The New Natural Building
Earthen construction is ancient. Rammed earth structures in China can be dated to as early as 5000 BC. Adobe buildings erected in the desert Southwest of the United States still stand after centuries. In Europe, 400-hundred-year-old timber-framed, wattle-and-daub structures are still inhabited. In fact, the connection with time-honored practices is what draws many people to natural building systems.
These systems can claim many advantages over modern construction. The materials are often locally sourced. They’re non-toxic. The resulting structures are strong, fireproof and aesthetically pleasing. And yet, most of these methods have been pushed to the fringe, at least in the U.S. Why?
Part of the problem is perception. Many people think of natural materials as the domain of barefoot hippies, building weirdly shaped organic houses without blueprints. Some people don’t “trust” construction methods that employ natural materials, assuming they are stuck back in some unenlightened century.
“One of the biggest barriers to wider adoption is misinformation,” says Colorado-based architect Greg Madeen. “For example, people say, ‘straw bale rots.’ Yet wood is cellulose, just as straw bale is cellulose.”
David Easton, engineer turned rammed earth expert, calls the effort to push natural materials onto a skeptical, conservative industry a “Sisyphean struggle.” But in a presentation titled “The Virtues of Earth,” Easton explains another ironic turn that has held up the mainstreaming of rammed earth.
Once architects began to design rammed earth buildings, “it became accidentally expensive,” he says. “It went from rough, rugged and affordable to sophisticated, refined and expensive.” He spent many years developing techniques to increase the speed of construction—and consequently, to reduce costs. More recently, he has changed tactics and begun developing Watershed Block: a unitized material that doesn’t require teaching old dogs new tricks.