[Cob] Insulative values: Frank, Mike, Janet, Sky, Chris, others?

[Sky Orndoff]

First, congratulations Melissa and Tys for finishing your place.  I'm sure it's gorgeous.  

Second, dear  Mike, Frank, Chris, me, Janet, and everyone: 

Thank you all for discussing this topic.  I don't think until recently insulation and airflow have been well covered here, and we're the people who need to be talking about it.  I believe that some of the most environmentally aware and friendly building styles are exactly the kinds being advertised by our friend Frank.  They're not "natural," but they are comfortable and save energy, and over a house's lifetime, energy savings adds up--much more so than embodied energy in materials.  

A mis-designed house, even a small one, will burn a lot of fuel to heat itself, and if its a woodstove, will burn
 a lot more wood than it would take to build a larsen truss house.  You could easily burn that much wood in only one winter!  The tiny houses typically built with cob are a great niche for those of us kooky and wonderful enough to dream and build and live in them.  For the rest of affluent North America, what Frank is proposing is exactly the right path.  And even us dreamers should improve our cob's thermal performance learning from those techniques.  You've done your homework, Janet, and your house is well designed on the right track, but many of us are still worried you'll be cold.

For the record, Frank, I was assuming a 2x4 or 2x6 stud wall with fiberglass batts, installed averagely, with a mediocre vapor barrier.  Here they even claim 2x6 stud framing to be "environmentally friendly" because of their "excellent" r-19 insulation (which discounds thermal bridgeing of studs, plates, and windows.  I don't think you're getting your respectible r-30 to 60 walls with batts.    What is the insulation you're using, and how thick are the walls? Tell us more!

A full 60 percent of landfill mass in the US and Canada is paper waste, which could be converted into cellulose wall and ceiling insulation at a very low environmental and monetary cost (we'd be pulling insulation from the waste stream and all we have to do is grind it up and add fire retardants) and we could be doing nice thick insulated walls in all the buildings we intend to heat.  I am sold on the Larsen truss technique Frank is talking about.  In fact, I'm building one right now and I think it's a great method.

Needing less building acclimatization is one of the easiest ways we can decrease fossil fuel use.  The best way to avoid heating
 and cooling buildings in most of our country's climates is primarily by insulation, and only secondarily through thermal mass.  I believe that due to high thermal retention and therefore low heating costs, the highly-insulated, low-infiltration rate houses Frank is talking about are probably the best way to go for most people.  Especially when combined with those impressively low infiltration rates.  If we in natural building can learn from pioneers in conventional building (r-60 walls and 100 attic with .5 ach under 50 pascals--that's fantastic!) we will end up with a much happier population and planet, with fewer of our dollars needlessly burning fuels just to heat or the atmosphere.  Frank, please tell us more about this technique you're advocating!

Thanks all,

Sky