Large, double-paned glass windows, winding staircases, two stories and an open concept design may not be what comes to mind when you think about dirt homes. However, earth-friendly homes made from natural resources, such as dirt, are not limited to small, single room cottages. This type of sustainable home is the ideal way to embrace eco building. There are two main types of earth buildings. Cob and rammed earth structures are made from local supplies using a method that has been around for thousands of years.


Cob homes are constructed with ingredients like straw, clay, sand and water to make a type of plaster that is most associated with traditional British structures. Rammed earth homes are made from dirt, chalk, lime, gravel and water and are most associated with the Adobe houses in Mexico. There isn’t just one way to make these types of houses. The formula is flexible so if one ingredient is in short supply, you can amend the clay using other ingredients.


The idea of working with natural materials doesn’t always sound appealing when you first hear about it. The houses may seem flimsy, flammable or intolerant to extreme temperature fluctuations. However, the opposite is true. Some of the oldest structures that are still in existence are made from cob and are thousands of years old. Earth homes are found in hot, dry, cold and wet climates including Canada, Britain, Mexico and Africa. This means that they can be created to fit into any of Australia’s climates.


Many amendments can be made to make the home suited to a specific climate. Earth homes that are built in cooler climates are easily insulated using straw bales. The bales are stacked to create the walls and the earth plaster is spread over them. The walls end up being incredibly insulating and they work as a sound barrier. In hot climates, a thatched roof with a lot of overhang or a covered porch keeps the sun off the earth walls. This keeps the house cool even in the hottest climates. For wet areas, extra lime is added to the earth and the house is built on a higher foundation so the clay isn’t constantly sitting in water. Local builders that are experienced working with natural homes can help determine the right formula and structure for the climate.


The insides of an earth-home do not need to be simple or barren. You can design the home to include imbedded personal touches, such as coloured glass, in the walls or put a carving in the clay before dries. Add a wood stove to the center of the main room for heat and install hardwood floor. Build a bench with the clay so it is part of the wall and you’ll have permanent seating in the house. You can finish the home in many ways, like using thatch, rubber tires or metal roofs for long-lasting secure protection. Add solar panels to your roof for sustainable electricity. Whatever you choose, your home will have all the personal touches and amenities that any other home does. The only difference is, you’ll know exactly what went into making it and that your choices were as natural, healthy and earth-friendly as possible.


Earth building can be quite time consuming or it can be accomplished in a matter of weeks. If you are building a small structure and have a group of friends to help, you can erect an outdoor cob oven during a weekend. However, a single person or couple that is building a large two-story home may take several years to complete the project. The same goes for the costs. A small project made mostly from free supplies maybe cost almost nothing, but an elaborate home can cost over $300,000. Blogger Brian Liloia, built a small cob house for under $3000, which he uses as his permanent residence in Dancing Rabbit Ecovillage in Missouri, U.S.A. Liloia’s project took about nine months.


This idea may seem overwhelming but you don’t have to start out with a large, two-story home. Instead, you can try building a cob wall, outdoor oven, hut, cottage or storage shed to try your hand at working with the earth. Once you are more practiced you can move onto bigger projects.


Learn more about earth building by joining an organization. Earth building associations will have literature, workshops and projects that you can participate in. This is a good way to get experience and knowledge. You’ll also make friends who can come help you when it’s your turn to build.


References:

small-scale.net/yearofmud/about/

vivahomes.com.au/Building-Cob-Walls-Sustainable-Homes.aspx

greenhomebuilding.com/QandA/cob/where.htm

enviro.org.au/cob_building.asp

cobworks.com/articles-videos/

cobhouse.net/faq.html

housealive.org/faq#1a

ebaa.asn.au/