[Cob] Insulative values

[Christopher Reinhart]

from Damon:

 BUT, I have read about 100% cob homes being quite comfortable year round
> in Canada. You're wanting cob to be something it's not.


I have read this, too, but have no first hand experience. I think a related
story about Enertia homes (a double envelope home which uses lots of
thermal mass) illustrates something that I think is probably true of cob
homes, as well. In regards to occupants of these homes, "they were willing
to tolerate less comfortable conditions than the average homeowner." The
whole story is here:

http://www.buildinggreen.com/auth/article.cfm/2007/7/10/Enertia-Double-Envelope-Home-Still-Has-Problems/

To me, the issue is in what ways can cob be BEST used in a home. While a
solid cob wall home may work well, even in extreme conditions, if a
bale-cob wall works better, then that's what I would pick (assuming straw
bales are available). Cob is a fabulous material, but, like all materials,
it has limitations. Figuring out how to celebrate its strengths and buffer
its weaknesses is where design comes in.


Damon's comment to Sky:

>  If you are sold on the insulation factor means everything and thermal
> mass means nothing scenario (which it sounds like you are) then I do not
> see room for cob in your life.
>

I disagree. I think that questioning is positive, and just because Sky is
asking questions doesn't mean that cob cannot find a place in Sky's
buildings. An inquisitive mind that challenges the status quo (even if it's
the natural building status quo) is healthy for all of us. Blind faith is a
poor mindset and is not empowering to the individual. Cob is highly
empowering to the individual, but it loses some of its magic when rigid
adherents are unwilling to consider hybrid construction systems in which
cob only plays a part. Also, Sky is absolutely right that much more energy
is used to operate a building during its lifetime than is embodied in its
materials.

There is a graph from a study of of embodied energy of materials compared
to lifetime energy use of buildings about halfway down the page at this
link (it's the one by Cole and Kernan):

http://ryanenschede.com/writing/the-argument-for-conservation/

Keep questioning Sky! And ask those questions in the physical world by
building them and experiencing them for yourself.

-Chris Reinhart