Earthships are self-sufficient homes built of recycled tires that embody the core values of sustainable living. They generate their own electricity, maximize solar heating and use only rainwater. Yet, they aren't for everyone.
"It's not really what most of mainstream America wants to embrace," said Diego Mulligan of New Village Institute, a non-profit organization promoting sustainable living.
Earthships tend to be built by those who want to live an alternative lifestyle, often in remote areas where there are no utilities to begin with.
But most people live in cities and are fond of their modern conveniences. This is why Mulligan and others are taking ideas from earthships and other sustainable designs and applying them to communities that the majority of people could imagine living in.
One such development has begun construction in Santa Fe, N.M. It's called Oshara Village and although there won't be any recycled tires, there will be solar heating and water reclamation. And unlike most earthships, there will be restaurants and businesses all within walking distance.
Earthship founder Mike Reynolds began developing his unique architecture style in the same area of New Mexico, during the "back to the land" movement of the 1960s and 1970s. He built the first actual "earthship" in 1988 in Taos, N.M.
There are now about 3,000 earthships worldwide, some 500 of which have been built by Reynolds' company Earthship Biotecture.
The walls of an earthship are made of used tires stuffed with dirt and stacked in a U-shaped pattern. Sunlight warms the house during the day, and the dirt-packed tires hold onto that heat and release it slowly throughout the night.
Rainwater is collected from the roof and recycled through sinks, toilets and planters in a four-step process that uses all sewage. Solar panels and/or wind turbines provide electricity, allowing some owners to be off-the-grid.
"The basic idea of the earthship is that it reaches out with its arms and gathers everything it needs from its local surroundings," said Mischa Hewitt, project manager of Low Carbon Network and author of a recent book on earthships.
Hewitt and his colleagues have just completed Earthship Brighton, the first of its kind in England. The group chose the Reynolds' design over other sustainable architectures because they wanted a "pioneering, high-profile project" that demonstrates how the sun can keep a home warm even in cloudy England.
"Consciousness is the first step," Hewitt said. But he admitted earthships aren't the one-size-fits-all solution.
"The earthship is a fantastic model, but it isn't directly applicable to high-density living environments," Hewitt told LiveScience.
The challenge now, he said, is to find ways that city-dwellers can build and retrofit their houses to lower their carbon footprint.
Bringing sustainability to a home near you
The mainstream application of sustainable practices is the underlying principle of Oshara Village.
Built around a central plaza, the development's 470 acres will eventually have more than 750 housing units, priced around half a million dollars each. But interspersed between the homes will be restaurants, shops and offices.
"Cutting out driving is probably the most important thing anyone can do in the realm of sustainability," said Mulligan, who has been pushing for a community like this for the last decade.
To make Oshara a walkable community, the developers had to fight several zoning laws that forbid mixing of residential and commercial land use.
They also added several sustainable features, such as fire retardant sticky cellulose. This "super-insulation" is sprayed into every crack and crevice to trap heat better than commonly-used fiber glass, Mulligan explained. Windows and walls will be positioned so as to let in winter sunlight, while providing shade in the summertime.
And regarding water use, every drop that goes down a sink or toilet will be reused, either for landscaping or for toilets in commercials areas, reducing water consumption by half, Mulligan said.
New Village Institute ran a study and found that residents of Oshara Village could lower their total energy bill — for car and home — by about 50 percent, as well as reduce their carbon footprint by 26,000 pounds of carbon dioxide per year. Hewitt thinks that Oshara is the direction that sustainability needs to be going.
"I'm not interested in green people, because they are already there," he said. "It's the mainstream where real change can happen."