systems that deal with humidity and heat exchange etc. You make no mention of this and only mention the windows being left open in summer.

    Like

    • Mark Brierley · December 13, 2014

      Josh Petyt, Part of the Passive Houses approach is mechanical ventilation with heat recovery. Air is pumped in and out at constant temperature 24 hours a day. If left to chance there may be too little air change, leading to excess loss of heat, or too little, leading to suffocation because of the high airtightness. Also because of the airtightness the ventilation is very effective. Ever tried sucking through a staw with holes in the sides? There is also heat exchange, so in the winter the heat in the expelled air warms up the cold incoming air, and in the summer the heat goes the other way, cooling down the incoming air in the heat of the day. In a conventional house, heat is delivered, usually at the press of a button, and to the profit of utility companies. On the other hand, a Passive House seeks to conserve the heat within the building to maintain temperatures. Junior high school physics, but we had a lot of trouble getting the concept through to the people building our house!
      One issue we have had with our ventilation system is with humidity. http://minuszeroeco.blogspot.jp/search/label/HVAC Compared to Europe, where our ventilation system is from, Japan has dry winters and humid summers, and the ventilation system exacerbates the humidity in both cases. It may make sense to have built in capability to humidify in winter, and de-humidify in summer, and I’d be interested to hear what strategies Kevin’s house uses, and how it performs over the next winters and summers.

      Like

      • Mark Brierley · December 13, 2014

        Sorry for typos:

        Air is pumped in and out at constant *speed* 24 hours a day.

        … there may be too *much* air change, leading to excess loss of heat,

        Like

  12. Mark Brierley · December 12, 2014

    Here’s a blog from another passive house in Matsumoto, Nagano prefecture: http://minuszeroeco.blogspot.jp/

    Interesting to hear about similar stories!

    Like

  13. Chris Anderson · March 24

    Hi Kevin,
    I would really like to know what make MVHR unit you used in your house and where you got it from…I am putting together my own house in Gunma and seems i need to import this equipment and use a power transformer..
    Great if you can point me in the right direction !!
    Chris A

    Like

    • Mark Brierley · April 4

      Hi Chris,

      You can get MVHR units in Japan, for example from Stiebel. There should be no need to import or use transformers. Stiebel’s site is here https://www.nihonstiebel.co.jp/ They may be able to supply to you direct, or recommend a fitter. We have been using a Stiebel for the past few years. The unit itself works OK, but there have been several issues with the installation, which you can read about here: http://minuszeroeco.blogspot.jp/search/label/MVHR

      Mark

      Like

  14. Steve Wisham · April 7

    Hi Kevin,

    Thank you for all the information about the Passive house. I’ve read in another article where you were interviewed about your place in Karuizawa. You mentioned a study done by Tokyo University where they put sensors in your home.

    Would you happen to know if they have published their findings?
    I am trying to convince some people about the benefits of the Passive House and they have asked for evidence.

    All the best,
    Steve

    PS. I live and work in the Tokyo area.

    Like

  15. Steve Wisham · April 8

    Hi Kevin,

    Thank you for all the information on the Passivehaus.

    You mentioned in another article that some people for Tokyo University did a study on your house in Karuizawa.
    Do you know if that data is available?

    I am trying to convince some people the benefits of the Passivehaus. They have asked for data.

    Thank you again,
    Steve

    Like

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