Biotecture: What’s an Earthship Home?

Michael Reynolds is the pioneer of an off-grid, passive solar architecture style known as the Earthship home. To give you the picture, above is a photo of the south-facing, double-greenhouse wall of one of these extraordinary structures.

Reynolds’s company, Earthship Biotecture, displays various models which it helps people build for themselves. So…

What are the Earthships like on the inside?

The homes range in size from studio-style cottages to spacious, three-bedroom mansions. But they have little else in common with the traditional mansion.

It takes a personal experience to really know what they’re like. Visitors to El Prado, New Mexico’s Greater World Community (near Taos) can book an Earthship overnight to see how it feels to live in these buildings. The reviews are impressive.

What special features make up an Earthship home?

Earthships have a number of signature features:

They’re made with recycled materials.

They use only renewable energy, and rely on thermal and solar heating and air conditioning.

To foster self-sufficiency, the properties include forms of food production.

They include self-contained sewage treatment.

They collect and filter rainwater for home use.

☛ As a homeowner, what’s in your bundle of rights? Does the water under a home belong to a homeowner?

How much do Earthship homes cost?

They’re expensive. Here’s what we found at the time of this writing: Michael Reynolds charges $400 an hour for a consultation. The work and materials involved in getting a home move-in ready run about $275-$375 per square foot.

On the other hand, the company markets Earthship homes as fully self-sufficient, replacing the need for water, gas and electric accounts for good. From the skylights to the underground cooling tubes, the trusty Earthship keeps its proud owners comfortable all year.

Are less pricey models available?

Some clients handle the interior work themselves. This can cut 20% to 30% off a customer’s building costs.

The Explorer costs about 30% less. Other models with streamlined costs include Earthship Hut Modules, originally designed for hurricane-relief housing in Honduras. And there’s the Simple Survival Earthship — built to provide basic comfort, clean water, sewage treatment, and just the essential solar electric needs. The model was developed to house people displaced by earthquakes.

How many places would actually allow homes like this?

Earthship owners are in Europe, the United States, Canada, and Mexico. The company says: “We have decades of experience navigating the municipal building department regulations.” To have your own questions explored, the best way to start would be with a consultation.

OK, where’s more information on these homes?

See more at the website linked above or send your question by email to: Earthship.com.

What About Earth-Sheltered Homes?

The next photo shows another kind of home that brings its occupants into symbiosis with the seasons. It’s the earth-sheltered house. You’ve likely seen some of these. They started as a trend during the gas crisis of the 1970s. Some are underground. Some are bermed.

How does an underground earth-sheltered house work?

An underground house is built below ground level, surrounding an outdoor courtyard which could include ponds or natural gardens. Glass doors and windows let in light and heat from the sun. A stairway leads down to the interior.

For obvious reasons it’s tricky to design these in a way that optimizes light, allows for grounds maintenance, and facilitates drainage. Designers must be chosen with care!

What about berm-sheltered houses? How do they work?

A bermed house usually has earth covering part of the home. But the berm on some homes covers the rooftops, positioning the home largely underground. In either case, the main feature is the way the home is nestled into the ground.

Rooms are arranged to optimize light and heat from the sun, with skylights enhancing the effect.

Are berm-sheltered homes worth the effort?

It all depends! In the right site, with the right soil, an earth-sheltered home can be a stunning investment. Warm in the winter, cool in the summer, highly resilient to weather extremes, and filled with a sense of blanketed tranquility.

A steep incline that faces south is ideal. It needs the least excavation and exploits sunlight best — in our Northern Hemisphere, of course. That said, in southwestern states with their hot summers, facing north would take advantage of an earth-sheltered home’s special cooling properties.

Either way, these homes save impressively on energy use in areas of extreme heat and cold. Many happily earth-sheltered homeowners live in the western United States.

What are earth-sheltered homes made of?

The best construction materials depend on the traits of the soil, regional climate, and design. Concrete or concrete blocks are commonly used. Concrete lends itself well to waterproofing and insulation.

Wood also features frequently in earth-sheltered homes. The structure may contain elements of steel and concrete reinforcement. To seal the structure against natural corrosion, builders integrate various kinds of materials:

Rubberized asphalt. This durable, layered material may come into the picture, to cover outer surfaces of the building.

Waterproofing material. Plastic, synthetic rubbers, and vulcanized sheets are all examples of underground waterproofing. So is bentonite. Formed from clay, it can be made into panels or applied in liquid form.

In contrast to the way most homes are insulated, here, insulation is normally installed on the home’s exterior.

What About Tree Houses?

Some people do actually commission tree houses for their homes. This video, presented by the Wall Street Journal, describes a project that seemed to start with an earth-sheltered design, but turned into a home in the trees.

But while it’s “hidden” in the woods, it’s much less attuned to nature than the designs we’ve discussed above. And it’s an option very few buyers could afford.

Are there more down-to-Earth options? Sure. Can we interest you in an eco-aware, pre-fab treehouse from Germany, starting at just $6,000? The “baumhaus” or tree home can be made of copper, steel, or wood. Some tree homes have fanciful decks, suspended by ropes from the living trees. With their adorably nest-like interiors, tree homes can serve as primary residences or accessory cottages.

There are plenty of other ways to live with the planet in mind, such as breaking free of traditional energy sources, too.

☛ Eco-friendliness and off-grid living often go hand-in-hand. Living off-grid means keeping track of energy use, working with natural energy when it’s most plentiful, and avoiding over-reliance on fuels.

Biotecture and Other Earth-Focused Homes: Future Potential

These houses are expensive to create. Some cost well over 20% more than a regular house. The soil and the siting has to make sense for the plan. And financing can be harder to get. When it’s time to sell, the pool of potential buyers could be quite limited.

But some of these ideas have renewed potential, given their resilience to the weather and climate impacts now making their marks on residential real estate. That’s one reason earth-focused homes could be making a comeback.

Supporting References

Earthship Biotecture via EarthshipGlobal.com: We Build Earthships.

U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy (Washington, DC) – Home Design and Landscaping Blogs: Earth-Sheltered Homes via Energy.gov: Efficient Earth-Sheltered Homes.

Nikki Walker and Todd Holmes for WSJ Mansion from the Wall Street Journal via YouTube.com: Tour a $2.8 Million “Tree House” Hidden in the Woods (May 18, 2023).

And as linked.