With the movement toward a simpler way of life and green living, it's now possible to live in a home that's just big enough and also one that is sustainable. And one of the most interesting green building materials is straw.
The wolf in "The Three Little Pigs" may have threatened to "huff and puff and blow your house down," but today's straw house isn't going anywhere. The end product will be a substantial home that is built to code.
Straw is the byproduct of the agricultural production of wheat and rice that is left when the edible parts are removed. Different types of straw are available in different states, depending upon the crops grown in that area.
Using straw bales in building has a few distinct advantages: It is a productive use of a waste material that might otherwise end up being burned in an environmentally unfriendly way, and the extra-thick walls the bales make are great energy-savers. A bale wall covered with adobe or stucco has a functional R-value (a measure of its ability to prevent energy transfer from outside to inside and vice versa) of 55 compared to the R-19 associated with traditional exterior walls.
Even in severe weather, bale buildings maintain an average year-round temperature of about 72 degrees. In warmer climates it can actually eliminate the need for air conditioning and reduce heating bills to practically nothing.
One question that often comes up is if straw is more of a fire hazard than other materials. During the construction phase there is surely a risk of fire, as with any combustible building material. After the straw is covered in adobe or stucco, however, there is much less chance of fire. There is virtually no air space in the bale walls, and combined with a fire-resistant roof (clay or concrete tiles, metal roofing, fire-proof composite shingles), the houses are quite safe.
Once the straw is covered, it is inaccessible to mice and other rodents that might find the straw attractive as a nesting material. As with a traditionally built house, a homeowner must make sure there is a way to guide water away from the foundation in order to avoid moisture under the slab and seeping up into the walls.
Several design issues must also be faced. First, the walls are thicker, which must be taken into account in the architecture. The covering is also necessarily thicker-looking than the typical finished drywall.
A straw house costs about the same as a frame house, but some elements might even cost more. The footings and the foundation need to be larger to accommodate the size of the bales. It may also be harder to find a good contractor willing to do things a little differently.
It's possible to add special features by buying salvaged windows and doors, but then the plans must "build" to those sizes and shapes. Interior finish materials might be more traditional natural stone or ceramic tile, but it is important to keep in the same character as the more rustic wall finish. Concrete counter tops would be a good choice, or natural stone with a honed versus polished finish would work. Matte handmade tile might be more successful than a more refined-looking highly glazed tile. Introducing vintage beams would add warmth or using exposed steel could give a quirky twist to the interior.
Christine Brun, ASID, is a San Diego-based interior designer and the author of "Big Ideas for Small Spaces." Send questions and comments to her by e-mail at firstname.lastname@example.org or to Copley News Service, P.O. Box 120190, San Diego, CA 92112.
Copyright 2007 Copley News Service
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