What are Earthship Homes?

By thewriteDuffy •  Updated: 01/08/22 •  10 min read

What Is An Earthship Home?

An Earthship is an off-grid, self-sustaining home—or community of homes—typically made of natural and recycled materials such as old tires and recycled cans or bottles. Earthship homes make use of non-polluting renewable energy sources and smart design to fulfill most if not all of its heating, cooling, and power demand.

Why Are Earthships called Earthships?

The reference to earth is due to their composition and location – built of earth and sunken into the earth. The ship reference is that they are designed to be self-sustaining off-grid vessels, like spaceships.

Why Do People Choose To Live In Earthships?

Earthship homes have a daring aesthetic, challenging the observer to question her relationship with nature. In an era where sustainability has become a mainstream concern, many people question how their intimate spaces should be shaped in unison with the earth. But how does architecture fit into this?

Earthships are homes built out of natural and upcycled materials. They act as passive solar earth shelters designed to optimally utilize natural energy. Their basic Earthship principles developed with the aim for off-grid self-reliance and aesthetic as well as functional synergy with their natural surroundings.

In this post, we peek under the hood for a sense of what Earthship ownership could look like.

What Defines An Earthship Home?

Earthships are a form of earth shelter introduced by the New Mexico architect Michael Reynolds. As earth shelters, they are set into the ground, which features in their energy-saving dynamics as well as an overall natural appearance.

Reynold’s firm, Earthship Biotecture, has articulated six design principles that define the Earthship. These principles intend to give the Earthship its character as a self-contained, grid-independent unit:

  1. Water Catchment: Grid-supplied water is bypassed in favor of rain-harvested supply.
    Earthships trap and filter rainwater through potable surfaces and store them in cisterns. A Water Organizing Module dispenses the water at the required pressure.
  1. Waste Water Treatment: Greywater is treated and cleaned. It is recycled to feed the planting requirements of the Earthship and used for flushing. Sewage is not fed to the municipal system but treated onsite.
  1. Recycled Construction Material: The building materials used are sourced naturally or through recycling. The natural and recycled materials most commonly used are elaborated on under “Constructing an Earthship” below.
  1. Food Production: Earthships share design features with “Walipini” – Bolivian nurseries. Both are built below the frost line in a bid to access regular year-round ground thermal energy, conducive to growing crops. The solar orientation (see below) creates spaces that add to the Earthship’s character as a liveable nursery. The houses are built conducive to vermicomposting and permaculture.
  1. Solar Power: Many Earthships feature slanted equator-facing windows in order to absorb maximum solar energy. The walls are designed with air-spaced earthen walls that retain absorbed solar heat, distributing it inwards during the cool of the night.
    The fitting of solar panels and batteries is a core feature for providing energy to the Earthship.
  1. Heating and Cooling: The solar and geothermal structures mentioned above feature in the Earthship’s thermal regulation. This is designed to remove the need for fossil-derived heating and cooling systems.

Perhaps the signature feature of an Earthship concept is not its construction but its aesthetic. These buildings are designed to meld into their natural surroundings, and this is often done with stunning effect.

Earthships generally are single-story buildings that look as if they emerge naturally from below the ground. They tend to have stuccoed exteriors which, coupled with their New Mexican origin, evoke the look and feel of desert architecture.

Constructing An Earthship

The basic Earthship principles above should explain why the construction of Earthships starts with design. There are standard templates to choose from, and they are widely variable and easily adaptable to any homeowners’ preferences.

What Construction Materials Are Earthships Made Of?

As the name suggests, the main construction material is earth. However, that earth is usually turned into a rammed earth brick either by turning it into compressed earth blocks or by using repurposed materials Earthships incorporate into their design.

Here are some of the most common Earthship construction materials:

Tire Walls

External walls are made by compacting earth with sledgehammers inside unmodified rubber tires. These rubber “bricks” are stacked to form walls, which have the following features:

Can And Bottle Brick Walls

can and bottle walls in an earthship home

Can walls are built by compacting earth into recycled or discarded aluminum cans. These can be set in concrete, just as regular bricks, and are used to make strong walls and partitions.

Using glass bottles, mason jars, and containers like jugs, the same construction style may be used, obtaining a stained-glass look on the wall.

Rammed Earth and Compressed Earth Blocks

Approximately one-quarter of the world’s population have homes made of earth, however, these are mostly in the developing world, and the concept seems foreign here in the west. But with modern technology and machinery, rammed earth walls and compressed earth blocks can be not only cost-effective but can also be gorgeous!

The process is simple, dampening and then compressing earth (either with or without concrete mixed in) into forms.

Check out this home tour in Ontario, Canada to see one way of doing building a rammed earth home and also to see just how beautiful a the result can be:

Wood

Wood is often used for framing the interior walls, although this is done with caution as forests are at-risk resources and trees take a long time to grow. Wood is not as hardy as earth and can be brittle and decay with exposure to the elements.

Insulation

Earthship Bioculture calls for all buildings to use a combination of thermal transfer and insulation in order to affect temperature regulation. The thermal transfer involves materials of different temperatures transferring heat to obtain an average temperature.

Materials for insulation are:

How Are Earthships Designed?

The steps in Earthship design are as follows:

  1. Survey the land.
    • Track the movement of the winter sun.
    • Get a catalog of naturally available materials.
  2. Select a design template that fits the specific requirements of the homeowner.
  3. Get a design consultant to discuss the implementation. Earthships have particular design constraints and thermal sensitivities that need expert advice to resolve.
  4. Obtain permissions. Many jurisdictions do not allow the building of earthships. The specific final design needs to be cleared to ensure compliance with municipal ordnances.

Can You Hire Someone To Build An Earthship?

Earthship Biotecture is the leading designer and builder of Earthships. You can get help from Earthship Biotecture to guide you through the planning and permitting phases of Earthship construction.

You can also purchase construction plans from the Earthship Biotecture website that you can then use to find a builder.

The further away you get from New Mexico, the harder it is to find builders with the knowledge of the design principles, thermoregulation, and water reticulation systems involved. With that said Earthship homes are found globally.

The Financial Side Of The Earthship

One of the advantages of Earthships is that they take you off-grid. Recycled materials are cheaper than new stock. But there are costs.

Construction Costs Of An Earthship

The core components that add to the cost of an Earthship are:

These put construction costs for a modest Earthship within the range of a similar-sized conventional home.

Maintenance Costs Of An Earthship

Ongoing costs are largely limited to heating, water catchment, and sewage systems. The robustness of the architecture limits costs associated with wear.

Financing An Earthship

Earthships are hard to finance through conventional means. Some of the barriers include:

They have a limited resale market, as Earthship living does not appeal to a majority of home buyers. This reduces their value as collateral.

There is no secondary market, making their fair value hard to appraise.

If you live in the USA, the materials used are not on the HUD-approved list, placing 203(k) rehab loans out of contention, according to Realtor.com. They suggest that the best way to finance an Earthship home in the US is is to work with a local bank that knows you, understands Earthships, and is in an area where other Earthships have sold.

Another source of partial financing is green bonds. Lenders like Fannie Mae are offering these mortgage instruments for sustainable buildings. Green bonds can be an increasingly reliable source of mortgage finance for Earthships, coming off a low base at 1% of total bond issuance, on the back of strong demand for decarbonization.

Earthship Home Pros And Cons

Some of the factors to weigh include:

Advantages Of Earthships

Lifestyle: Earthships provide a way to live a sustainable life.

Habitat: Some desert locales are not conducive to conventional homes, as they lack the suburban grid infrastructure.

Cost: Barring labor, Earthships are made of inflation-resistant materials. The structures have low maintenance overheads.

Thermoregulation: Having access to regulated weather is vital in areas with extreme weather.

Aesthetics: To many people (this author included), Earthships are inherently beautiful homes.

Disadvantages Of Earthships

Non-Uniqueness: The thermoregulatory benefits of Earthships can be obtained more easily by retrofitting conventional buildings with geothermal and solar.

Financing and Regulation: The homes are difficult to finance, and in many places, impossible to get building approval as they violate building codes.

Grid Substitution: The reliance on propane to power water-heating and reticulation systems dilutes the off-grid promise. Some owners have complained that they’ve replaced utility bills with collateral expenses.

Habitat: Earthships have not proved their resilience in cold, snowy climates, where a weak winter sun and prolonged freeze overwhelm the solar thermal base. There are instances of these buildings being literally snowed under.

Skill: Outside of New Mexico, getting an Earthship designer with sufficient local knowledge to modify the known designs is hard.

Conclusion

Earthships are based on a strong moral argument about living our responsibility to the planet. This argument – as well as the patent fun of earth shelters – has drawn the interest of a small global community. But the barriers look like a long-term block on the mainstreaming of the idea.

thewriteDuffy

April is a writer, author, and online marketer with 15 years of experience writing for newspapers and magazines, building online authority websites, and publishing books. She has a diploma in journalism and a post-graduate diploma in book and magazine publishing.