Hi,
Looking to build a house within the next few years. Really like the idea of a Passive style house due to it’s ‘built to last’ ideology (not the 20/30 year standard box houses), and also being designed to not rely exclusively on several air-cons as the earth starts to boil.
However, Me and my wife went to see a Passive House builder last week and we’re quoted 5000万. Unfortunately this is not compatible with our average Kagoshima salary. Also due to being in Kagoshima, passive house builders are few and far between so I think this would be our only option if we wanted to build a passive house.
Has anyone found any alternatives to passive houses? Has any one used a bigger house maker and found techniques or materials that are more ‘passive style’?
Any advice would be appreciated, thanks.
5 comments
That’s very interesting.
I had never heard of a “passive house” per se.
Had to look up a few things. Here are a few additional resources, for anyone else interested as well:
[https://www.hisashi-kamakura.jp/](https://www.hisashi-kamakura.jp/)
[https://passivehouse-japan.org/](https://passivehouse-japan.org/)
I own a Toyota Home “Hiraya”, that was built in 2013. Modern, well insulated, all electric with solar panels. I had a solar battery installed as well, a couple years ago.
Toyota Home might be worth looking into if, as you say, a more small-scale architect isn’t available in your area.
[https://www.toyotahome.co.jp/](https://www.toyotahome.co.jp/)
ichijo has a category called “i-smart” which is close to passive house standard. Expect 15-20% higher price than standard house maker products. They do have a looong backlog it seems. Roughly 7 man per tsubo + 4M for fees and such
relevant link: https://www.ichijo.co.jp/lineup/i-smart/
The other big maker on this market is Sweden House, similar pricing to ichijo AFAIK. More european style of building if you want.
link: https://www.swedenhouse.co.jp/
As much as I like the idea too, I wouldn’t go with a passive house in an earthquake-prone area like Japan.
Not only is it not cost effective, it also might not be ecological due to the materials used – the house needs to be in use for a _long_ time before that pays off to the environment.
I’d suggest to go with the current standards and make sure to just have above average insulation (e.g. 3-layered windows) and, if you can, build the house so that you make use of sunshine as much as possible (big windows to the south, few small windows to the north). In addition, make sure to not have the standard ventilation built into every wall, but rather use a centralized or decentral ventilation system with a heat-exchanger. Then you don’t have to open the windows regulary, have less mold and save energy in both winter and summer. I’m sure you know about that, because it’s mandatory for any passive housing.
Also, make sure to get a good AC. ACs vary a lot in terms of efficiency. High-end ACs use ~33% less energy compared to average ones. It pays off in the long term.
I think with that you can easily come very close to a passive house without paying the massive costs.
Another terminology you should look into is ZEH (Zero Emission House, pronounched like zech). I think if you install a bunch of solar panels that cover your yearly energy needs that’s good enough to be qualified as ZEH but not sure.
Ichijo and Sweden are good start as others said. But yeah, they are expensive.
This is a topic that comes up here with some regularity but the Reddit search is so bad that it’s understandable that you might not have found the past discussions. [This Google search will bring them up](https://www.google.co.jp/search?q=passive+house+site%3Areddit.com%2Fr%2Fjapanlife).
Personally, considering that you’re in a rural area where land is relatively cheap, I would look into buying an older house and then upgrading it. Get enough land that you can set up a poor-man’s geothermal solution for cooling, they can be built for a few hundred thousand yen, you only need to bury the coolant pipes 2m or 3m deep to get all the cooling you want in the summer, but you need space to make it happen. 3000m^2 to 4000m^2 of land, ideally. You can cool your entire house using only 100W or so of power.