SOLAR AND STRAW

SOUTHERN EXPOSURE: Izaak Edvalson describes details about the straw bale-insulated and solar-powered house he is working on at Buchanan Lane near Island City. (The Observer/CHRIS BAXTER).

- Bill Rautenstrauch

- The Observer

A solar-heated, straw bale house, taking little from the environment but giving back much comfort, has long been a dream of Mary McCracken's.

But it took a meeting of the minds between McCracken, a local activist, and a well-traveled, idealistic — and highly skilled — carpenter named Izaak Edvalson to make it a reality.

"I had ideas abut materials and function in terms of sustainability, but not much more. Izaak was able to run with it," McCracken said recently about her new house going up on Buchanan Lane near Island City.

Edvalson, a teacher and Peace Corps volunteer with a construction background, is heading up the building of the 1,400-square-foot, two-bedroom affair.

He is working with general contractor RMC Quality Construction, owned by Roger Yeates and Matt Benintendi.

While giving a tour of the construction site recently, Edvalson said things he saw during a Peace Corps tour in Africa sparked his interest in straw bale technology.

"You see a lot of straw bale construction over there. That's where I got interested in using natural materials and solar power," he said.

The heart and soul of Edvalson's current project — McCracken's house — is a huge south-facing wall graced with just the right number of windows.

"Homes people built in the 1970s and 1980s had too many windows, but by now it's been worked down to a formula," said Edvalson.

The windows are set so they catch the sunlight in the winter and are shaded in the summer. Sunlight will be the home's main heat source.

"We figured it out with good old trigonometry," said Edvalson. "There's an overhang for shade during those times of year when the sun

is high. Then in the winter the sunlight slants in beneath the overhang."

An awning equipped with solar panels spans the south wall as well. The panels, glass over copper tubing, heat an anti-freeze-like fluid and produce a back-up source of heat.

The fluid flows through pipes to a heat exchanger kept in an equipment room in the garage.

It is converted to hot water, which, depending on need, flows to coils that are embedded in the house's clay flooring. The floor provides radiant heat on demand.

Solar power not only heats the house, but also provides electricity.

Photovoltaic panels located nearby will produce direct current, which in turn will be converted to alternating current for home consumption.

A special meter provided by Oregon Trail Electric Co-Op, the local electrical utility, will measure how much electricity the house takes from the power grid, and how much it puts back.

"The savings on electricity aren't big. They come over time, because there's so much up-front costs for the photovoltaic panels. But I think for Mary, this is less about the savings than it is about environment and ethics," Edvalson said.

Straw bales, good for holding the heat in, will be used for all the walls except for the one on the south, Edvalson said.

Straw bale houses date back a long way, even to pre-historic times.

In the United States, straw bale houses were especially prevalent on the midwestern plains during the 19th century.

Pioneers of the Great Plains used straw bales because they were cheap, plentiful where wood and other suitable building materials were not, and excellent insulation because of their thickness.

Edvalson likes them for those reasons, and more.

"You can bend and shape and stack them any way you want. They're real easy to work with," he said.

In straw bale construction, the bales are stacked in rows, on a raised foundation that includes a moisture barrier.

There are several ways of tying the bales together — wood and wire mesh and rebar have been used — but in McCracken's house the bales will be tied together and supported with bamboo.

Once the bales are up, the walls will be plastered with a clay substance, and the finished product will look like stucco.

Edvalson said Union County potter David Waln is involved with the project, experimenting with locally available mud to find which is the best for the wall covering.

Edvalson, who has attended workshops and seminars on straw bale houses and helped to build one in Colorado, said the walls are amazingly strong and durable.

"There are 100-year-old straw bale houses still standing in Nebraska," he said.