What can you do with old tires and dirt? You’ve probably seen some tire flower planters or tire obstacle courses for kids or even DIY chairs. How about a house? Sounds silly? Well, discarded tires filled with dirt are the main building material for “Earthship” homes. If you think it’s just another hard-to-replicate, ingenious, and insane DIY project of a handy environmentalist, you’re wrong. The Earthship is not a project, it is the concept pioneered by architect Michael Raynolds.
There are more than 3,000 Earthship homes worldwide. And the concept covers much more than just building houses with recycled materials. The basic idea is to use recycled and local materials to build a sustainable, off grid house. And it should be feasible for people with little building knowledge. This exciting concept originated in the early 1970s and it’s still going strong. So, let’s take a closer look at it.
What Exactly is an Earthship?
An Earthship is a type of passive solar earth house. As a young architect, Michael Raynolds developed the concept in the 1970s with three basic ideas on his mind. He wanted to create homes using sustainable architecture. It means using anything you have at your disposal from old tires to used soda cans.
Off grid and self-sufficient home was the second pillar of the concept. The idea was to rely on natural sources of energy and be completely or almost completely independent from public utilities. Finally, average Joe and plain Jane should be able to build it. So, an Earthship is a low-impact, relatively low-cost, sustainable home that almost anyone can build! It sounds almost like a fairy tale, but it lives on 40 years after its inception. In all honesty, it’s not really that simple, but it’s feasible and viable. After all, there are 3,000 proofs for that.
It is easy to talk and wish for self-sufficiency and sustainability. Achieving it is a whole different story. Michael Raynolds tried to solve this through 6 basic principles or human needs.
- Shelter. Constructing and building homes with recycled and locally available materials allows for lower cost and lower carbon and waste footprints.
- Power. Creating an off-grid home requires independent power sources. Earthship uses solar and wind power to provide all electricity you need.
- Heating and cooling. Solar panels and wind generators usually can’t provide enough energy for heating and cooling. However, a clever design relies on passive solar heating and cooling as well as on thermal mass provided by thick tire walls.
- Water. Harvesting rain and condensation can provide enough water for all of your needs. This is possible because of great design and water management. Water is used three or four times by virtue of filtering systems and smart design.
- Sewage. It is contained and treated in order to avoid a public sewage system or putting harmful waste into the ground.
- Food. Commonly, small greenhouses are used to allow in-home food production. These spaces also help with temperature regulation.
How to Build an Earthship
While the whole idea sounds fantastic and you don’t have to be an engineer, architect, or construction worker to build it, it’s still a daunting mission. You can do it, but you should consult the experts and prepare thoroughly.
Choose Your Location
For starters, each location comes with specific challenges, so there are no rules and formulas that apply to all Earthship homes. You need to find a location that will allow you to make the best of it. The idea is to take advantage of your environment as much as possible. So, think about climate, rainfall, positioning, gravity, wind, the incline of the terrain, and available materials.
Keep in mind that the original concept was developed for a semi-arid, high altitude environment of Taos, New Mexico. The more different the climate, the more alterations and adaptations you’ll need.
Get Some Knowledge
You can stick to some basic designs, but in order to be prepared, you need to learn a few things to avoid mistakes. Read a few books or take some courses about passive solar design. Angles, glazing, shading, thermal mass, and thermal insulation play an important part in your design and every mistake will reduce your home’s capability of collecting, storing, and distributing solar energy.
While your basic material is junk and earth, it can still be challenging to find and transport these materials. For example, a typical Earthship contains 500 to 1,500 old tires depending on the size of the Earthship. You can also use soda cans for inner walls, but still, you need a lot of them. And that’s not all you need. You will probably use cement and concrete to support tire and earth walls. Alternatively, you can use adobe, it is my favorite material, even though it’s susceptible to earthquake damage. So, if you use adobe you need to reinforce it.
Sand, stones, timber, glass, and earth bags can also be useful.
Design and Construction
A simple horseshoe shape is the most common in Earthships. It doesn’t require a high skill level while 90 degrees angle is pretty difficult to create with rammed tires. The positioning of the horseshoe opening is critical to maximizing light and solar heat in the winter. Walls should be thick and dense to provide thermal mass and regulate the temperature inside the house. Tires packed with earth are great for this purpose but you will have to put a lot of elbow grease into it. First, place the tire and then fill it and ram it. Rammed tires can weigh 200 to 300 hundred pounds, so they’re not really portable.
As for the roof, you’ll need wooden beams to support the structure. If you’re inexperienced you should hire carpenters to frame windows and build the roof.
The last stage is plastering the walls. You can use mud plaster and shape it to improve both visual and insulating effects. Now, it’s time to install solar panels and possibly windmills.
At the end of the day, construction and design are similar to any other passive solar home. The south side is covered with lots of glass, east and west walls should provide thermal mass and the earth-bermed north side offers additional protection.
This is my favorite part of an Earthship. Water management is just brilliant. With a couple of clever solutions, Earthship’s water system allows you to use much smaller amounts of water.
It all starts with the roof. Catchment funnels and design make sure to collect all of the water. The collected water is purified and filtered so it can be used for drinking, bathing, or washing dishes. After that, it becomes “grey water”. It goes through another cleaning cycle through grease and particle filters.
Feeding this water into the interior botanical cell is another ingenious solution. Plants and bacteria filter and oxygenate the water. It comes out clean and odorless, although it’s not drinkable.
Now, you can use this water to flush toilets. In conventional homes, an average person spends between 60 and 100 gallons of water per day. Earthship water management reduces the amount of spent water to 20 gallons per day without sacrificing comfort.
While many parts of the building process can be slightly altered, I’d follow water management principles to the letter.
This is actually the last step in water management. After using the water in the toilets it becomes black water. It is not recommended to use this water for edible plants. However, it can be used in external botanical cells. But, first, you need to build a conventional septic tank. Well, sort of. Earthships have improved septic tanks that are south glazed and solar heated. This helps to accelerate and intensify anaerobic processes in the tank.
Finally, you should build two lines out of the tank. One will go to the leach drain and another one to the exterior botanical cell. Leach fields or leach drains contain microbial ecosystems, silt, clay, and gravel. Altogether, they act as a biofilter and prevent contamination of water wells.
That’s it! You’ve got it all covered, from renewable energy, and passive heating/cooling to collecting water and waste treatment.
Is There a Downside?
While this building system is very successful and widespread, it’s only fair to mention the downside as well. The first of Earthship homes project in New Mexico was a huge success. It was a springboard that propelled the concept and made it recognized, worldwide.
However, cold and humid climates turned out to be tough nuts to crack. Several Earthships in Canada faced problems with inadequate heating. Also, in some very humid areas, there were problems with mold. Canadians solved their problems using wood stoves, propane heaters, and generators as a backup. New models of Earthship, however, feature improved insulation and better ventilation systems to prevent mold growth.
So, it’s not always perfect, but I’m still a strong proponent of sustainable architecture. After all, even these “flawed” Earthships didn’t turn into a disaster. While they are not completely independent and sustainable, they are close enough.
Obviously, I am a big fan of Earthships and I think everyone should support these kinds of projects. Whether you’re an environmentalist or a prepper who needs a sustainable bug out location, or you just dream of living off the grid, these homes provide all you need. There’s a lot of ingenuity but no magic behind it. It shows that if we try to live in harmony with the earth, we can use it without devastating it. Life in an Earthship can be sustainable and self-sufficient without sacrificing modern amenities. What else could you ask for?