Earthship Homes

  • Situated in a semi-rural location about 40 minutes from the bustling city of Adelaide in Australia, the Earthship Ironbank is a quaint bed and breakfast that costs around £137 ($180) per night.
  • Completely self-sufficient, Australia’s first Earthship is designed for two people and features an open-plan layout with far-reaching views across the countryside beyond.
  • The property has its own indoor garden to grow vegetables and fruits

Images via LoveProperty

Earthship homes aim to meet basic human needs (shelter, heat, food, water, etc.) through self-sufficiency and sustainability. 

Architect Michael Reynolds pioneered Earthship homes in the 1970s. His idea of Earthsip homes came from realizing the  amount of rubbish piling up and the lack of affordable housing could be simultaenously addressed.

Principles of Earthship Homes

Repurposed Materials
Image via taos.org
Home-Grown Produce
Sewage Treatment
Solar Panel
Earthship home has its own renewable “power plant” with PV panels, batteries, charge controller, and inverter. An earthship’s electricity use is 25% of that of a conventional home
Water Harvesting
Earthships collects water from rain and snowmelt on the roof, storing it in cisterns which feed a pump and filter system which, in turn, cleans the water and sends it to a solar water heater and pressure tank. From there, water is used for bathing, washing dishes, and laundry. Because every drop of water collected is used four times, earthships can subsist without taking water from the ground or municipal sources.
Shelter


Image via The Boho Guide

Earthships have their name because they operate autonomously from outside sources, just as ships do when they are sailing the open seas. These 6 basic principles that guide Earthship homes design.


Click on each principle to read more about how these components of Earthship homes function and how to install them. 
 

Costs and Other Considerations for Earthships

Generally, Earthships can cost between $20,000 to $500,000, depending on the size of your home, amount of labor you need and other necessary inclusions.


If you want to build one yourself, Earthship Biotecture offers a one-month training program for $2,500. Read more about costs here


 

Click here to read some things to consider for an Earthship home as well as advatanges and disadvantages. 
 

Choosing a Location

Earthships are not suitable for all climates, since wet conditions may create internal mold issues. If you live someplace with everchanging weather, a backup power sources for fall and winter may be needed when there is not enough sun for your solar energy panels. 

Straw Bale Homes

Image via SimpleConstruct

Straw Bale homes use straw waste as insultation material. This home type reduces home building costs and provides excellent insulation and through  eco-friendly, biodegradable straw material. 



These houses were a temporary invention among the 19th-century farmers who relied on wheat crop waste as the only construction material. However, straw bale houses have been tested and confirmed to be comfortable, warm, and durable giving them recent popularity. 

Click here to access a comprehensive Guide by on building a straw bale home. 

Benefits of Straw Bale Homes

Energy Efficiency
The only energy needed to make a straw bale is in the bailing process and the transportation to the worksite. Other insulation materials, such as fiberglass, require a substantial amount of energy to produce.

Image via Julia Furlong

100% Biodegradable
Straw bales are 100% biodegradable—when the time comes. At some point, all structures will eventually be replaced. When the time comes, the straw bales can be plowed back into the earth. Fiberglass, on the other hand, becomes a disposal problem
Readily Available, Low Impact Materials
Straw bales come from agricultural waste products. Once the rice, barley, rye, oats, or wheat has been harvested, the stalks can be baled giving the straw a new life. The bales are renewable each year, and their harvest requires little effort. The process of harvesting and construction further presents little harm to the environment. Since they are easy and light to transport, you are likely to save on associated fuel and transportation costs
Great Insulation
Straw bale houses are known for their excellent insulation. The quality of insulation is dependent on several factors such as building design, type and quality of plaster used, the mesh manner between the roof insulation and the bales, and how you stack your bales. If a straw bale house is built correctly, it provides a 40 to 60 R-value. Choose thicker bales for higher R-values.

Image via Julia Furlong

Fire Retardant
Compared to timber frame homes, straw bale houses have been shown to be more fire retardant. Numerous studies have been conducted to test the flammability of straw bale houses. Fire resistance is achieved because the bales are tightly packed. Oxygen barely enters between the straws thereby limiting any chance of triggering combustion.

Image via Medium

How it Works

Straw Bale homes can last over 100 years if properly built and maintained. With insulation values of R-30 to R-35 or more, straw bale offers great insulation and comfort for your home.  

Straw bale walls are at least eighteen inches thick, giving your home extra aesthetic value to the home since thick walls are expensive to achieve with traditional construction. The thicker the bale, the better the R-value.

 

 

What weather is best for straw bale homes? 

If your straw bale home is constructed properly, it won’t rot since the porous texture allows air circulation. If you live in an especially humid area, lime-based plasters work best to keep moisture at bay. However, these homes are not recommended for areas with extreme rain and moisture.

 

Click here to access a comprehensive Guide by on building a straw bale home. 

What Else Should I Consider?
 

Click here to learn more about design criteria and considerations. Here are some tips to keep in mind: 

  • If your local building codes do not have regulations for building with straw bale, you may face planning challenges. This might require working with local engineers and architects who are familiar with natural materials to help in gaining this approval.

  • Due to the thickness of straw bale, most of your square footage will be taken up by the wall thickness.

  • If straw bale material is not locally available, you may have additional shipping costs and the additional challenge of ensuring they arrive intact 

Straw bales are a natural and renewable material with a significantly lower environmental footprint than most other types of insulation materials
 

Adobe Homes

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Images via Architectural Digest. Brittany Ambridge

Adobe homes can be traced back to 8300 B.C. , making them the oldest continually inhabited structures in the world. 

Earth-based and local materials, such as mud, clay, and straw, make the bricks used to construct the walls of traditional Adobe homes. These homes can offer fireproof, biodegradable structures that are long lasting and built with low-energy. They have thick, round-edged walls with small, square windows that reflect the look of traditional Indian Pueblos.

What Benefits do Adobe Homes Offer?

  • Eco-Friendy Materials

    Compared to current building materials, adobe bricks produce minimal net waste and zero hazardous waste. In the entire cycle of an adobe house’s life, the footprint on the environment is small.

  • Lower Building Costs

    When materials are harvested from the local environment, transportation energy and material costs decreases significantly

  • Low Footprint

    By avoiding using modern building materials that require high energy to produce, adobe bricks have a much lower carbon footprint and use local materials and natural heat and solidify the structure

  • Energy Savings

    In climates typified by hot days and cool nights, the high thermal mass of adobe mediates the high and low temperatures of the day, moderating the temperature of the living space. Adobe’s thermal mass makes it a very energy efficient material. During the colder winter months, the clay and sand compound absorbs energy from the sun, radiating heat throughout. During the warmer months, this material stores the leftover coolness from the previous night.

  • Unique Designs

    Abode homes can be customized and designed to your needs and preferred aesthetic. Exposed wooden beams and unique window shapes add warmth and color to your home.

Costs and Other Considerations

 Costs can range from $55-85 per square foot, using salvaged and saved materials, a simple design and a few custom touches.

Adobe homes are some of the cheapest and most eco-friendly earth homes to build due to reduced costs of locally sourced materials. The amount of energy required to make one adobe brick is 30 times less than the energy required to produce one kiln-baked conventional brick since they are solidified with outdoor heat.


 

Weather and Climate

Given the environment factors needed to efficiently produce adobe bricks, adobe buildings are primarily confined to warm and dry places.

Limited regions in the world offer the conditions needed for adobe homes: prolonged periods of fairly hot and dry weather. Trying to rush the process to dry adobe bricks by setting them close to a fire will result in uneven  heating and cracking, while a slow drying time creates other structural issues. 

Adobe buildings are
not very common in places with cold winters since adobe walls lack the insulation needed when temperatures dip.

naturalhome_26.jpg

Rammed Earth Homes

Image via Dwell 

Rammed homes are made of damp soil or earth that is placed in formwork, and then compressed or rammed into a solid, dense wall.

Rammed earth construction almost disappeared with the development of reinforced concrete, but there has been a revival in interest because of its aesthetics and the environmental benefits they offer.

Image via Dwell 

How Does it Work?

Rammed earth homes are like building sand a castles without that having to flip the bucket. Instead, the form of the home is already in place with a plywood structure and if filled with earth materials to create the walls. 

A mix of soils is rammed into the structure, which is reinforced through structural engineering. When everything is packed tightly, the plywood structure is removed and leaves a solid, stable wall. Builders ram and repeat until the entire house is built.

Benefits and Challenges of Rammed Earth Homes

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Comfort
and
Eco-Friendliness

Rammed earth is non-toxic, non-polluting and ‘breathes’. This creates safer, more people-friendly buildings. It is very low in embodied energy, and extremely comfortable to live in.

Low Maintenance

Once they are built and sealed, they shouldn’t need any further attention for at least 10-20 years. Rammed earth walls are features that stand alone and don’t need finishing with plasterboard or render, inside or outside.

Manual Labor Costs

A wall system in a rammed earth home can cost about 30 percent to 50 percent more than a conventional wood-frame house due to manual labor, which means the entire home might cost about 5 percent to 15 percent more

Thermal Mass and
Climate Challenges

Rammed earth has high thermal mass but low insulation. This makes rammed homes good for desert like environments but challenging in places with prolonged cold weather and rain. This factors might require additional insulation, as well as a larger roof, so that the overhangs protect the earthen walls.

Costs of Rammed Earth Homes

The initial cost of rammed earth construction is comparable to conventional masonry construction, however the longevity of rammed earth homes far passes that of traditional homes. 

 

The average stick-frame home has a life span of 49 years, while a properly built rammed earth house can last 1000+ years. The primary factors affecting the cost are design and site characteristics.

Did You Know?

In modern rammed earth 5-10 % cement is added as specified by an engineer. Rigid insulation is oftentimes inside the rammed earth wall for thermal resistance as well as steel for seismic reinforcement.

image via Dwell

Green Roof Homes

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Images via Dwell

Green roofs, or 'living roofs', are rooftops covered with living vegetation planted in lightweight engineered soil.

Green roofs involve more than tossing plants on the roof and letting them grow. These roofs require drainage material and a waterproof membrane along with careful plant selection. Scroll to read about benefits and challenges of green roofs
 

Why Green Roofs? 

Green roofs serve several purposes:
 

Did You Know?

Newark, NJ was the next closest city with nearly 600,000 square feet of green roofs. The cities rounding out the top 10 are New York City; Seattle; Portland, OR; Toronto; Philadelphia; Chicago; Culpeper, VA; and Gaithersburg, MD.

Photo via Houzz

Challenges of Green Roofs

Photo via Houzz

Green roofs offer many benefits, but there are some added structural challenges that are important to consider:
 

Types of Green Roofs + Costs


The longevity of green roofs has the greatest effect on savings,
whereas installation and maintenance have the greatest effect on cost (maintenance costs are even greater than the installation premium).



Recover Green Roofs
has found that extensive roofs can cost about $10 to $50 per square foot, while intensive roofs can cost from $20 to $200+ per square foot.