Cob: Building to code in Oregon

[Shannon C. Dealy]

On Fri, 20 Apr 2001, Robert B Krueger wrote:

[snip]
> partner, took a cob course with CCC last fall in coastal oregon.  We have
> land and want to build with cob but only get strange looks from our local
> county officials.  From what I have heard the only allowable cob
> dwellings have been non-load bearing, post and beam type with concrete
> foundations. These structures have used cob for the walls.  

This is not entirely true, the code does not specify what is allowed,
rather it specifies what structural, insulation, electrical and
plumbing requirements must be met (the general case) and what materials
and approaches are pre-approved.  Generally, if you can get an
architectural engineer to sign off on your design as meeting the code
requirements (much easier said than done), you should be able to build it.
Many areas also have owner-builder codes which will let you do a great
deal without the engineer.  In most areas so long as the plumbing,
electrical, (and sometimes thermal requirements) are met, the building
officials generally have a great deal of latitude and can let you build
almost anything reasonable, the problem is that it is rare that you can
find an official willing to go out on a limb in case someone tries to sue
over a building that fell on someone.

> I feel it is our duty to push the county officials to do their job, and
> so I thought I would ask the cob list folk if anyone knows of any cob
> structures which have been built with a building permit with the
> following: 1) a stone foundation, 2) were load bearing (ie. the cob walls
> were holding up the roof).  The county officials also say that cob has
> poor insulation and R-factor would not meet the building code despite the
> 2' thickness of these walls. 

I don't know of any structures that meet the above on a residential
building permit in Oregon, but Linda and Ianto's cob cottage (the one in
the Cob Cottage Company logo) located in Cottage Grove, Oregon was built
on a stone foundation as a load bearing cob under an agricultural permit
which has much easier requirements.  Of course anything done on an
agricultural permit you are not supposed to live in, but it might allow
you to build structures other than your house on the site.  Once another
structure has been built, you may be able to convince the local building
officials to cut you some slack after giving them a tour of your
"agricultural" building to see how sturdy it is.  As far as the insulation
requirements of the code, I don't see any way you can beat that using
straight cob, so you will probably need to wrap the residential structure
in insulation.

Basically, the above is my plan/approach for building in Benton county,
Oregon.  I have started off with an "accessory" building (under 120 square
feet foot print at the eaves) which does not require any permits (this is
the structure in my zero dollar house article), then I will apply for an
agricultural permit to build a cob greenhouse/office which will be built
using the same design techniques that I would like to use for the house
(rubble trench, stone foundation, cob walls wrapped in straw bales, metal
roof).  This will hopefully allow me to at least do part of the building
work on the site completely in accordance with my plans, and will give
them something to look at when I hit them with an application for a
residential structure building permit.  Of course if that isn't enough, I
can always go the more expensive route with the architectural engineer.


Shannon C. Dealy      |               DeaTech Research Inc.
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