COB & Building Codes

This is a VERY exciting moment in the history of Cob Building!!! The International Code Council approved and passed the proposed Cob Construction Appendix for inclusion into the 2021 International Residemtial Code!!!! NOW is the crucial moment in time for radical positive change in the Building Culture towards natural, healthy, durable, fire-proof, earthquake-friendly, sustainable and BEAUTIFUL building techniques, the most perfect one being COB of course!!!! Right now any jurisdiction can adopt it easily into their Building Code and anyone can ask their jurisdiction to do so.  It is adoptable and useable by anyone anywhere in the world so tell your local architects and engineers to visit where they can find the Appendix and all the supporting documents.  Let’s change the world one cob house at a time!

At this time the only countries with fully adopted Earthen Building appendices in their codes are New Zealand, Germany, the UK and France.  The International Residential Code has  Straw Bale and Light Straw Clay appendices thanks to the hard work of Martin Hammer and many progressive architects, engineers, builders and consultants in the Cob Research Institute.  They have prepared the path for Cob in the IRC.

If your building department requires an AMMR (Alternate Means & Methods Report), you will need to hire an engineer or architect to craft a design plan to have your cob building approved. Now they can use the approved Appendix. Alternatively, they can use a shortcut and design a post and beam roof support system with non-load-bearing cob walls. If you live in a county that uses Code K, you are fortunate.  It is the owner-builder code which allows you more freedom to get your non-code prescribed cob building approved.  Currently there are 12 counties in CA that accept Code K.  Please visit the Cob Research Institute’s website for the latest information on building a permitted cob building as well as references to building professionals that can help you.  As a cheaper way to go with your architect and engineer, have them use the proposed Cob Construction Appendix available to all on the CRI website.

In France there is a resurgence of earthen construction, called “pisé” , “torchis”  and “bauge” in certain regions which traditionally used their clay soils to build with.  They are renovating as well as building new walls with their traditional technique of ramming earth inside of wooden forms that move up the wall.  In England and Wales cob is well-accepted and there are regions, like Devon, where there is a higher presence of old cob houses with 2-foot wide foundations.  Germany is also active and has a section for Earthen Building in their Codes.  Biking through Europe there was not one country that did not have earthen buildings in their rural areas.  While I legalized the first load-bearing cob building in the coastal area of California (high earthquake risk), I do not recommend retrofitting an existing cob building, at least not if you have to do the unfortunate things I had to, to mine.  I sure learned alot!

John Fordice has spearheaded the beginning of a Cob Building Code with the Cob Research Institute based in Berkeley, California and is a central clearinghouse for the latest developments on legal cob building.

Bruce King is an engineer and architect who is known for his knowledge of straw bale and cob, as is Martin Hammer, a Berkeley-based architect who is the lead author of the Cob Construction Appendix to the IRC.  He was lead author in the Straw Bale and Light Straw Clay appendices.

Michael Smith is my go-to brilliant cob builder and all-around knowledgeable expert in conventional and ecologically-friendly construction methods.  Author of several books, he now lives quietly with his family in northern California on their goat and veggie farm, while continuing to teach workshops, consult and write.

Art Ludwig of Oasis Designs has just submitted a proposal for the first Low-Income Cob Village in the US in Santa Barbara, California. If you would like more information regarding this project please contact him.  Check out the video: