Straw-bale is a cool way to build a house

With the outdoor temperature near 87 degrees, Larry Biehn had ideal conditions to show off the virtues of straw-bale construction.

"What's the first thing you notice?" Biehn asked as he stepped through the back door into his Santa Fe-style house in northern Douglas County. "It's cool in here. We don't have air conditioning."

Walls made of straw-bale - actually rye-bale grown off Muller Lane - and concrete floors play the role of air conditioning and heating at the home of Larry and Susan Biehn.

The Biehns moved into their unfinished 2,700-square-foot house off Stephanie Way in March. They have yet to test the winter worthiness of their 18-inch thick straw-bale walls encased in two layers of concrete. The insulation quality is rated at R-52 compared with R-11 to R-19 insulation found in most traditional homes.

Constance Alexander, also living in the Stephanie Way area, has lived through four winters in her 900-square-foot straw-bale house. Even when she's away for days, the indoor temperatures has never dropped below 50 degrees.

Summer without air conditioning only once put the temperature at 80 degrees - and that was because Alexander forgot to open her windows before leaving that day. One day when the outdoor temperature was 84 degrees, Alexander's thermometer read 72 degrees.

"I think it's very comfortable," Alexander said. "My house is all electric. I have baseboard electric heat, which is the most expensive. And I have trees with a drip irrigation system. I use a lot of utilities and my electric bill is $47 a month."

Passive solar heating also brings down the bill. Huge south-facing windows at the Alexander and Biehn homes collect whatever winter heat the sun has to offer. The Biehns also use radiant heat - warm water piped through the floor.

The Biehns and Alexander live only blocks apart but took contrasting approaches to building their straw-bale homes.

Alexander went for the very simple, which is typically expected in straw-bale construction.

"I have a commitment to living lightly, using as few of the planet's resources as possible," Alexander said. "It's still something I don't do as well as I want to. It's a constant learning process."

The Biehns built a $350,000 upper-class home with huge rooms, high ceilings, windows everywhere and covered patios in front and out back. Logs called vigas span the ceiling in Santa Fe style.

"People are amazed: 'A straw-bale house that looks like this?'" Susan Biehn said. "They're used to the cubicle look. They were encouraged that you can do something other than a small cubicle."

Alternative construction materials have yet to catch on in Carson City. Building Official Phil Herrington knows of no homes in the city built with straw-bale, bamboo, tires, Rastra, mud or adobe, but he said the Carson City Building Department welcomes designs calling for alternatives to wood-frame.

"I'd like to have the public realize that we're open and progressive to innovative forms of construction," Herrington said.

In the last few years, many city and building officials across the country have warmed up to alternative construction materials. Why?

"Two words: David Eisenberg," said Thomas Hahn, an architecture professor at Arizona State University. "With much passion, he inserted himself in the building code process. Surprisingly, building officials have listened."

Eisenberg is co-director of the Development Center for Appropriate Technology which operates under the slogans "Building Sustainability into the Codes." He helped write the first load-bearing, straw-bale construction building code for Tucson and he did the troubleshooting on the steel and glass cover of Biosphere 2.

Even the Nevada Legislature adopted the spirit of alternative construction materials. A 1995 law requires local governing bodies to amend building codes to permit the use of materials that conserve natural resources.

"In our age, I'm not certain wood-stick is a conventional material," said Larry McPhail, Carson City's deputy building official. "Other means of construction have been used for thousands of years. We need to learn to utilize more non-depletable resources."

Mound House-based Ken Keyes builds homes with Rastra, blocks of recycled Styrofoam mixed with concrete. He is building his first Nevada Rastra house now in Fallon but he has taken alternate approaches to building some 300 homes in the Phoenix, Malibu, Redding and Calabasas areas of Arizona and California.

"I've dealt with a bunch of building departments," said Keyes, owner of Alternative Construction and Building Products. "I have no problem at all. They think it's great. People say watch out about this building department or that. I've never encountered any problems."

For two-thirds of the world's population, what we call alternative building materials are the common materials used to build homes. Only one-third of the world's population lives in buildings dealt with by the International Building Code, the primary building standards used in the U.S. and around the world.

Two billion people live in earthen structures like adobe, rammed earth or cob (not corn but a mix of clay soil, coarse sand, straw and water). Another two billion live in buildings made of other nonindustrial materials or scavenged materials like tar paper, corrugated metal, cardboard and shipping pallets.

"Do we have the resources and environmental capacity for the other four billion people to have houses like ours?" mused Bob Fowler, chief building official in Pasadena, in the January issue of Building Standards.

For the past five years, Washoe Valley resident Christy Tews has taught a one-day community service class on straw-bale construction at Truckee Meadows Community College in Reno. Her classes have led to five straw-bale homes now occupied in Northern Nevada and another four in the process of construction.

"I enjoy empowering people to do what they want to do," Tews said. "We're using renewable resources for walls and insulation systems. There is no compromise in living in a straw-built home."

The Biehns and Alexander dismiss the common perceptions that straw-bale homes are high maintenance.

"What maintenance?" Larry Biehn said. "That's why we do the stucco. There is no maintenance to it."

The Biehns used post-and-beam construction. Eighteen-inch bales of rye were stacked to make the walls. Chicken wire encases the rye, followed by a scratch coat of cement and then a brown coat of cement to give the wall a smooth texture.

A color coat of acrylic stucco is the final layer.

Doubters say straw bale is vulnerable to moisture or insects because stucco is prone to cracking. Alexander disputes such a notion.

"I think the concern for insects and rodents is exaggerated," Alexander said. "I've had no insect infestation, which I'm sure I'd know about. As far as I'm concerned, there shouldn't be any more maintenance than any other house."

Keyes in the past has built with straw-bale and other materials. His preferred alternative is the Styrofoam-concrete called Rastra. Keyes said a University of California study found Rastra 700 times stronger in an earthquake than wood-frame.

"It seems people really like the fire rating and far superior strength in seismic and wind ratings," Keyes said.

Rastra is lightweight and comes in 10-foot-long blocks that are cut to size. Walls are typically 10 inches thick and up to 14 inches.

The hollowed blocks are stacked vertically with steel rods inserted vertically and horizontally to provide structural integrity. The steel is grouted solid with concrete.

Rastra cuts utility bills by about 45 percent and can withstand fire for five hours, Keyes said.

Hahn, in Arizona, believes insulated concrete form systems like Rastra have a better chance to become a mainstream building material in coming decades that straw-bale.

"It's just a matter of time," said Hahn, also of the Desert Appropriate Living Institute. "A group of us are pointing out the fact that this is something greater than a single house. What's the best way to make use of building resources to take care of long-term human health and welfare? This is about global survival. In 20 years, I don't want to be calling it alternative any more."


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