Straw-Bale Homes

Articles called House of Straw; Adding Up Pluses of Straw Houses; Straw: Owners, Architects Love the Natural Imperfections; and Facing concerns about pests, moisture damage, earthquakes in the August 7, 1996 San Francisco Chronicle describes using straw bales covered with stucco for housing that is quick, cheap, and has outstanding insulating qualities. For Straw Bale housing there are many web Sources. Excerpts of the articles follow.

That first little pig, it seems has gotten a bum rap over the years. His infamous decision to build his house out of straw has demonstrated to many a child the perils of flimsy building materials. But now builders are beginning to realize the poor piglet wasn't too far off base. He was missing just one key piece of equipment, a straw bailer. A baler can compact wispy strands of straw into sturdy, dense 2-by-3-foot bricks that can be stacked, pinned and stuccoed into walls capable of withstanding hurricane-strength big bad wolves, not to mention fire and pests.

Straw-bale homes are houses whose walls are composed of stacked bales of straw covered with stucco. These houses, with signature two-foot-thick walls, have interesting features, such as wide window seats, lots of nooks and even furniture built into the wall themselves. Not only are they ecologically correct because they use less wood but they are also well insulated and fire resistant.

Bale homes can be made of any type of straw - rice, wheat, oat or rye. Straw is not hay but the non-nutritional part of grain that often remains in the fields after harvesting ... Although farmers in the Great Plains built straw-bale homes more than 100 years ago, most Americans are unfamiliar with them. ... Straw-bale construction [has] such benefits as exceptional thermal and acoustic insulation and fire resistance. Using an abundant waste product such as straw also seems smarter than chopping down trees (straw-bale walls typically use half the wood of conventional walls).

Straw-bale homes are naturally imperfect - what some would call organic. The bales are stacked - laid out like bricks - on a conventional foundation. Metal stucco netting is placed on both sides of the stacks, then plaster is applied on the inside and stucco on the outside. Often the walls are pinned with rebar and reinforced by wood or steel to bear the roof's weight. Unlike bricks, bales do not line up in perfect rows, and the plaster and stucco surfaces don't always camouflage the irregularities. Although straw-bale homes can be made to look like conventional buildings with the use of drywall and other materials, most architects and homeowners prefer to let the bales' natural beauty show. ... Most architects like to capitalize on the thick walls, incorporating such elements as window seats and other built-in elements.

The solid straw-bale walls don't have passageways for rodents to travel through as do the walls in wood-frame houses. Without space to run, rodents are less likely to make their homes in your house. ... Moisture damage is uncommon in straw-bale homes. Even in the wettest climates, straw-bale homes have fared as well as traditional homes. The stucco seals and waterproofs the exterior while allowing the straw bales to breathe. "Think of it like a sponge," explains Swearingen, a general contractor experienced in straw-bale construction. "If the sponge is left open to the air, it dries out. There are 100 year old buildings .. that are still doing just fine."

Most architects and engineers .. believe that straw-bales are the ideal seismic-resistant building material. "Where are the bales going to go?" asks Alameda architect Darel DeBoer, a board member of the Architects/Designers/Planners for Social Responsibility, a nonprofit ecological design organization based in Berkeley. "The whole thing is woven together with these threaded rods, the top of the wall is bolted all the way to the bottom. I have complete confidence in it. The worst that could happen is that the plaster would crack."

The thick walls have an energy efficiency rating of about R-55 - that's two to three times the typical R-value for modern, energy-efficient homes. Air doesn't flow through easily, .. During the hot summer days, it takes about 12 hours for the heat to get inside, and you ventilate the house at night. South facing windows provide a passive solar heat source in the winter, and the bales hold in any heat from more costly sources, such as gas furnaces, so homeowners can expect a significant savings on energy bills over a lifetime.

Tests by Canadian and US materials testing labs have shown that straw bale walls are much more fire resistant than average wood-frame walls. In the tests, flames took more than two hours to burn through plastered baled walls as opposed to 30 to 60 minutes for comparable wood-frame walls. "Basically, the bales are so dense that they won't support combustion very well," explains John Swearington, .. "Even if you put a blowtorch on them, they tend to char and the charring itself stops further burning."

Straw-bale building, somewhat like an old-fashioned barn raising, is a process that brings communities together. "Straw bale is very user-friendly for builders," says Swearington. "Fewer advanced carpentry skills are required."