Earthen Plasters and Floors

September 12-16, 2022

Hello friends-
I greatly enjoyed last year’s workshop series at Abuela Gardens in Willits CA. In case you missed them, we will be offering two more Natural Building workshops there in 2022. There are other great workshops on offer including a Permaculture Design Course and an Herbal Medicine Apprenticeship. See more details here:

I hope to see you at one of these excellent events!


Michael G. Smith, Sasha Rabin

A great opportunity to develop your skills and understanding of earthen finishes, including:

• straw-clay base coat plasters for sculpting and protection

• endless variations of clay finish plasters for durability and beauty

• durable, water-resistant earthen floors

These techniques are suitable for natural buildings including straw bale and cob, as well for “eco-renovation” of conventional homes, where they can add natural beauty, thermal mass for increased energy efficiency, and health-enhancing moisture modulation. Plus, they are fun, artistic, and inexpensive!

Each day includes many hours of hands-on skill building, with an emphasis on proper tool use, recipe development and testing, and site organization for efficiency and flow. Learn to find, test, and ecologically harvest your own clay; how to choose the most appropriate finish option for your building project; how to prepare various wall surfaces to improve adhesion; and how to design your home to make the plasters last.

Rocket Mass Heaters and Natural Building

July 9-13, 2022

Hello friends-
I greatly enjoyed last year’s workshop series at Abuela Gardens in Willits CA. In case you missed them, we will be offering two more Natural Building workshops there in 2022. There are other great workshops on offer including a Permaculture Design Course and an Herbal Medicine Apprenticeship. See more details here:

I hope to see you at one of these excellent events!


Sasha Rabin, Michael G. Smith, Colin Gillespie

Like two jam-packed workshops in one! Come build a rocket mass heater, a super-efficient wood-burning stove that stores heat in the thermal mass of an earthen bench. Learn about the many exciting RMH variations and possibilities: batch vs. downfeed! cooking! water heating! hypocaust floors! 

At the same time, we will be exploring a range of high-insulation and thermal mass natural building systems including cob, straw bale, light straw-clay, and slipsquatch (redwood bark and clay.) We will also install the drainage layer and the first pour of an earthen floor.

Students will rotate daily between several hands-on projects so that they get to know each of these techniques. Daily lectures cover the theoretical knowledge you will need to design your own project: how a RMH works; dangers, do’s, and don’ts; thermal properties of natural building systems; and how to combine them all into an energy-efficient passive solar home.

Straw Bale, Cob, Light Straw-Clay, Slip-and-Chip, Clay Plasters

Natural Building with Michael G. Smith

Tonasket, Washington

July 24-30, 2022

Learn the techniques you need to build a low-carbon, energy-efficient home in any climate. This workshop teaches the hands-on skills needed to construct both high-insulation (straw bale, light straw-clay, slip-and-chip) and thermal mass walls (cob), using low-cost, locally available materials including clay soil, straw, and wood. These wall systems are easy to learn, inexpensive, beautiful, durable, and fire-resistant. Which one you choose depends on your climate, design, and local resources – or build a hybrid home utilizing multiple wall systems to maximize efficiency and design flexibility!

Most of each day will be spent constructing an actual hybrid home. Hands-on building will be supplemented with daily lectures and slide shows that provide the theoretical understanding you will need to design your home: finding and testing clay soils and other local resources; foundations, drainage and moisture protection; passive solar design; structural and thermal properties of different natural wall systems; how to develop your own successful recipes for cob and natural plasters, and more!

Camp under the trees on this remote and peaceful community property in the Okanagan Valley. Three delicious meals per day will be prepared on site, emphasizing organic and local ingredients. Meet new friends who want to help build a healthier future. Register soon, as space is limited.


Michael G. Smith has nearly three decades experience with natural building; he has taught over 120 hands-on workshops for everyone from school children to professional builders and designers. In 1993, he helped found The Cob Cottage Company in Oregon; the next year, he organized the first Natural Building Colloquium. He is a founding director of The Cob Research Institute, which developed the first building code for cob. He is co-author of The Hand-Sculpted House and The Art of Natural Building. He now lives and farms with his family in Northern California.


The base fee is $840 per person. Our aim is to provide the most enriching learning experience possible that is accessible to everyone.  We have many discounts available in addition to work-trade opportunities.  If you want to join us, we want you to be here so let’s make it happen!  Don’t hesitate to reach out with any questions. Natural building sites are family friendly and we welcome all ages (inquire about rates & special circumstances for minors).

  • Family and Friends discount 10% off: Register together and each person gets a discount.
  • EARLY BIRD Discount 10% off: Pay in full by June 10th to receive discount.
  • BIPOC price 20% off:  We acknowledge that many techniques of earthen building have been learned and adapted from cultures around the world that have been marginalized and even destroyed. May this be a way to include people who have been systemically isolated from ancestral knowledge and hereditary wealth.
  • Discounts are cumulative up to a maximum of 25% off.
  • 1 Economic Hardship/Full Work trade available – includes arriving before the workshop to set up and staying after to clean up.
  • Partial work trade for partial enrollment discount is available (please inquire).


Enrollment is limited so please register early. 50% deposit required to reserve your spot. The remaining balance is due upon arrival. Please register here:

Natural Building Intensive

July 10-24, 2021

Abuela Gardens, Willits, CA

  • Cob Straw Bale
  • Light Straw Clay
  • Slip and Chip
  • Ricecrete
  • Mushroom blocks
  • and more!

Instructors: Michael G. Smith, Colin Gillespie, Blair Phillips

Cost: $1750 includes camping and meals. $100 discount for full payment by June 1 and for families and friends registering together ($200 maximum discount per person). Half price for children aged 5-15. Some scholarships and work exchange opportunities for those in need.

Learn skills, techniques, and design theory to create your own beautiful, durable, energy-efficient home from local and site-harvested materials. Most of each day will be spent practicing a wide range of hands-on natural building systems, some ancient and time-tested, others experimental. This workshop teaches a wide variety of techniques that you can choose depending on your climate and local material availability. We will also give you the theoretical knowledge to design a regionally appropriate passive solar home. Lectures, slide shows, demonstrations and tours will cover many topics including: sustainable forest management; ecological harvesting of timber and clay; overview of round pole timber framing; practical tests for soils and earthen mixes, manual and mechanical mixing techniques for earthen building; passive solar design; thermal and structural properties of natural building systems; hybrid natural building design; design for weather and durability; working with codes and permits; integrating art and sculpture; and natural plasters and finishes.

Located 20 minutes from Willits in the heart of Mendocino County, Abuela Gardens is a working demonstration site dedicated to helping the growth and healing of all beings through a continued dialogue with nature, water, food, and medicine. This approach is accomplished by incorporating community, music, healing arts, and silence within a multidimensional design strategy. Our action plan is to communally care for the Earth by growing as much of our own food and medicine as possible, regenerating the forest and aquifer we depend on, building with earth and regeneratively harvested materials as well as developing habitat for a diverse interface of wild and domestic creatures including bees and hummingbirds. This workshop will enhance the infrastructure of the center by constructing a focal point for meeting and eating as well as cold storage for seeds, fermentations, roots and other food.

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. At the end of the first week, we will take a field trip to the coast where we will visit other local natural buildings and receive a final gift of wood from the mama ocean. 
Register at https://www.abuelagardens.comQuestions? Call Blair at (707) 272-2929 or email i[email protected]

Instructors: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” (published by 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 cob for code 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

Colin Gillespie has worked in the construction trades for over 20 years, with previous experience in integrative landscaping and sociology. He has dedicated himself to the study, mindful practice, and teaching of Natural Building, Permaculture Design, and Regenerative Forestry through numerous trainings and homestead development projects. Son of an architect and a physicist, his attention to detail coupled with a passion for creating beautiful and wholistic infrastructure and landscapes has inspired him to produce exemplary structures combining ancient and modern building techniques. Many of his projects feature elegant round pole timber frames coupled with thermally efficient straw bale, coated with robust contoured cob and plasters. Familiar with many systems of construction from stud frame, wood joinery, masonry, and several clay based mediums, Colin thrives on utilizing local natural resources, often straight from the building site. He champions keen observation, considerate visioning, thorough planning, all tempered with good humor and adaptability to allow long term efficiency, functionality and beauty to emerge naturally.

Blair Phillips, founder of Abuela Gardens, has a BA in Environmental Studies with an emphasis in Agroecology and education. He is a certified permaculture designer and teacher who has studied with the best teachers including Dr. Elaine InghamGeoff Lawton,Darren DohertyPenny Livingston, Brock Dolman, Ian Davidson, Steve Gliesman, Michael G. Smith, and Michael Flynn. Blair is also the founder of Common Vision, ( a nonprofit organization responsible for planting thousands of fruit trees in California, many of which were planted on school campuses by a waste vegetable oil powered caravan of earth educators. Blair has worked internationally to propagate an additional 7000 trees in Guinea, West Africa, and to build a superadobe dome structure for a school in Dogon country, Mali. Settling into the hills of Willits in 2012 inspired Blair to develop an intimate relationship with the watershed, designing his farm and homestead based on a regenerative relationship with the surrounding environment. 

The building you see here 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.

Four-Part Natural Building Series, May 2020

Hello Friends-
I’m going to be part of the teaching team for a very exciting workshop series coming up in Willits, Northern California. Over four 3-day weekends, you can learn about round pole timber framing, cob, straw bale, wattle and daub, adobe, passive solar and ecological design. For more details about curriculum, schedule, pricing and registration, click here:
Happy Spring!


Dear Friends-

I’m excited to announce an upcoming workshop series that combines nearly all of my primary interests: natural building, farming, education and intentional community. In collaboration with the amazing folks at the School of Adaptive Agriculture, located at the Ridgewood Ranch community near Willits, California, we’ll be building an efficient low-tech walk-in produce cooler for the farm, using straw bales, clay and lime plasters. The workshop will cover all the essentials of how to construct any simple straw bale building. I’ll be co-teaching with my friend Ananth Nagarajan, a skilled and passionate builder who keeps up on all the latest developments in natural building. For details of schedules, cost and registration, please go to

Hope to see you there!

Straw Bale and Clay Plaster Natural building course

New Workshops for Spring 2017

Hi friends-

We’ve been busy at Spreadwing Farm, with a bunch of new building projects. One of them is a new workshop and packing shed complete with straw bale walk-in coolers. I’d like to show you what we’ve been doing and invite you back into the mud and straw. Please join us for one or all 3 of these upcoming workshops!

Let me know if you have any questions. Here’s mud in your eye!


2017 Natural Building Flyer

Wall to Wall workshop series


Hi, friends-

I’m excited to announce a series of 5 4-day hands-on Natural Building workshop that I’ll be teaching with my colleague Amanda Fischer in May and June of 2016 in Willits, CA. This is a rare opportunity to get a highly in-depth natural building training. By attending all 5 workshops you will learn 10 building techniques plus a great deal of building science, design methodology, and other theory. Or you can pick and choose which workshops to attend based on your interest in specific techniques. For more details or to register, go to

Hope to see you there!


Building with Earth and Straw

Natural Building Workshop with Michael G. Smith

Join me for a 6-day hands-on workshop June 14-19.

This hands-on workshop focuses on easy-to-learn, low-cost, environmentally-friendly building strategies especially appropriate for our climate. Beginning with an earth-sheltered steel shipping container, we will be attaching a straw bale wall on the south side for insulation, with windows for passive solar heating. We will also begin construction of a cob (sculptural load-bearing earth walls) studio, recessed into the ground with a low-impact earthbag foundation. Clay soil from the site will be used for cob and for plastering the straw bales and earthbags. About 6 hours each day will be spent building together, with an additional 2-4 hours of lectures, presentations, and a tour of local alternative buildings. Presentations include: evaluating and harvesting clay soils for building; effective use of natural materials for energy-efficient passive solar designs; household water reuse and composting toilets; and a visual tour of natural buildings around the world.
Instructor: Michael G. Smith helped found The Cob Cottage Company in Oregon in 1993. Since then he has taught over 100 hands-on natural building workshops and designed and/or helped build over 50 natural structures. He consults with owner-builders on using on-site and locally available materials to build efficient, low-cost, comfortable and beautiful homes. He is the author or co-author of 3 books on natural building, including The Hand-Sculpted House and The Art of Natural Building.
Cost: $550 if paid in full by May 12; $650 thereafter. Includes instruction, on-site camping, and 3 delicious vegetarian meals per day. $50 discount (each person) for families and friends registering together. Youth 10 – 18 half price. Children 9 and under free. Some work trade positions available. The total size of the class is limited to 16, so register early.
For more information or to register: [email protected]