Builder offers dirt on homes made from earth

By KIM BOATMAN
Knight Ridder Newspapers

Last Updated: Nov. 8, 2003

San Jose, Calif. - Approaching midlife sometimes prompts a desire to return to the elemental, to get back to the earth. For San Jose architect Noel Cross, that was quite literally true. Earth, or perhaps more straightforwardly, dirt, was the stuff of his dreams.

Earthen Homes Architect Noel Cross is building a rammed-earth home in San Jose, Calif. Its 18-inch-thick walls - which are made from a combination of dirt, sand, cement and water - will help keep the house warm in winter and cool in summer. About The House Walls: A rebar framework was constructed, and crews shot a mixture of dirt, sand, cement and water under high pressure to form the walls, a technique called pneumatically impacted stabilized earth, or PISE. Dirt: The dirt was $80 a truckload, but it cost $300 a truckload to bring it in. Insulation: The house's thick walls retain heat in the winter and remain cool in the summer. Paint: Never necessary, inside or out. Costs: Architect Noel Cross of San Jose, Calif., has averaged about $275 a square foot, while normal construction costs average about $250 a square foot.

Established in his profession, building homes with elegant and graceful designs for appreciative clients, Cross decided to follow his heart and dreams after he turned 40. Always engaged by environmental issues, Cross longed to build a rammed-earth house.

But no client could be persuaded to undertake an unfamiliar building process that sounded a bit too much like it might result, at best, in something resembling an adobe cliff dwelling.

Instead, Cross is building his earth home for himself, using a construction process that has so fascinated a number of people with architecture and environmental interests, he gives occasional tours of the property in San Jose's Willow Glen neighborhood.

His project, which began almost two years ago and should be completed in a few months, has provided a bit of an education for wary city building inspectors, unaccustomed to the construction technique.

Cross' hope is that prospective clients will be so taken with his home, they'll give a nod to rammed-earth construction.

"If I build it, they will come," says Cross.

Different look

There's nothing sterile or standard about the 3,200-square-foot home, with its massive walls that already look as if they've been washed pale by years of sun.

This is the sort of home that has made so popular all those books about Americans who take on old, crumbling Italian and French villas. It would look at home among French or Italian vineyards and fits well with the Mediterranean influences prevalent in California architecture.

But there are differences.

For example, Cross worked hard to ensure that there would be plenty of light, with large windows and open spaces.

Even in construction, the two-story home already has substance. Perhaps it's the solid, 18-inch walls. Or the substantial, been-there-forever feel of the place, with the imperfections and cracks in the surfaces lending a sense of history the house can't lay claim to yet.

Cross loves those surface imperfections, the roughness of the finish.

"What I like is that it immediately looked 300 years old," he says.

Cross has much faith in the longevity of the construction process and the material. While he refers to the home as "rammed-earth construction" because there's some familiarity with the term in the building trades, technically it is not a rammed-earth house.

The construction technique employed is called PISE, a technique pioneered by rammed-earth guru David Easton of Napa, Calif., who has spent the past three decades researching and developing earth construction systems and promoting the construction technique.

PISE stands for pneumatically impacted stabilized earth, and the construction method could be compared to swimming pool construction.

At Cross' house, a rebar framework was constructed, and crews shot a mixture of dirt, sand, cement and water under high pressure to form the walls. It's similar to gunite or shotcrete construction.

"Basically what they've done out there is build a swimming pool shell upside down," says Steve Stender, a supervising building inspector for San Jose.

For building inspectors, the technique prompted a bit of caution as they made sure the construction met weight-bearing codes. Obviously, earthquake safety is paramount in this area, and Easton, the pioneer, says it was the first issue his company addressed as the technique was developed.

The permitting process was slow, says Cross, who thinks his might be the first of its kind in San Jose.

"This is the first one I've seen done in San Jose in my area," Stender says. "It's a difficult process to get approved because it's not one of the traditional methods that is recognized by any of the codes we use.

"It would be difficult for the average homeowner to do this, to get a design professional who's willing to draw it and an engineer who's willing to provide the structural calculations. I absolutely love the look of it, but it's not something a homeowner could do."

Costs a bit more

Of course, that's just what Cross hopes others will do, now that he's paved the way and developed the expertise.

This has been such a labor of love for him that he's put considerable labor, in addition to his architectural work, into the project.

He'll tell you just where the dirt came from - not just any dirt will do. His was trucked in from Nunn's Canyon Quarry in Napa County.

"The dirt is really - this is going to sound funny - dirt cheap," he says. "The dirt is a byproduct." The dirt was $80 a truckload, but it cost $300 a truckload to bring it in.

In general, the construction costs are a bit higher for this method of construction, Cross says. He has averaged about $275 a square foot, while construction costs are typically $250 a square foot.

But it's expected that houses such as this might last hundreds of years. And there's good news for those who dread picking up a roller.

"You never have to paint inside or out. Forever," Cross says with emphasis. "Long-term, in 10 or 15 years, you've already made up the difference."

Cross' project began with the right piece of property, purchased for $580,000 in 1997. This long yard, with a bungalow hugging the front property line, met his needs well. Cross, his wife and two young daughters have lived in the small house while construction proceeded on the other house out back.

And there will be nothing spanking-new or out of place about the new construction. Everything so far says the home will look well-established from the start. Certain design elements help, such as the thick earth wall constructed around the property's perimeter, using the leavings from the home construction.

Ever environmentally conscious and thrifty to boot, Cross is employing found and salvaged elements in the construction. He, his brother and friends have worked on timbers from an old menswear's store. An antique marble sink stands ready for use in the home. He's a regular customer of San Jose's Artefacts Design and Salvage, which sells intriguing reclaimed architectural elements.

Cross is quick to point out the environmental benefits to his project. First, these homes, with their thick walls, retain heat in the winter and remain cool in the summer.

Cross will use radiant floor heating, solar panels for electricity and no air-conditioning. The insulation in the new home is made from recycled blue jeans.

What Cross is doing has significance not just in this area, says Easton, who has done perhaps a couple of hundred projects over the years.

Hot property

Rammed-earth construction has some popularity in parts of the world, especially in hot, dry climates. It accounts for more than 20% of construction in Australia, Cross notes. And Easton says, "The French are leading the way."

But sometimes in developing countries, people are leery of the traditional rammed-earth construction, which involves tamping down the earth inside forms.

"It really is a good technique in developing countries because you're using local materials and unskilled laborers," Easton says. But earth is sometimes viewed as a poor man's material.

By showing photos of homes such as the one Cross is constructing, Easton says, "It validates their own use of the material.

"It shows that earth is acceptable."

See www.rammedearthworks.com for photos of homes using this construction and for an extensive question-and-answer section about rammed-earth construction.

From the Nov. 9, 2003 editions of the Milwaukee Journal Sentinel