Thinking of jumping on the green house train? This article by Realtor.com on “earthship homes” introduces a housing style that embodies the far extreme of sustainable house. While an earthship home may not be feasible in the South Bay, we found this article and the lifestyle it bodes to be fascinating…

What Is an Earthship Home? Eco-Friendly Living and Zero Utility Bills

If living off the grid sounds more enticing than ever, an earthship home could be the perfect style of living arrangement for you. OK, we know it sounds like something straight out of “Close Encounters of the Third Kind: Director’s Cut,” but don’t let the name fool you. Earthship homes are actually eco-friendly residences that stay firmly planted on the ground.

So what are they? In short, they’re sustainable houses that make use of nonpolluting, renewable energy sources and smart design to meet heating, cooling, and power needs, according to Michael Reynolds, the architect behind the earthship home style and founder of Earthship Biotecture in Taos, NM.

That still leaves us with a lot of unanswered questions. So we spoke with Reynolds to learn more about what an earthship home is made from, how it protects the environment, and what it costs to build one.

What is an earthship home made of?

While traditional homes are made of stone, brick, lumber, or concrete, earthship homes are built of both natural and recycled materials such as aluminum cans, plastic bottles, and cardboard. The primary building material is recycled automobile tires filled with compacted earth, or compressed soil.

“We take steel-belted automobile tires and beat them full of earth so that they weigh about 300 to 400 pounds a piece,” says Reynolds.

The tires are stacked like bricks and covered in adobe mud to form the house’s foundation.

“They’re basically indestructible,” Reynolds says. “They’re also earthquake-resistant” because they’re made from rubber.

How does it protect the environment—and save money?

Because earthship homes are designed to collect and store their own energy, they heat and cool themselves without electric heat or burning fossil fuels or wood.

Sun enters through the glass in the home and heats up the floors and walls. In the evening, when the air temperature drops below the temperature of the heat stored in the walls, heat is naturally released into the space. In the summer, natural ventilation through buried cooling tubes and vent boxes helps the home stay cool.

In place of traditional electricity, an earthship home has its own renewable “power plant” with photovoltaic panels, batteries, charge controller, and inverter. As a result, an earthship’s electrical needs are about 25% of that of a conventional home and can be met with 1 kilowatt or less of energy from solar panels. This helps lower heating and cooling costs, Reynolds says, since there’s no need for electric heat or air conditioning.

And the savings are impressive: Utilities for a 2,200-square-foot earthship home cost, on average, only $150 a year, say Reynolds.

Earthship homes were also created with water conservation in mind. Each home collects water from rain and snowmelt on the roof, storing it in cisterns which feed a pump and filter system which, in turn, cleans the water and sends it to a solar water heater and pressure tank. From there, water is used for bathing, washing dishes, and laundry. Because every drop of water collected from an earthship roof is used four times, these homes can subsist without taking water from the ground or municipal sources.

Translation: There’s no water bill.

Where can you build an earthship home?

Earthships are often found in desert climates. In fact, the largest concentrations of earthship homes are in New Mexico and Colorado. However, they can also be found throughout the U.S. (and in Europe, Africa, Central America, and South America).

“Earthships aren’t just homes for hippies living in the mountains,” says Reynolds. “They’re homes with amenities that address your daily needs.”

Like conventional houses, earthship homes must pass local building codes—and some municipalities do not permit these structures. So if you’re interested in building an earthship home, you’ll want to check your local deed restrictions to see whether you’re allowed to build such a home in your town.

How much does an earthship home cost to build?

Homes built by Earthship Biotecture range in cost from $100,000 for smaller models to $1.5 million for the Phoenix Earthship, the company’s most luxurious earthship rental.

Want to build one yourself? You can enroll in a $2,500 one-month training program at Earthship Biotecture. It’s important to know upfront that earthship homes aren’t necessarily cheaper to build than conventional homes.

“Earthships are very similar to conventional housing [in construction costs], but the difference is a regular house will have thousands of dollars in utility bills,” Reynolds says.

Can you get a home loan for an earthship home?

It can be difficult to obtain a mortgage for an earthship home. Many banks are unwilling to lend money for earthship homes, since there are few (if any) comparable sales in the area the lender can use to determine the home’s value. You also can’t use an FHA 203(k) rehab loan, since the construction materials aren’t on the HUD-approved materials list. Consequently, many people have to pay for earthship homes with cash. If you can’t afford to dip into your savings, Earthship Biotecture recommends getting a personal loan or line of credit from a bank.

There is one exception that could help you qualify for a mortgage: Adding a well instead of harvesting rainwater. Granted, you won’t be living totally off the grid, but this can at least enable you to become a proud earthship homeowner.

Daniel Bortz is a Realtor in Maryland, Virginia, and Washington, DC. He has written for Money magazine, Entrepreneur magazine, CNNMoney, and more.