[Cob] engineering/permitting

[claysandstraw]

> My county building inspectors said that it would not be a
>problem for me to >build a structure such as straw-bale/cob as
> long as I had an Engineer's seal. However, my friend is telling
> me that it can cost upwards of $10,000. Does anyone have any
> experiance with this our any helpful information?


Based on my experience engineering on cob is quite a simple affair.  When we
had our family house in NM permitted and checked by a structural engineer
($100 per hour - total of 4 hours.)  With roof loads including a living roof
and 5ft of snow (approx. 140lbs per square foot) he barely even blinked at
the cob/adobe walls and moved directly to calculating roof loads for our
round-wood timbers.
The one compromise was the concrete or wood bond beam that encircled the top
of the walls just below the rafters.  We chose concrete becuase I calculated
that the loss of the CO2 digesting power of ten trees (needed for a wood
bond beam) would be a much greater impact than the addition of Co2 to the
atmosphere for 2 yards of concrete. I must admit that the bond beam was a
bit of a pain but immediately and obviously strengthened the house,
especially the thin columns between the southern windows.

A note on price. Our house was "reviewed" by an engineer and "signed" by an
architect.  Signatures, which carry liability, are slightly more expensive.
We spent approx. $2000 in all on design and review for permitting.  We felt
it more important and less hassle to have everyone on our side up front
rather than having to defend the house at great cost and effort if we got
caught.

Kindra
claysandstraw.com