Earthships: An Off-Grid Habitat

Earthships are a type of passive solar home made of natural and recycled materials, primarily to work autonomously – generally made of earth-filled tires, using thermal mass construction to regulate indoor temperature. Earthships also have their own special natural ventilation systems and are generally off-the-grid homes, minimizing the reliance on public utilities and fossil fuels. The Earthships are built to utilize the available local resources, especially energy from the sun. 

In this article, you will get to know what are Earthships and how they benefit our planet.

What is an Earthship?

An Earthship is the most sustainable living structure that was developed and has been under advancements by Architect Michael Reynolds for the past four decades. Earthships are built from salvaged waster materials that can be easily sourced- beer cans, old tires, and bottles are a key ingredient to the construction process. Architect Michael Reynolds created the first Earthship in the 1970s, combining the two main issues of rubbish piles and lack of affordable housing.

Earthships don’t require central heating or air conditioning, so the resources needed are kept to a minimum. Their self-sustainability is because of the main areas that drop off the grid, including:

• Food production
• Electricity
• Temperature regulation
• Water
• Sewage treatment
• Housing

Being widely and relatively self-dependent, Earthships produce their own food and electricity, harvest natural water and handle the sewage. More research is being developed to make a perfect off-grid biostructure with zero emissions.

Construction+ Design of an Earthship:

From the first Earthship home in New Mexico, Earthships have come a long way, where Michael Reynolds came up with the concept. He wanted an Earthship to be built out of affordable and readily available materials, to be easily constructible for people who have n building skills and produce energy from natural sources. A v-shaped Earthship is more preferred due to its easier to collect water due to slant and temperature regulations.

1. Choosing and Excavating the site: One of the important factors to consider while making an Earthship is angle and the direction of the sun. Excavating soil from the chosen site by digging about five or more feet into the ground, as the depth of the foundation will depend on the climatic conditions of your chosen location, climate, the deeper the foundation.
2. Choosing the right construction materials: While choosing materials its important to consider the local availability with the budget as the materials shall cost as little as possible. In wet climates, roofing materials that prevent leakage shall be considered, materials ideal for temperature regulations are also important.
3. Making the foundation and Outer walls: At some locations, tires are used as the fundamental building materials and it starts with laying out tires.
4. Making the interior walls: After the outside walls are made, interior walls should be made depending on the number of rooms needed. For stronger walls, stacked tires can be filled with earth.
5. Roofing: Truss can be erected first with two or more metal poles or wooden beams to form a triangle or a series of triangles. Roofing materials like dried grass, wooden beams or tin cans can be used for effective roofing.
6. Water Production in an Earthship: Earthships are made to catch all the water around them from rain or snow. the slanted room makes sure water is directed towards the back of the house where it is directed into a cistern by a gutter with a sieve to catch any solid particles in water.

Design Principles:

Earthships can be defined by six different design principles:

Building with Natural and Repurposed Materials:

1. Earthships incorporate natural and reclaimed materials in the construction.
2. Tires are used as a perfect alternative for rammed-earth bricks.
3. Materials like cans, bottles, tires are also used and act as a stand-out feature for many Earthships.
4. The interior walls are packed between the tires and plastered with adobe mud for stability and strength.
5. Adobe mud is also used for floors, and reclaimed wood and metals are also used in the structure.

Solar Heating and Cooling:

1. The most fundamental Earthships is the one that heats and cool themselves without electric heat, burning fossil fuels and wood.
2. Earthships are capable of maintaining a comfortable temperature without additional fuels due to their thermal and solar gain.
3. The tires used as a structural material are wide enough to eliminate the need for concrete foundation.
4. The densely packed walls, considered to be self-supporting monolithic walls store temperature because of their solidity imbues them with the quality of thermal mass.
5. In the evening or night, when the air temperature drops below the stored wall temperature, heat naturally released into space.
6. The enhancement of cooling with natural ventilation through buried cooling tubes and operable vent boxes.

Solar and Wind Electricity:

1. Every Earthship has it’s own renewable ‘power plant’ with photovoltaic panels, batteries, charge controller and inverter.
2. Supper efficient lighting, pumps, and refrigeration that helps in lowering the load, as does the lack of any need for electric heat or air conditioning.
3. Earthship’s electrical needs are about 25 percent of that of a conventional home.

Water Harvesting:

1. Earthships collect all the water needs from rain and snowmelt on the roof, storing this water in cisterns. Each inch of rain collected from a square foot of roof equals 2/3 of a gallon of water.
2. The water from the cistern feeds a pump and filter system that cleans the water and sends it to the solar hot water heater and also to the pressure tanks.
3. The collected water is then used for bathing, washing dishes, and laundry.

Contained Sewage Treatment:

1. The used gray water flows to interior botanical cells, where plants use up and treat the water until it’s clean enough to be collected in a well at the ends of the planter and pumped to the toilet tank for flushing.
2. The toilet water then goes to a conventional septic tank, which overflows into exterior landscaping plants.
3. Each and every drop of water that lands on an Earthship roof are used four times, so homes subsist and even thrive without taking water from the ground or municipal sources.

Food Production:

1. Organic food production is the most recent design principle added to the Earthship concepts.
2. Earthship Biotecture employs a plant specialist who has experimented with various plants for interior gray-water botanical cells.

Houses sheltered by earth have a higher chance of survival in worst-case scenarios, as the earth-based constructions are non-flammable, resistant to harsh climates, etc. A typical Earthship design has double-glazed windows to the north to let the winter sun, pushed up to roof level, protect the south, east, and west walls. The north-facing double-glazed windows are only part of a building that needs some protection.

You don’t need to be a hippie to benefit from being off-grid, all you need is feel good about doing your bit for the planet. Definitely, the use of ideas from Earthships, with wetlands for greywater harvesting, recycled bottle and can walls, good passive design techniques will benefit your design and Earthships for that matter are really wonderful to start with.

To know more about Architecture Technology, Stay Tuned. 

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