This NY Times article about "passive houses" is very intriguing, especially considering all the crazy ice storms and power outages lately all over.

Growing in popularity in Germany and Scandinavia, "passive homes" are heavily insulated, tightly sealed homes which don't require active heating, even in the coldest German winters. Passive heating from the sun or the household appliances or even body heat will be enough to keep the house warm.

One trick is ventilation. But changing the air usually means loss of heat, but the use of a heat exchanger can reclaim that heat when drawing in fresh, cold air from outside.

Interesting article.

I`m hoping to one day go Geo-Thermal For now it's just wood stove, with no AC. Pretty close to a 'passive house' ... hahaha

We looked at doing a "passive home" for a customer. Using Energy Star HERS system their budget would allow for about a 4200 Sq. Ft. structure. The plan they had designed for a Passive House had to be reduced to less than 1800 Sq. Ft. to stay in the same budget, AND it was suggested they have an air conditioning system to cope with Texas heat/humidity.

It may be a relatively novel concept in the US but in Europe it has been around for a while. Those passive houses really work. If you do the maths right and know how to improvise, building a passive house is actually much cheaper than conventional construction. I know a family who built their own passive home almost entirely out of natural, locally available materials (mostly wood and mud) for very little $ and it's a pretty comfortable place to live. A friend of mine has started a similar project. We'll see how it turns out.

Don't get me wrong, I am all for it. It is just getting the cost down.

Did someone say strawbale?

We'll likely build our dream home as some type of non-traditional, a few years down the road. We've looked at straw-bale and toured the Earthships in New Mexico. Those are very cool, but for something close that still looks conventional, I've been intrigued by the double-shell Enertia homes.

www.enertia.com

My best friend's Father (a Fermi lab scientist) converted an old farm house to a passive solar home over 30 years ago. After the project not much of the farm house was left, but the end result was really impressive.

The ventilation issue was the limiting factor in some 1980's experimentation in such housing in upstate NY. Houses were built to specs that were a little too air-tight, resulting in near lethal accumulation of carbon oxides, humidity/condensation issues, and in having the the kitchen window blow out if the front door was closed too emphatically.

My ancestors in Ireland used building style that involved a two-story dwelling with the livestock-cows, goats, pigs- housed in the first story, and the folks housed in the second, taking advantage of the livestock-generated convective warmth, and providing a sort of ground floor pantry of very fresh meat products. This could be adapted to urban-friendly livestock-guinea pigs,rabbits, pigeons, cats and dogs- with a suitable change in recipes. This arrangement encourages copious ventilation-the folks upstairs really WANT to have a window or two open, even in the worst weather, but occasionally the stench and squalor became unbearable...to the pigs.

Had the opportunity to stay in a strawbale house a couple of years ago. This was down near San Diego, CA over the 4th of July holiday.

It was very impressive. Outside temps over 100 degrees F, indoors, highs in the 70's. So long as we stayed indoors, it was great.

The insulation was very good, the bales were covered with an adobe like substance.

I could easily see using this sort of construction process on a house located in the Southwest U.S. and if things work out in the future, will probably do so when I move to New Mexico as I hope to.

The problems I see with things like alternative building processes, energy sources, etc. are that people seem to think that a "one size fits all" method will work when it clearly won't. A house that will keep you cool in the Southwest U.S. might not and probably won't work to keep you warm in a Northwest winter but there are always alternatives that will work, usually better than the standard wood frame, drywall interior houses that have become so prevalent. Same thing with solar power, will it work for everyone, everywhere? No, but when it's used properly, in conjunction with other sources, it lowers our dependence on things like coal fired electric generating plants. Same thing with my cars that run on veggie oil, they're not a panacea or a total solution to using gasoline, they're a tool, a small part of the process.

JohnE

I agree that one building method or material or technology is unlikely going to be the absolute best way for all situations. But the extreme thermal efficiency that is possible in these (at least in Germany) "normal" houses is really astounding. Considering how much power one of today's flat screen TV's consume, much of it going into heat. Imagine trapping that heat and being able to actually provide a comfortable living environment during the winter with that heat. Wow.

It would also be nice not to have to live in a house that looks like the home of a hobbit from Lord of the Rings, or Obi Wan Kenobi's adobe-like home from Star Wars to get that kind of thermal efficiency.

Strawbale house in in fire prone California, that sounds like a recipe for one hell of a big signal fire.

Strawbale houses are more fire resistant than many stick houses. The straw in a typical bale is packed very tight which reduces oxygen access. The surface covering is usually nonflammable (usually an adobe-like). Though I won't say that it would survive a wild fire, I would rather be in a strawbale house than a stick house in such a situation.

I don't know 'bout houses, but I have seen large stacks of baled hay spontaneously combust. Very hard for the fireguys to put out. Seems to me that if the sides of the bales were not sealed VERY well, you could be making a nice home for rodents, they love hay bales...

Need to correct something, I wrote above that "The problems I see with things like alternative building processes, energy sources, etc.", what I should have written and what I meant was the problem people have with alternative building methods and processes..."it's a people problem, not a construction problem. There's nothing wrong at all with alternatives. Quite the contrary in fact.

As for strawbales in fire, the bales are covered with adobe/concrete as I mentioned, the house I stayed in specifically is near Julian, CA, scene of a tragic fire a few years ago, the house not only survived, it came thru virtually unscathed. The house is also interesting in it's shape, it's round with a timber frame. A dome shape if you will, very efficient in it's use of space, relatively inexpensive to build and dead easy to maintain.

Doesn't look like a hobbit house...;^)


JohnE

I have heard/read that homes using tires for exterior walls work pretty well too...

Do a little research on it. There are structures here in Nebraska that are over 100 years old, and yes there are rodents here.

As far as longevity goes, aren't large sections of the Great Wall made from soil with rolls of grass acting as a kind of re-bar? Believe I saw that on Discovery or NatGeo.

HAY has been known to spontaneously combust when the moisture content is more than 22%, and the large bales shouldn't be more than 16-18% moisture.

STRAW is usually pretty dry by the time the grain is harvested, and bales for houses usually have a moisture content of about 15% or less, and you must make the effort to keep it that way until it is sealed.

Tests involving baled straw and propane torches have produced singed bales, but none of them would actually ignite.

A couple of victims of the Malibu wildfire (1990?) returned to their home to find everything was ashes except the experimental straw-bale bench they had made.

Straw bale walls usually sit on shallow concrete troughs and are completely covered with the media of choice, often concrete on the outside and lime plaster on the inside. Building this kind of home with gaps in it is just begging for trouble. If a rodent is sealed inside the wall, it is called a 'Rodent Tomb'.

If I could afford to drop-kick this mobile off a high cliff, passive solar/straw-bale is the way I would go.

Sue

My dream house, meant for Southern AZ, is rammed earth, thick walls, adobe style. Critter proof, mostly.

We owned a wood frame with wood shingle clerestory style in New Mexico, during the winter the lower sun shone through the high south facing windows, adding heat, and during the summer, the sun was higher, thus, didn't shine in and kept it cooler.

It was so warm in the back rooms (where the high windows were) that we never had to light our woodburner in the master bedroom, even during a power outage with no other source of heat. And during the summer, the windows could be opened for great cross ventilation.

Great design, except in a monsoon situation, since the windows leaked! I sold the house and moved to CA before ever addressing fully, although we did caulk them up temporarily.

We had a neighbor with strawbale, loved, it, affordable and durable.

Good points on hay vs straw Susan. It's definitely a viable building method, hope to be using it myself before too long.

JohnE

The Mongols have been living this way for thousands of years. Their shelters (yurts) only maintain a fire for cooking and entertaining. Their sleeping quarters are a small tent of yak skin with the fur inside. It is tightly closed and heated by body heat. And this is in Mongolian winter (close neighbor to Siberia).

If I didn't have so many damned cats, I would try a yurt. I think they could bust out of that pretty easily though.

"If I didn't have so many damned cats, I would try a yurt. I think they could bust out of that pretty easily though."

I spent a weekend in one of the insulated yurts in an Oregon campground. Pretty solid construction, small electric heater, couldn't see any gaps, no drafts, framed door and windows, solid door.

If you happen to find yourself along the Oregon coast, find one of the State parks that has them for rent. Quite nice, actually, even in a cold, windy, rainy October.

Pacific Yurts

Sue

There's a lot to be said for traditional construction methods. People all over the world have already devised excellent solutions during the course of history. Case in point, anyone who's ever travelled in the Sahara desert is probably well aware of just how cooler and more comfortable the older mud brick buildings are opposed to the more "modern" concrete and brick houses that are now becoming much more common.

It doesn't take too much effort to adapt these solutions to our particular needs and modern technology. But trying too hard to come up with something "new" too often leads to reinventing the wheel, I'm afraid. Also, few people building their own passive house nowadays understand their environment well enough to devise an optimal construction. The vast majority of us simply have not lived with nature as closely as our ancestors and don't know the environment well enough.

I've seen a guy who built a house almost entirely out of clay, straw and a little wood. It might have been just perfect for an arid climate but he built it in a fairly cold area with plenty of rainfall. The insulation is still excellent but the rain and snow degrade the mud walls to the point where they require serious repair at least once per year. Not that the repair itself is costly but it needs to be much more frequent than most people with a reasonably modern lifestyle could tolerate IMHO. On the other hand, had the gentleman in question only looked a bit closer at the traditional houses in the area (mostly wood), he might well have selected a different design much more appropriate for his region.

I have lived two different cold drafty old farm houses.
Both were well over a hundred years old. Both had flower beds around them.
Both had full basements.
I used to pile straw about a foot deep over the flower beds and up against the house. More to protect the foundation walls from getting pushed in by frost than to save the roses. Then when it snowed the straw would be covered by snow up to three feet most winters
In the spring I used to rototill the half rotted straw into my garden.

I only had wood heat in those houses and as I said, they were drafty, almost unheatable.
If you left a jug of milk on the table overnight it would have ice in it in the morning.
Yet even if I was away for a month the basements never froze, I never had frozen pipes, and if I pulled back the snow and straw the flower beds would have been diggable in the coldest months of the year.
Straw and snow are great insulators and the ground in most places around the world is about 41 degrees fahrenheit.

I also had fewer mice in the house when I did this, I guess they preferred the straw to nest in than the uninsulated walls. I also had fewer weeds and more fishing worms in the flower beds for some reason.

I guess geothermal energy does not always need to be highly technical or pricey.

Actually, images of Luke Skywalker's home in Star Wars come to mind when you mentioned that adobe-covered dome house. Y'know, the one belonging to Uncle Owen and Aunt Beru.

Yeah, but you know how they ended up...