How sustainable housing innovation in the American southwest might be a window into future design principles of remote and efficient living.
As an early teenager, I consumed science fiction with intense voracity. By far, the thing that interested me most was the possibility of a self sustaining system that could support life. Whether it be some sort of sealed terrarium, the inside of a hollowed out asteroid, or a high tech escape pod, the elegance of circular systems has never failed to satisfy my imagination. This appreciation is a large part of what led me to study civil and environmental engineering, and is still a driving force behind my academic pursuits today.
Recently my curiosity led me to stumble upon a type of buildings called Earthships, which rather surprisingly share many of the same satisfying characteristics of enclosed environments. Although not practical in every location, they address many key problems with the unsustainable nature of today’s human-built environments, and because of their decentralized and grassroots nature, are a sort of bottom-up parallel to the trend of big-tech green installations, which you can read more about here.
So what is an Earthship home?
Earthships are custom built, off-grid capable homes that achieve ultra high levels of energy efficiency, built largely out of recycled or re-used materials. The style was pioneered in the 1970s by Michael Reynolds, a draft-dodging hippie who moved to the southwest from Ohio and was inspired by the local adobe style architecture.
Since he started building Earthships in Taos New Mexico, over 300 of these unique and beautiful structures have popped up around the world. Here’s a particularly beautiful one in Taos, a hotspot for the style, with over 70 Earthships forming a neighborhood. I especially like the copper-patina-esque coloring.
Beyond their aesthetics, Earthships are a delightful fusion of a few key functionalities, namely:
Passive Heating and Cooling Systems
Sustainable and Self Sufficient Energy Generation
Recycled Materials and Sustainable Construction
Lets break down how these structures provide these functionalities.
Passive heating and cooling is accomplished by taking advantage of air convection and something called thermal mass construction to create wind drafts that cool the house in the summer and store heat that is then radiated to the house at night.
In the image below, you can see how in summer, the wind shaft at the back is open, which allows air to be sucked into the home by the pressure differential caused by the vented front windows. This air is cooled by the mass of the rear mound and tire wall, and also creates a pleasant airflow in the home. In the winter, the low angle of the sun allows the home to capture much more natural light, the wall of tires at the back of the home soaks up and retains this heat, and radiate it later. During the cool night, the mass of the earth and tire wall lets some of the captured heat back out, maintaining comfortable temperature for the resident.
Earthships also rely heavily on water use and retention, with most of them sourcing their water from the rain. To keep water costs low they use intensive greywater recycling systems, sometimes opting to forgo the flush and use only composting toilets. By cutting toilets out of the equation, some Earthships can even re-use greywater after minimal treatment, before routing it to botanical cells in the front sunroom where it is used to nourish fruits and vegetables.
Sustainable Energy generation is pretty simple, Earthships generally use solar and wind energy, with an interesting array of miniature wind turbines like the one pictured below. Energy is stored for off-hours use in battery arrays.
I think it would be interesting to see a cluster of Earthships use a small scale vortex style hydro-power solution (example below), which don’t significantly disrupt river flow, can be run in series down a riverbank, and are even fish friendly.
With this diverse set of renewable energy sources, Earthships are well suited for off grid living, especially if the owner were to overbuild generation and storage capacity in order to allow any one source to provide enough to power the home in times of scarcity.
Earthships also make use of many recycled and reused materials in their construction, with the rear retaining walls and wall bases for the main structure being made mostly from tires packed with earth and covered in adobe plaster. They also make use of glass bottles in a mosaic fashion to let in diffuse light and tin cans to reflect the harsh sun from the building.
Because Earthships are made largely from recycled and repurposed materials, and are constructed by pseudo-Amish style teams of laborers, they account for significantly less embodied carbon than a conventional building would, due to the lower emissions inputs involved in the manufacturing and construction processes as compared to new construction.
In the United Sates, household climate control systems account for just over half of our energy expenditures, with this percentage climbing drastically in the country’s most extreme environments. The same trend is true for water, with around 30 percent of the average household’s water being devoted to outdoor use (read lawns), topping out at around 50 percent in the nations hottest climates. The energy generation situation in the U.S. is also concerning, with only around 11% of the nations energy being generated by renewables as shown in the figure below.
Earthships take a grassroots approach to addressing these and many other problems that loom over our world today. Too often we expect solutions to come down from on high, and more often than not the solutions that work best are ones people take initiative to do for themselves.
Density is great, but it’s not for everyone. If we can use solutions like Earthships to make living remotely more appealing and better for the environment, I’m all for it. Earthships are not a solution that can house everyone on earth, but they can teach us some valuable lessons about the systems we might eventually need to do that, and more.
-Connor, Of All Trades
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If you’d like to learn more about Earthships here are some links and resources that inspired me to learn more!