Building with Earth

Image Gallery A cob cottage in Oregon, with cob garden walls and outdoor fireplace. PHOTO: NIGEL VALDEZ

In the rain-drenched landscape of Cottage Grove, Oregon, Ianto Evans and Linda Smiley live in a delightful little cottage fashioned from a most unlikely material, a mix of mud and straw, known as cob. Their home is warm, cozy and comfortable—not at all what you might think of a dwelling made out of ... well, dirt.

Ianto and Linda are two of a growing legion of people worldwide who are embracing earth building, a centuries-old tradition of architecture and construction. This unlikely band of Earth heroes is helping to forge more sustainable homebuilding techniques.

Building homes from earthen materials has a long, illustrious past. For virtually all of history, our ancestors lived in shelter fashioned from locally available materials, especially earth. Today, approximately half the world's people still inhabit dwellings made with soils harvested from the Earth's crust.

WHY BUILD WITH EARTH?

For one. earthen homes are clean, come and beautiful—even breathtaking. The thick. solid walls create a sense of comfort and security. Walls made of earth am not only strong, they are capable of re insects, earthquakes, hurricanes, tornadoes and fire. They have the very real potential to last hundreds of years.

Earthen homes are appropriate for a variety of climates and are ideally suited for passive solar heating and cooling. If designed well, they stay warm in the winter and cool in the summer with little, if any. need for auxiliary energy. Built largely from soil excavated on site, earthen homes require substantially less fossil fuel derived energy to build than the conventional wood-frame homes popping up by the millions.

Reduced energy consumption provides a wide range of environmental benefits, including reductions in greenhouse gas emissions. Earth homes require much less wood to build, helping ease pressure on the world's over-harvested forests. Materials are collected locally: No huge mines or clear-cut forests are required to supply building materials, and the blemish produced when extracting earth can generally be repaired quickly and easily with little environmental impact. A hole dug to extract clay-rich dirt for an adobe home, for instance, can be filled in, regraded and replanted, or it can be left to fill with water, creating a pond for wildlife to drink from on hot summer days.

Construction of earth homes is user-friendly—often more like play than work. Most earthen building techniques require very little skill and are ideally suited to owner-builder projects. You can learn what you need to know in a weeklong workshop and by reading some of many books on the subject.

Earth homes can be quite economical, further adding to their appeal. Here are the pros and cons of the major earth home options: adobe, cob, rammed earth, tire homes and earth bags.