Not only can you build sustainably, now you can build to store carbon.

Rammed earth. Earthship. Light clay straw. These terms may sound new age and unfamiliar, but they are par for the course at the Ontario Natural Building Coalition’s annual Natural Buildings Tour. The tour is a key part of the ONBC’s mandate to provide information, support and community for those who wish to pursue natural building, either as homeowners or as building professionals.

The need to elevate awareness of natural buildings continues to grow. Many mainstream builders adhere to the building code, which is adequate for safety and comfort, but certainly does not represent best practices. According to the US Green Building Council, buildings are responsible for 39 percent of the nation’s carbon dioxide emissions.

With natural building, we can achieve much higher occupant comfort and satisfaction, while increasing measures such as energy efficiency and waste reduction. With the effects of global climate change on everyone’s mind, natural building also has the potential to act as a form of carbon sequestration. Many Ontario natural builders are beginning to talk about net zero carbon buildings, where less carbon is released than is sequestered in a finished building. With natural, carbon-containing-materials such as straw, cellulose and wood, these goals can become a reality.

2017’s Natural Building Tour boasted 34 homes and other natural buildings, with upwards of 500 people attending. Building techniques on display included straw bale, light clay straw, rammed earth and even an earth ship under construction.

New to this year’s tour was a facility composed of prefabricated light clay straw panels. These panels are created by ramming clay-coated straw into wooden forms, which are then plastered, shipped and assembled on site with the use of a crane. Such prefab methods can greatly reduce the time, labour and cost of a sustainable building project, and represent a promising new direction in the industry.

In the interest of including a diverse range of building options, the ONBC has decided to keep our definition of “natural” fairly broad. This means we are able to include some very interesting buildings in our tour, which may not be entirely natural, but we feel are ecologically sound, or at least allow us to think outside the box of conventional building. In recent years, we have seen some very impressive rammed earth structures being built. Although such buildings do utilize some cement in their construction, they incorporate thermally massive walls. These walls, especially when dark in colour, absorb large amounts of solar energy and re-radiate it into the home over time. This results in very stable temperatures, increased occupant comfort and lower heating bills.

It is our hope that our annual tour creates a positive buzz around sustainable, natural buildings and encourages folks to get engaged and excited about creating more of them. We encourage all interested parties to visit our website and keep their eyes open for our annual Conference and AGM in April 2018, as well as next year’s Natural Building Tour in September 2018:

If you are interested in learning more about natural building in the meantime, you can become a member and join our mailing list, by emailing And for more information on ongoing natural building workshops, please visit



Kristi Mahy is a former straw baler and natural plasterer, and now sits on the Board of Directors for the Ontario Natural Building Coalition. Her passions include vegetable gardening, good food, canoe tripping, jogging in the woods and learning new things with her little boy. She is also involved in local environmental campaigns and currently works from home as a carpenter, landscaper and gardener.

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