Earthship Guide

Global Model Earthship, Taos, New Mexico. Photo: Biodiesel33 / Wikimedia Commons (CC BY-SA 3.0)

The Earthship is one of the more genuinely strange things to happen in American architecture over the last fifty years — and strange in a good way. Conceived by architect Michael Reynolds in the early 1970s outside Taos, New Mexico, these off-grid homes are built largely from automobile tires packed with earth, glass bottles, aluminum cans, and whatever else industrial society has discarded. They harvest their own water, generate their own electricity, treat their own waste, and grow food year-round in an interior greenhouse. They are, in Reynolds' own words, "living breathing cells" that take care of their inhabitants entirely through encounter with natural phenomena — sun, rain, gravity, wind.

It is worth being clear about what Earthships are and are not. They do not belong to any architectural tradition in the formal sense. Reynolds came up through a radically different frame of reference than the canonical modernists — his lineage runs through Buckminster Fuller's resource-efficiency thinking, the counterculture self-sufficiency movement of the 1960s and 70s, and forty years of trial and error on the high desert Mesa. There is no spatial composition here in the sense an architect trained in the classical tradition would recognize, no studied relationship between form and site beyond the practical logic of the berm. What Earthships lack in aesthetic ambition, however, they more than compensate for in systemic ingenuity. They stand entirely on their own terms, and those terms deserve serious attention.

---

How It Works

A detailed walkthrough of Earthship construction and systems — tire pounding, glass brick fabrication, the four-stage water cycle, gray water botanical cells, photovoltaic energy, and passive thermal regulation.

Six Principles

Every Earthship — from the simplest survival hut to what Reynolds calls the "global model," the fully-appointed version he describes as the BMW of Earthships — is organized around six integrated principles. They are not stylistic preferences. They are load-bearing ideas, each solving a specific dependency on external infrastructure.

01 — SOLAR ORIENTATION, THERMAL MASS & PASSIVE TEMPERATURE REGULATION. Every Earthship is oriented due south — this is not a preference but a precondition. The entire passive thermal system depends on it. The long south face of the building is glazed floor to ceiling, angled to be perpendicular to the low winter sun so that sunlight penetrates deep into the interior through the day. In summer, the sun is higher in the sky and largely misses the interior, striking the glass at a steep angle rather than shooting through it. This single geometric fact — the difference between winter and summer sun angles — does most of the climate control work without any mechanical assistance whatsoever. The greenhouse that runs the full length of the south face is isolated from the main living space in the newer global model designs; in winter the connecting doors are opened to admit solar-heated air, in summer they are closed to keep the heat contained in the greenhouse and away from the living quarters. This refinement alone is what pushed interior temperatures from an acceptable 64–74°F range in earlier designs to a flat 71°F year-round in the current generation. The thermal mass behind the glass locks in those gains. Automobile tires rammed solid with 300 to 400 pounds of compacted earth are stacked into the side and rear walls and bermed into the hillside. These walls act as a thermal battery: absorbing solar heat through the day and radiating it back into the living space through the night. The buried earth of the berm holds a steady ground temperature — like a cave — that further dampens any temperature swings. The new global model achieves 71°F year-round with no external heating or cooling system of any kind.

02 — SOLAR & WIND ELECTRICITY. Photovoltaic panels convert sunlight into DC current, which is stored in a battery bank and managed through a power organizing module that distributes energy to appliances, prevents overcharging, and protects against battery drain. Wind turbines operate on the same principle, spinning a rotor that drives a generator through electromagnetic induction. Together these systems provide sufficient electricity for a full household — lighting, refrigeration, electronics — entirely off-grid. The most power-hungry appliance is the refrigerator; Earthships use purpose-built super-insulated DC refrigerators that minimize draw on the battery bank.

03 — WATER HARVESTING. Rain and snowmelt are captured from the roof, channeled through gravel filters and silt catchers, and fed by gravity into cisterns — the global model holds up to 6,800 gallons. From there, a water organizing module pumps and filters the supply into a pressurized system for household use. The ingenuity of the Earthship water cycle lies in what happens next: the water is used not once but four times. It is first used for washing and bathing. The resulting gray water passes through a worm-box digestor and then through an interior botanical cell — a built soil ecosystem planted with food-producing species — which filters the water while irrigating the garden. Treated gray water is then pumped into the toilets for flushing. After flushing, the now-black water passes to a septic tank and finally to an exterior rubber-lined botanical cell, where it feeds landscaping plants. Nothing leaves the site. The United Nations has projected that half the global population will face water scarcity by 2025; the Earthship answers that projection with a closed-loop system that would function on less than nine inches of annual rainfall.

04 — CONTAINED SEWAGE TREATMENT. The exterior blackwater planter — a rubber-lined pit typically 20 by 40 feet and six feet deep, filled with gravel — is one of the most underappreciated elements in the Earthship system. Black water flows from the septic tank into this cell, where plant root systems absorb it from four feet underground. The result is rich, perpetually irrigated landscaping in the middle of the high desert, with no smell, no maintenance, no leaching into groundwater, and no discharge. Reynolds has argued, reasonably, that there is no technical reason every building on earth could not incorporate a similar cell.

05 — BUILDING WITH RECYCLED & NATURAL MATERIALS. Tires are the primary structural element — free, ubiquitous, and when rammed with earth, essentially indestructible. Aluminum cans are used as matrix fill within cement walls, reducing the total volume of concrete required without sacrificing structural integrity. Glass bottles, cut in half and taped back-to-back, become translucent bricks that admit light while providing insulation. The county of Taos supplies the Earthship community with bottles, tires, and mulch — the waste stream becomes the building supply chain. An Earthship requires approximately 800 to 900 tires per home.

06 — FOOD PRODUCTION. The interior greenhouse runs the full length of the building's south face, providing sunlight, temperature protection, automatic irrigation through the gray water system, and nutrients from filtered wastewater. Plants growing in this space — figs, bananas, tomatoes, herbs, papayas at 7,000 feet elevation — require no external watering once their roots lock into the gray water system. Experimental designs have incorporated tilapia ponds and aquaponic systems. The food production principle is, by Reynolds' own account, the one still being most actively developed.

"Each building is a living breathing cell that is getting everything that its inhabitants need from an encounter with the natural phenomena of the planet — the sun, the rain, the gravity, the wind."

— Michael Reynolds

---

The Refuge: Economy Model

The six principles described above play out differently depending on which point in the Earthship range you are looking at. The global model — the fully-appointed, 71°F year-round home with the lush interior greenhouse — is the benchmark Reynolds has spent fifty years developing. But it is not the only product Earthship Biotecture now builds. In 2024, Reynolds completed the first official Refuge: a 1,600 square foot, two-bedroom, two-bathroom home designed around the same six principles at a fraction of the complexity and cost. Reynolds calls it the Model T of Earthships.

The Refuge strips the system to its essentials without compromising any of the core performance. Thermal regulation is handled by the standard south-facing glazed face and tire-and-earth rear wall, but cooling is augmented by a simple passive ventilation system that the global model does not require: 12- to 15-inch diameter tubes pass through the bermed north wall, drawing in air that loses its heat to the cooler earth as it travels through. In summer the tubes are open and transoms above the doors allow hot air to escape by natural convection — no mechanical assistance, no power draw. In winter the tubes are plugged. It is a refinement borrowed from the logic of the cave and the physics of the chimney, and it works.

The power system is equally compact: eight 400-watt photovoltaic panels feed a power organizing module with eight sealed maintenance-free batteries — enough for lights, a washing machine, refrigeration, and electronics. The cistern is homemade from tires with a metal roof rather than purchased plastic tanks; gravity feeds it directly into the water organizing module. The gray water botanical cells run the length of the south planter in each room, feeding figs, bananas, and herbs while cycling shower water back to flush the toilets. Every one of Reynolds' six points is present and operational. What the Refuge gives up in scale and finish, it returns in accessibility. This is the Earthship as a thing a person of ordinary means can actually build.

The Refuge: A Walkthrough

Michael Reynolds walks through the first completed Refuge — Earthship Biotecture's economy model — explaining all six systems in a finished 1,600 sq ft, two-bedroom home. Completed March 2024.

---

The Community at Taos

The Greater World Earthship Community sits on roughly 690 acres of high desert mesa twenty minutes outside Taos, New Mexico, at around 7,000 feet elevation. It began as an illegal subdivision — shut down by local authorities at the instigation of a lawyer in town — and has since grown to approximately 70 homes, with more under construction. During the 2008 financial crisis, when the rest of the building industry collapsed, Earthship Biotecture was one of the few operations still actively building. People took whatever savings they had and decided to get off the grid.

The State of New Mexico designated two acres of the property as an experimental zone — no permitting restrictions, no county oversight beyond occasional observation — a concession Reynolds won from the state legislature by simply asking. Within that zone, the Earthship Academy trains students in every technique: tire pounding, glass brick fabrication, can wall laying, water system plumbing, solar wiring. The county brings bottles, tires, and mulch. Students build the structures that become their own housing while they are there. It is an entirely self-referential educational model: the school building is the curriculum.

The community spans an enormous range of scale and finish. The simple survival Earthship is a stripped-down one-room structure with roll-out solar panels, black water tanks in the south window for solar water heating, and fifteen gallons of hot water by end of day — the minimum a person needs to live, Reynolds argues, in most climates on earth. The global model at the other end of the spectrum is a fully-appointed two-to-three bedroom home with adequate power for any standard American appliance load, stable year-round temperature without any fossil fuel input, and a lush interior greenhouse. A resident of the community reports paying $300 a year in utilities — $100 for propane for the cooking stove, $200 for an occasional water delivery in the driest years.

A tour of the Greater World Earthship Community west of Taos — from the survival hut to the fully-appointed global model, with Reynolds' collaborators discussing life off the grid.

---

An Honest Assessment

Earthships are not beautiful architecture in any conventional sense. The aesthetic is an honest byproduct of the process — the exposed tire walls, the bottle-brick patterns, the greenhouse jumble of vegetation and plumbing — rather than an intentional composition. Reynolds has never claimed otherwise. What he has consistently claimed is that they work, and on that count the evidence after fifty years of iteration is difficult to argue with.

The real barriers to wider adoption are practical rather than philosophical. Permitting outside communities like Taos remains the single largest obstacle — the systems are unconventional enough that county inspectors have no framework for evaluating them, and the tire walls in particular remain a sticking point in most jurisdictions despite no structural evidence of failure. Cost is the second barrier: a global model runs around $225 per square foot, comparable to conventional construction, but without a mortgage market willing to finance them, most buyers must pay cash or contribute significant sweat equity. The third is climate range — the passive solar and thermal mass strategy works extraordinarily well in the high desert Southwest and struggles in cloudy, low-sun, or extremely cold environments without meaningful design modification.

None of those barriers diminish the underlying proposition. Fossil fuels supply approximately 90% of the world's commercial energy. Municipal water systems are energy-intensive, vulnerable, and — in an increasing number of regions — unreliable. Sewage infrastructure in most of the developing world does not exist in functional form. Food production depends on chemical inputs, transportation networks, and water supplies all facing serious pressure. The Earthship addresses all five of these simultaneously with a building that costs roughly the same as a conventional house and, once built, costs almost nothing to operate. That is a genuinely significant achievement, regardless of what it looks like.

"Everybody wants the new phone. Everyone wants the new iPod or the new car. Why can't they want the next house?"

— Michael Reynolds

---

Related

• Earthbag Eco Homes