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September 14-19 2021

The Art of Natural Plasters 

Instructors: Athena Steen of the Canelo Project, Michael G Smith 


Cost:  $750 includes camping and meals. $75 discount for full payment by August 1 and for families and friends registering together ($150 maximum discount per person). Half price for children aged 5-15. Some scholarships and work exchange opportunities for those in need.


Delve into the world of natural plasters with two master craftspeople and teachers. Learn to beautify and protect natural wall systems such as straw bale or cob and also to “naturalize” your conventional home with a fireproof and health-enhancing earthen finish. Clay plasters can be surprisingly durable, beautiful, economical, ecological, and are the easiest material for novice plasterers to develop their application skills. Some of the things you will learn include:



Straw-clay sculpting plaster - good for sculpting and for thick protective plasters over vulnerable wall systems such as straw bale

• Troweled clay/sand/straw plaster for exterior and interior finishes

• Fine clay plaster with no straw for smooth finishes and wall carvings

• Abstract sculpting and decorative carving designs

• How to find, test, and ecologically harvest clay soil

• How to select and use Japanese trowels and hawks

• Surface preparation for plaster application over natural walls including straw bale, straw-clay, and cob

• How to apply clay plasters over sheetrock, painted walls, wood and even concrete surfaces to “naturalize” a conventional home

• How to develop and test your own earthen plaster recipes

• Adding glue, lime and other hardeners for exterior surfaces or wet situations

• Mixing plasters by hand and by machine

• How to design your home and select finishes for maximum durability


Three meals a day will be prepared on site, largely from local organic ingredients. Camping is also available on site. Access to the land is somewhat challenging due to our steep unpaved road. Participants will park nearby and be shuttled to the site. Guided morning yoga asana practice will be offered 2-3 times a week, with space available for your own practice the remaining mornings.  

The building you see above is the building we will be working on. The timber frame was built from lumber harvested on site to stack functions with watershed regeneration and fire prevention. All of the dimensional wood was milled and pond-cured on site. Walls will be built during the workshop from straw bales, straw-clay, slip-and-chip, ricecrete, and other lightweight insulating systems, with a sculptural cob wall for the Water Altar, as well as arches and other decorative design elements.

Athena Steen was one of the pioneers of the straw bale revival, building her first straw bale home at the age of 19. In 1989, with husband Bill, she founded The Canelo Project, a center for natural building and cultural revival in southern Arizona. Together they have developed many innovations in straw and clay construction, ranging from simple straw bale pinning techniques to high-fiber “light adobes” to a revival of poured adobe floors. They emphasize everyone’s capacity to house themselves beautifully and inexpensively, using local natural materials and innate wisdom. They have worked extensively on low-income husing projects in Mexico and traveled and taught all over the world. Athena and Bill have also written half a dozen books, including “The Straw Bale House” (Chelsea Green, 1994). Well known for her artistry with natural finishes, Athena has collaborated on art museum installations at the Smithsonian’s National Museum of the American Indian in Washington D.C. and several other museums. Learn more here:


Michael G. Smith co-founded the Cob Cottage Company, along with Ianto Evans and Linda Smiley, in Oregon in 1993. He helped organize the first Natural Building Colloquium in 1994. He wrote “The Cobber’s Companion” in 1996 and co-authored “The Hand-Sculpted House” (Chelsea Green, 2002) and “The Art of Natural Building (2nd edition, New Society, 2015).” He has experience with a wide range of effective low-cost, low-tech building techniques including cob, straw bale, and many lightweight natural infill systems. He has taught hundreds of hands-on natural building workshops, ranging from one-day earthen oven builds for children to 12-week professional trainings. He enjoys consulting with owner builders to help them design and build successful energy-efficient natural homes. He is also on the Board of Directors of the nonprofit Cob Research Institute, which wrote the first building code for cob in the world and successfully advocated for its adoption into the 2021 International Residential Code. With his partner and children, he stewards a 20-acre organic farm in Yolo County. Learn more at

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