Sunday, August 24, 2008

The future of housing may lie in the past.

We are frequently confronted with life style decisions that can impact our environment, some more urgent than others. One of the biggest decisions we make with regards to the environment is in our choice of housing. In the United States, the average home emits about four metric tons of carbon dioxide (CO2) equivalent per person per year -- about 17 percent of all U.S. emissions -- according to research by the Environmental Protection Agency.

Conventional building methods often overlook the interrelationships between a building, its components, its surroundings, and its occupants. Conventional buildings consume more of our resources than necessary, negatively impact the environment, and generate a large amount of waste. According to Laurence Doxsey, former Coordinator of the City of Austin Green Builder Program, "a standard wood-framed home consumes over one acre of forest and the waste created during construction averages from 3 to 7 tons." Often, these buildings are costly to operate in terms of energy and water consumption. And they can result in poor indoor air quality, which can lead to health problems.

Green building practices offer an opportunity to create environmentally-sound and resource-efficient buildings by using an integrated approach to design. Green buildings promote resource conservation, including energy efficiency, renewable energy, and water conservation features; consider environmental impacts and waste minimization; create a healthy and comfortable environment; and reduce operation and maintenance costs.

How does alternative housing construction fit into this concept? Alternative housing methods have been available for decades, mostly for financial reasons, I think, but were usually associated with "hippies" or other "eccentrics". Cob, adobe, straw-bale, subterranean, earth-ship, rammed-earth, cordwood, earth bag, salvaged - these are all construction methods that are still being used by people who care about their planet, and can't afford (or don't want) expensive mortgages. Let's look at a few of these alternatives:

Cob -- Building with earth is nothing new to America; the oldest structures on the continent were built with adobe bricks. Cob has been a traditional building process for millennia in Europe, even in rainy and windy climates like the British Isles, where many cob buildings still serve as family homes after hundreds of years. Cob building uses a simple mixture of clay subsoil, aggregate, straw, and water to create solid structural walls, built without shuttering or forms, on a stone platform.

Straw bale -- Straw bale building typically consists of stacking rows of bales on a raised footing or foundation, with a moisture barrier between the bales and their supporting platform. Bale walls can be tied together with pins of bamboo, rebar, or wood (internal to the bales or on their faces), or with surface wire meshes, and then stuccoed or plastered, either with a cement-based mix, lime-based formulation, or earth/clay render. This method generally works best in locations with a hot, dry climate.
Subterranean -- Underground homes, according to Mike Oehler (author of "The $50 & Up Underground House Book"), when properly designed and constructed, provide pleasant surroundings, a better view, and are esthetically pleasing, inside and out. They are weatherproof, soundproof, relatively fireproof, and require less maintenance. Warm in winter, cool in summer, with superior flooring, and the pipes never freeze. They have no foundation, use less building materials, require less labor, and are ecologically sound.

In Cooper Pedy, Australia, the majority of residents live in caverns. Some are left over from opal mines, others are dug out for living spaces. Throughout dry and mountainous northern China, an estimated 40 million people still live in caves or subterranean dwellings.
Earthship -- An earthship refers to a passive solar home made of natural and recycled materials. Designed and marketed by Earthship Biotecture of Taos, NM, the homes are primarily constructed of earth-filled tires, utilizing thermal mass construction to naturally regulate indoor temperature. Earthships are a type of off-grid home, which minimizes their reliance on public utilities and fossil fuels. They are built to utilize the available local resources, especially energy from the sun.

The major structural building component of the Earthship is recycled automobile tires filled with compacted earth to form a rammed earth brick encased in steel belted rubber. This brick and the resulting bearing walls it forms is virtually indestructible. Aluminum cans and glass bottles are a great, simple way to build interior, non-structural walls. Aluminum can walls actually make very strong walls. The 'little bricks' create a cement-matrix that is very strong and very easy to build. Bottles can create beautiful colored walls that light shines through.

Recycled/Salvaged -- The local dump is a great place to look for building materials. Dumps/landfills will sometimes have an area set aside for potentially reusable items, and they encourage people to sort through them. The virtue of recycling used building materials lies in diminishing the need for industry to recreate it. All of the energy that is spent in manufacturing and transporting something can be saved. The raw materials that would be drawn from the earth can be saved. The need to cover the item in the local landfill can be saved. The financial savings to the potential home owner can be significant.

Perhaps the time has come for natural building techniques to become the "norm" rather than the exception. Kelly Hart, who runs the websites Green Home Building and Dream Green Homes wrote an article "Building With Nature" which eloquently addresses the need to return to nature as our guide in construction. In it, Mr. Hart states:
"Building with nature means being aware of how much embodied energy exists
in the materials that we use, so that we don't unnecessarily squander fossil
fuels and contribute to global warming. It means building compactly so as to
not waste materials and energy. It means using materials that are
biodegradable or recyclable. It means designing our homes in ways that use
the sun and the earth to heat and cool them. It means utilizing forms of
renewable energy wherever possible. It means incorporating greenhouses and
naturally cooled pantries in our homes to help feed us."
Until next time...become the change you imagine.





2 comments:

Steve sculpts critters said...

Those earthships with their rubber tyre walls are great.

Izmet said...

Yes, and what a great way to recycle!