Foundation, Structural Framing

Little did Nebraska's pioneers know that their straw bale method of home construction would turn out to be politically correct in the year 2001.

The oldest recorded straw bale building was a school house in Bayford, Nebraska, constructed around 1886, when steam-powered balers were invented. Identifying the products of these new-fangled devices as building blocks didn't take long, since the sod homes typical at the time could not stand on Nebraska soil and trees were scarce.

According to the Straw Bale Association of Nebraska, the first homes made of straw were intended to be temporary. But when it was determined that the bale homes could be relied on to keep out the extreme Nebraska elements, these unwitting environmentalists decided to live in them permanently.

Huntsville, Alabama saw the first straw bale home built with post and beam construction, but not until 1936, when Dr. William Burritt built a two-story mansion. This type of construction remained popular until the 1950s, when home construction began to see the mass production of stick-built homes and straw bale construction was all but forgotten.

Fast forward to 1993, when the first load-bearing straw home was built in Tucson, Arizona, a structure approved even when such materials were not included in local building codes.

Fast becoming one of the most popular sustainable construction techniques, economical straw bale construction makes beneficial use of what many consider a waste material.

Straw bale construction reduces building costs, is easy to work with, offers excellent insulation (up to 75% savings in heating and cooling costs), saves trees, is practically soundproof, and is more earthquake resistant than masonry, according to industry sources.

Straw is unpopular with termites and other types of burrowing insects. And using proper barrier construction methods to keep the straw completely dry, a straw-bale structure can last indefinitely. In fact, some hundred-year old straw bale homes can still be seen in Nebraska to this day.

Stacked like huge bricks, straw bale wall systems can go up quickly, without years of construction knowledge or fancy tools. Old-fashioned "barn-raising parties" can see a modestly sized structure erected in a day, according to Catherine Wanek of the El Paso Solar Energy Association . The straw is available wherever grain crops wave, and it's a constantly renewable resource.

Straw bale construction can be used to build homes which are both structurally sound and inexpensive. For instance, BUILDER Magazine recently explained how Albuquerque homebuilder Joe Fortin was brought in to repair an older straw bale home. In this structure, the straw had settled within the walls, was beginning to deteriorate, decreasing the home's energy efficiency as well. Fortin cast posts and beams onto the straw bales and compressed them so that they would not settle.

Fortin, who prides himself in building environmentally-friendly homes, has built five straw bale structures. As owner of Casa Verde Custom Homes, he gets his raw materials from a nearby Navajo reservation or a source in Yuma. His crew uses 2 x 4 construction in both horizontal and vertical patterns while concrete is placed in forms creating braces to control any movement in the wall structure. Metal ties run through the bales from inside to outside while the concrete is placed.

Straw bale homes can be finished with earth plaster or cement stucco, but the bales can hold plaster without the use of wire mesh during this process. The thick, rounded walls of straw bale-built homes lend an earth-connected appearance to the structure.

Admittedly, the wall thickness can rob interior square footage, but the trade-off is worth it, according to Fortin. He says the cost of straw bales ($3.00 each) with their built-in energy efficiency can "blow away" rammed earth, adobe, or block systems in terms of economy.

Why use straw bale construction? Proponents say that it offers:

• Superior energy efficiency (R-40 to R-55)
• Low cost ($25-$45 per sq. ft. owner-built and about $65 for contractor-built homes)
• Environmental advantages -- there are no old growth wheat fields
• Easy modifications.

Straw bale construction is gaining popularity, in part because of it is both natural and resource saving. For more information regarding straw bale construction and other sustainable building techniques, visit such sites as:

Solstice: Sustainable Energy and Development Online.

San Diego Energy Times

Straw Bale Construction

Straw Bale Building Technology

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