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More people are finding out the advantages of living in a straw bale home.
Four years ago, Beth Hoffmann built the first and what is still the only straw bale home in the city of Tempe. Hoffmann, a retired teacher and staunch environmental advocate, liked the idea of using bales of straw for her home’s walls and saving trees in the process.
A straw bale home looks like a typical adobe home except for one thing—the thickness of the exterior walls. The walls are about two feet wide, the thickness of the bales themselves. Hoffmann says it took about 160 bales to build her single-story, 1,200-square-foot home. She bought her building-quality straw bales from a supplier northwest of Phoenix for $5 each, including delivery.
Then this petite former Iowa farm girl had to figure out how she was going to stack them. Bales weigh close to 80 pounds each and must be stacked to a height of almost nine feet.
So Hoffmann took a small display of her dream home, with a graham cracker crust and wheat biscuit walls, to an organic produce market in Tempe where she works every Saturday. She propped up a sign that read, “Anyone who wants to help build a straw bale house, sign here.”
Thirty-three people signed up, and 30 showed up a few weeks later to build her home made of straw. The home was built on vacant land near West 13th Street and Roosevelt in Tempe. With that many hands, it took only half a day to stack the bales. “We had a party,” Hoffmann says.
Beth Hoffman stands at the entrance to her straw bale home
After the bales were in place, they were secured by driving two pieces of rebar through each. While straw bale experts would recommend wrapping chicken wire around the bales and then using stucco or other plaster to seal the walls, Hoffmann instead chose to spray the surface of the bales with several coats of “mud water” followed by a mud plaster mixed with lime. The mud water allowed the bales to accept the plaster, and the lime stabilized the solution, she says.
Her son, who has a degree from Arizona State University in solar architecture, designed the home so Hoffmann can minimize her use of gas and electricity. A row of south-facing windows below a roof with a generous overhang allow light from the low-angled winter sun to enter, striking the cement floors. The floors then act as a heat sink, absorbing the radiant energy and stabilizing the room temperature during the winter months. The cement floors are embedded with water-filled coils hooked up to a separate water tank should she need radiant heat during a cold spell. “The house stays so warm during the cold months that I haven’t had many chances to use the heated floors though,” she said.
And should she decide to collect rainwater from the roof, it is made of galvanized steel so it won’t contaminate the water.
Building the house seemed easy compared with what it took to convince city officials that building it was a good idea in the first place.
Hoffmann says it took 11 months to get a building permit from Tempe. After the city finally approved the building plans and a contractor had prepared the footing, she was told that it had to be redone because it sits on landfill and may not be solid enough. That cost $2,000. Then she had to pay a city inspector to come out on a Saturday to perform the final inspection.
The project was so unusual that city inspectors visited every few days during construction.
But Hoffmann says she wasn’t motivated just by getting a unique place to live.
“I’m a fiend when it comes to our environment. I’m so concerned about our trees” and how many trees are used to build homes, she says.
* Enhance and protect biodiversity and ecosystems
* Improve air and water quality
* Reduce waste streams
* Conserve and restore natural resources
* Reduce operating costs
* Create, expand, and shape markets for green product and services
* Improve occupant productivity
* Optimize life-cycle economic performance !
* Enhance occupant comfort and health
* Heighten aesthetic qualities
* Minimize strain on local infrastructure
Courtesy of Environmental Protection Agency
Steve Kemble is surprised more people don’t build their homes out of straw.
An engineer by training and owner/operator of Sustainable Systems Support in Tucson, Kemble says that straw bale homes, if constructed properly, provide the best insulation and heat retention of all buildings.
Standard modern-day homes have an R value (the ability to retain heat) of 20. A well-constructed straw bale home can have an R value twice that—as high as 50, some straw builders say. In addition, the buildings are aesthetically pleasing and almost soundproof, Kemble says.
Hoffmann says that when a plane flies overhead en route to and from the Phoenix airport only a few miles away, she does not hear it. Nor can she hear the traffic just outside her home.
Kemble operates a mail-order business that provides expertise in straw bale building. He also consults and conducts workshops on straw bale homes and other “green buildings”— structures that use alternative energy sources, such as solar power or wind power, and those built with materials other than wood and other natural resources.
Considered an expert in straw bale building, Kemble has been called on to write the straw bale building codes for some regions. “I’ve rewritten the code for Cochise County for straw bale, but haven’t been able to implement it,” he says.
The county has adopted Kemble’s revision as a “guideline” but not a rule because one municipality, Sierra Vista, refused to go along, he says.
People resist because they think straw bale buildings will surely rot, get infested with mice or burn easily, Kemble says. But those things won’t happen if the bales are selected, stored and prepared properly.
Builders do have to be careful about the quality of the straw, Kemble says. “The quality of bales varies from year to year, from farmer to farmer.” Moisture can be a problem. The bales must have less than 20 percent moisture, but even drier is better.
Kemble has his own straw bale home in Bisbee, Arizona. His was the first one built by southeast Arizona’s Canelo Project, a non-profit organization founded in 1989 by Bill and Athena Steen. Housed on the couple’s 40-acre home site at the foothills of the Huachuca Mountains about 70 miles southeast of Tucson, the project aims to bring “people, culture, and nature together” in the process of building, Athena Steen says.
The Steens have written several books on straw bale building, including The Straw Bale House and The Beauty of Straw Bale Homes. In addition, they run workshops from their home that teach students how to build with natural materials, such as cob, clay straw and straw bales.
30 people helped to build Beth Hoffman's straw bale home.
A visit to the Canelo Project
On a recent Saturday, would-be straw bale homebuilders showed up for a tour of the Steen’s project dressed in sensible shoes and L.L. Bean-style outerwear. The air smelled of rain and wet straw. Bill was away at a book signing to promote one of the couple’s books, leaving Athena and their three sons as hosts for the day. They were joined by their two adult dogs and a new litter of seven puppies.
Athena led the fascinated group through a mix of just-started, half-finished and completed green buildings, explaining how each was built.
Occasionally an “intern” or “disillusioned architect” comes to stay for weeks and even months, Athena says with a chuckle as she backs up against the cozy, multicolored straw bale hut referred to as The Cottage. The intern usually takes up residence in this small structure, which looks like a college student’s dream. Only a few hundred square feet in size, it’s a multicolored gem that sparkles purple and peach when the sun streams in from the generous front panes of glass. A pitched, bamboo-lined ceiling canopies the small loft and cramped single room below. On one wall is a “truth window,” a cutout in the wall that’s framed like a picture and shows the “truth” of the wall composition. Outside, a generous roof overhang encircles the entire building.
Athena tells the group that the roof overhang on a straw bale home needs to be more generous than on a standard home. The goal is to protect the walls from a natural enemy—water.
Here are resources that will help.
U.S. Department of Housing and Urban Development has a guide to energy-efficient design. 202.708.1112
Smart Communities Network specializes in energy efficiency and renewable energy.
The Green Building Program in Scottsdale encourages construction that is “healthy, resource- and energy-efficient.”
Build it With Bales: A Step-By-Step Guide to Straw-Bale Construction (1995) by Steve MacDonald and Matts Myhrman
The Straw Bale House (1996) by Athena Steen, Bill Steen and David Bainbridge
The Beauty of Straw Bales Homes (2000) by Athena and Bill Steen
The Last Straw is a quarterly journal about straw bale building worldwide. 402.483.5135
Straw Bale Construction Association, Santa Fe, N. Mex.
Information about straw bale architects, designers, engineers and contractors
California Straw Building Association
Non-profit clearinghouse for straw building information. 805.546.4274
Tom Hahn at Three Rivers EcoBuilders, Phoenix 602.252.0446
Architectural design and consulting
Athena and Bill Steen at the Canelo Project, Canelo, Ariz. 520.455.5548 Workshops, tours and consulting
Steve Kemble at Sustainable Systems Support, Tucson firstname.lastname@example.org
Mail order resources, consultation and workshops
Non-profit builders who use volunteers to build homes
Red Feather Development Group email@example.com
Homes for American Indian communities
Builders Without Borders, Kingston, N.
Habitat for Humanity, Phoenix
Besides The Cottage, there’s the 3,000-square-foot family home, an adobe structure built in the late 1800s, and an adobe guest house.
In educating people about earth-friendly ways of building, the Steens hope to help create communities of people who do more than talk about saving the environment but rather live their philosophy. While they’re unable to pinpoint the exact number of alternative-style homes in Arizona, including those made from straw bales, Athena estimates these to be in “the hundreds.”
A building frenzy
Building is a term that defines the Phoenix area. Just this year, the city captured the No. 1 spot in the country in number of building permits issued, reflecting the enormous growth of the region.
But amid this building frenzy, a handful of voices can be heard advocating for “green buildings” that minimize the adverse environmental impact of runaway growth. Although Phoenix’s neighbors to the south, Tucson and Pima County, adopted a straw bale building code in 1996, and its neighbors to the north in Scottsdale advocate for “green buildings,” the city of Phoenix has no such similar codes or initiatives.
In 1998 Scottsdale adopted the Green Building Program to promote resource- and energy-efficient materials and methods in the design and construction of homes. The goal of the program is to minimize the depletion of natural resources caused by the region’s tremendous growth, says Anthony Floyd, Scottsdale’s sustainable building manager.
“Not every city is proactive,” says Floyd. But Scottsdale’s “green program” helps builders of commercial as well as residential homes build structures that minimize the environmental impact through innovations that save energy, water or other natural resources.
Scottsdale has three buildings made with straw bale walls. One of these three, Foothills Academy, is a school. All were built in a non-load-bearing style, Floyd says. This style of building uses the bales of straw as infill among the wooden framework. “It’s really not a big deal” to construct a building in this fashion, Floyd says.
On the other hand, the load-bearing straw bale style of home requires a bit more planning, he says. Also referred to as Nebraska-style straw bale homes because that’s where they were first built, this style of home requires more attention. Here, the weight of the roof and integrity of the home’s walls literally rest upon the bales of straw.
“We ask them (the home builders) to come in and sit down and have a meeting so that we can discuss what’s required,” Floyd says. A special inspection by an architect or engineer is also required, he said.
A straw bale dream
For years, Bob Spetz and his wife dreamed of building their own straw bale home. But it wasn’t until they moved from Arizona to Montana that Spetz, an engineer by training, built his own 2,000-square-foot straw bale home.
He installed radiant heat tubing in the concrete slab floor and uses a woodstove as the primary heat source. The home’s energy-conscious design includes lots of south-facing windows. His water heater is on-demand, saving substantial amounts of gas and money.
“Our utility bills in the summer are $35 a month; in the winter they're about $50,” Spetz says. “Our neighbors, in their ‘well-insulated’ 2-by-6-constructed houses, are paying upwards of $150 to $200 during the really cold months.”
While the Spetzs wanted an energy-efficient house, they also wanted one that looked normal. “If you drive by it, you’d never even know it is made with straw bales,” Spetz says. “Before we built in the neighborhood, there was a lot of concern that ‘those crazy people are going to build some ugly dumpy pile of straw house.’” The neighbors now think it’s one of the “nicest in the neighborhood.”
But building the house hasn’t been easy. Their bank pulled out of its commitment for a construction loan after the couple started building in April 2003. The couple then turned to savings combined with credit cards to pay for their home. In January of this year, they secured a mortgage—but only for five years.
Spetz is hopeful, though. Wells Fargo Bank wants to provide the final mortgage since the bank wishes to have an “alternative structure in their portfolio,” he says.
The bottom line
According to the Canelo Project’s Steens and Tucson expert Kemble, one of the advantages of a straw bale home is that you can “build as you go.” Designs tend to be simple and easy to add on to later. That means those with a tight budget can start out small.
But don’t be fooled into thinking that straw bale homes are always less expensive than standard homes. The savings in building costs come from the homeowner’s own labor and what they can obtain from their friends, says Kemble.
Standard homes cost $100 to $120 per square foot for a typical structure with nothing that fancy, Spetz says. About 35 to 40 percent of this cost is labor, so figure $65 to $75 per square foot for the do-it-yourself builder. Spetz’s house cost $41 per square foot. “Straw bale houses can be built for as little as $18 to $20 per square foot or less, I've heard, and, as with anything, there is no upper limit,” she says.
But many straw bale homeowners will tell you it is more than about the cost. Hoffmann says that when visitors come into her home, they say, “Oh, it just feels so different.” It has a feeling of comfort that is hard to describe, she says. “My daughter (who lives in the area) will tell me that her home is cool in the morning but then uncomfortably hot in the evening. And during that same time, my home has only changed in temperature by 4 degrees,” she says.
For the Steens, there’s satisfaction in teaching people how to use simple materials to build their homes. They promote building that integrates “life, work, home and family” and say that building a straw bale home does this and more.