Natural Building Holds Huge Promise for the Future
This summer’s adventure was a two-week hands-on natural building intensive workshop at Wanosh Forest Gardens in Willits, California. The main instructor was Michael G. Smith of Straw Clay Wood and Spreadwing Farm in Rumsey in the Capay Valley; with Avani Leitz and Viva Hansen also teaching and overseeing much of the work.
I’ve been wanting to learn more about natural building since I first moved to Davis in 2012 and became aware of Michael. It took me 11 years to finally make room for this experience in my I life and I was worried my body wouldn’t hold up to the intensive daily labor. But hold up, she did!
The highlights of the workshop for me were organic, mostly vegan meals prepared with love and intention; learning a plethora of different techniques from the Larsen Truss to earthbags, concepts like passive solar, thermal mass, and insulative versus conductive materials; and, finally, the gatherings, field trip to the beach, closing celebrations and ceremonies, jam sessions, and dance parties. Capturing the full feeling for you would be a challenge.
Luckily, my main intent is to convey the most important lesson learned: currently a rarely used set of methods and materials, natural building holds great promise for constructing low cost, ecologically sound, extremely low operational cost shelters.
What is natural building?
According to Wikipedia: “The basis of natural building is the need to lessen the environmental impact of buildings and other supporting systems, without sacrificing comfort or health. … A natural building … focus[es] on durability and the use of minimally processed, plentiful or renewable resources, as well as those that, while recycled or salvaged, produce healthy living environments and maintain indoor air quality. Natural building tends to rely on human labor, more than technology.”
The Wikipedia entry quotes Michael right up front: “As Michael G. Smith observes, it depends on “local ecology, geology and climate; on the character of the particular building site, and on the needs and personalities of the builders and users.” To quote Michael from his 2002 book, “The Hand Sculpted House,” “natural building implies profoundly different attitudes to places, building sites, ecology, work, and how we live in buildings. Natural building means paying more attention to all the details of how the world really works.”
Primary materials include cob (a mixture of straw and clay and often sand), straw bales, adobe bricks, quarried or field-gathered stone, gravel, bark, willow reeds, unmilled timbers, milled lumber, bamboo, plasters of various sorts, and used bottles. Concrete and plastic can have their place, but definitely do not dominate. Tools are primarily hands, feet, shovels, a “cobbers thumb” and various plastering trowels, but equipment as carbon intensive as backhoes can be very useful on a selective basis as well.
Despite the reality that many natural buildings are often quite small and single rooms, they can also be large and can always include conventional plumbing and electrical utilities, and all sorts of roofing systems and code-compliant foundations — all essential elements for the kind of home we’ve all come to expect. Full Belly Farm in the Capay Valley is home to a two story straw bale beauty with all the bells and whistles!
Low impacts and learning opportunities
Natural building is labor intensive, which is the main reason it might cost more during construction than conventional methods. On the flip side, according to Michael, conventional construction generally backloads its costs, with 25% up front for construction and 75% over the lifetime of the structure for “operations” (mostly heating and cooling). Natural building projects also produce far less emissions than conventional ones due to an emphasis on site available materials, natural materials, and thermal mass, insulating, and passive solar techniques.
Michael is the author and co-author of several books on natural building techniques. His most recent work, “Essential Cob Construction,” available January 2024, focuses on giving engineers, architects, designers, contractors, and owner-builders what they need to construct code-compliant, low-embodied carbon, and fire- and earthquake-resistant buildings from cob – a mix of clay, sand, and straw.
Yes, that’s right, there is code for cob! To date, California has adopted code for straw bale and light straw clay construction but not cob, despite the International Code Council adopting a model into the International Residential Code in 2021.
Michael will be teaching another workshop this summer at Wanosh, “The Arts of Natural Plaster,” with legend Athena Steen, from Monday September 18 to Friday September 23. Topics include wall preparation, straw-clay base plaster, clay and lime finish plasters, and more. Week two from September 24 to 29 will be taught by Viva Hansen and Blair Phillips.
Get more details here: https://wanosh.org/arts-of-natural-plasters
Since 1993, Michael has taught well over 100 hands-on natural building workshops, ranging in length from day-long oven building workshops for kids to twelve-week professional trainings. Many of the workshops are about a week long. Workshops are a great way to kick-start a natural building project with an expert leader and a group of enthusiastic helpers. They are also a lot of fun and often lead to lasting friendships.
- Pre-order Michael’s new book for professional construction “Essential Cob Construction: A guide to design, engineering, and building,” available January 2024
- Michael’s Straw Clay Wood web site
- “The Hand-Sculpted House” (Chelsea Green, 2002)
- An interview about Michael’s work with the Cob Cottage Company in Oregon
Yolo County is home to more than one natural building pioneer
As part of my follow through on this thread, I checked in with Jon Hammond of Indigo Architects and discovered that Jon, principal with Indigo Architects on 5th Street in Davis, has had a lifetime relationship with natural building. Davisites know the Dairy Queen wavy-roofline-conversion that is now offices for Indigo Architects and RepowerYolo, but other projects include Jon and Sayako’s home west of Winters, benches at the Davis Amtrak station, the Riverbank Teen Center in Stockton, and two police stations in Visalia and Dublin, all projects that make use of natural building techniques and materials—in particular, straw bale.
Steel, bricks, and concrete are carbon intensive building materials. Straw bale, on the other hand, is a great insulator, and when plastered is very fire resistant. One of Jon’s ADU straw bale projects survived a wildfire! Jon thinks of natural building techniques as “super beautiful” and definitely carbon sequestering. He noted that natural building is cost effective for owner-builders using the “friends and family” model, but that individual residential designs intended for general contractor-led projects have been less commonly pursued by his clients. What folks may not appreciate up front as part of a natural building construction project costs is the low operational costs later.
Jon related that the Visalia police station project used rice straw bales which appealed to that community of farmers who especially liked the idea of using an agricultural waste product. He said rice straw gives them grief because either it has to be burned or turned into the soil with external treatments because the decomposition process uses a lot of nitrogen. So rice straw bale-based structures are a win-win for sure.
The potential for natural building
While much work remains to expand the reach and viability of natural building on a larger scale, and in urban/suburban settings, the techniques hold great promise for addressing our housing crisis in a manner that respects the earth and those of us who live upon it. Natural building can deliver on the promise of a safe and secure future. I’m excited to see where it leads for you!
Michael and Wanosh’s workshops and his upcoming new book are great ways to find out more. With so many books and resources out there on natural building, it can be intimidating. Focus on the resources in this article to get started.
Indigo Architects web site: www.indigoarch.com
Sustainable Building Essentials book series
- “Essential Light Straw Clay Construction” (has copy of ICC code for free in the back)
- “Essential Prefab Straw Bale Building”
- “Essential Natural Plasters”
- “Essential Building Science”
- “Straw Bale Building Details” (straw bale code with commentary included)
- “The Art of Natural Building”
- “Using Natural Finishes”
Other cool stuff to check out
- The Natural Building Network https://www.facebook.com/groups/113862001535/
- The Cob Research Institute
- California Straw Building Association
- Emerald Earth Sanctuary: “After 35 amazing years of doing great things as a predominantly white community, we are entering into a long-term collaboration with two amazing Black-led organizations.”
- “Natural Solar Architecture: A passive primer” by David Wright
- “This Building Material May Hold the Key to Surviving Environmental Disasters Gaining popularity in parts of California, straw-bale construction has proven to withstand wildfires, tornadoes, and earthquakes” Architectural Digest by Dakota Kim 2018 https://www.architecturaldigest.com/story/strawbale-construction