K. Shawn Edgar
December 5, 2008
Take a look around. Drive under the speed limit in a few residential neighborhoods in the Tualatin Valley. You will see that most houses, condominiums and apartment complexes are made of timber and other forest products. At this point you might wonder aloud, “Why is everything made from wood?”
Well, here’s an idea as to why, and some historical background to mull over.
Because these materials are considered standard by today’s housing industry, timber seems to be the only option for those developers wanting to build entire neighborhoods at one fell swoop. The infrastructure for using timber and manufactured wood products has been in place for many decades, creating a cycle that not only promotes its own growth through squeezing out and quickly forgetting the alternatives, but also by offering incentives like wholesale discounts to developers. This helps to re-enforce the compulsion to develop larger and larger areas.
Framing crews can use previously manufactured materials to frame several houses concurrently. So the convenience and the renewable supply of materials provided by well-managed forestlands have embedded this practice to the degree that makes every other part of the development process dependent on the use and sale of forest products.
It is the industry’s codependency on finding more ways of increasing profit and lowering cost that has lead to building entire neighborhoods for the sake of ease and monetary benefit to the developers and their myriad suppliers without consideration for the area, its needs and resources, or the community that already exist there.
Building materials have not always been so limited, and timber has not always been the dominate choice. Prior to the completion of the transcontinental railroad system in the late 1860s, which helped unify a nation-wide network of transportation, choice of materials for homebuilding varied regionally. In the Midwest of North America, where grasslands flourished, the people made use of sod — a grass-covered topsoil held together by matted roots, which could be cut into blocks and used as bricks.
In hotter, drier climates of the Southwest, American Indians and Spanish immigrants used clay-heavy soil mixed with sand, straw, or sometimes animal dung, and water to form adobe bricks. Simple shelters of sod, adobe and cob sustained the pioneers of the same period on their trek to the Northwest. In the constant struggle to survive, dwellings made from earth keep them warm in the winter and cool in the summer because soil is a natural insulator. These building materials — like timber today — were the standard in much of the west until the mid-eighteen hundreds.
Traditional building materials like these are now considered “alternative” and have been shunned by the mainstream. Their use, however, in what has recently become a revival of vernacular architecture — buildings constructed individually from indigenous resources to fulfil local needs — is key to moving the housing industry toward a more regionally based and environmentally aware mode.
To that end, individuals like Carrie Davis are playing a greater role in defining what houses and housing developments should be. Davis, a cob house enthusiast, is planning what many today would consider unthinkable. A house made of mud. What she calls, “her mud hut.” This is in direct contrast to the design most would picture when planning their dream home. Davis, however, is thinking and acting outside the prefab box and shunning the industry’s predefined floor plans.
“The cool thing about cob is it’s a load-bearing wall. It doesn’t need to be framed or re-enforced,” said Davis, a Beaverton resident, “because it is made out of sand, clay and straw. The straw gives it greater tensile strength throughout the mass of the cob.”
She then added, after a moment of thought: “The nice thing about straw and the way it mixes in is that you have re-enforcement in all directions, unlike with rebar.”
Cob and adobe tend to be more resistant to seismic events because of the nonuniform nature of the straw, whereas rebar grids placed in concrete only add support to the mass on one plane, and timber structures need to be specially re-enforced by bolting the wood frame to the concrete foundation.
So why don’t developers construct their at-one-fell-swoop neighborhoods using cob, adobe or sod? Davis believes the building industry is too tied into the current mood of quick and easy turnaround to consider the challenges and benefits of working with the more traditional materials and methods.
“There’s so much immediate profit benefit from the way it’s done now. The industry is completely tied in to the overall system or structure of the way materials are made and sold,” she said. “It allows them to build more cheaply and make more money, but they have to continue to do things a certain way. So to change what they do they’d have to change how they get their materials and who they get them from.”
The answer to this conflict between what is best for the industry of homebuilding and what’s best for the people who want well-made homes is the progressive action of individual citizens like Davis to redirect common practices toward vernacular architecture. If neighborhoods are planned and executed by locals with the interests of the community as their lodestar and using locally available materials, then the houses and other buildings will reflect what is needed in each area, she suggests.
Davis looks to the past to inform our future, “With greater consideration of our situation and for the availability of traditional materials, we can be more effective and efficient builders. We can build structures to last without totally destroying the area around us. I think people who use alternative practices have conscientiously made the decision to sacrifice time for the right materials and methods. This might be more expensive in the beginning but we gain stronger, better-made houses and neighborhoods in the long run.”