Up to code natural building

I have lived in Spain most of my life. There is currently a growing movement to build with natural materials, which isn’t actually much of a novelty since that’s the way most houses were built less than 50 years ago. The problem is that now, tradiitional building isn’t contemplated in the building codes. I know many people in other countries have faced a similar situation and in some places have managed to have the codes changed or have figured out ways for their natural building methods to be up to code. I want to document the ways in which this has been done. If anyone would like to share their experience, I’m sure it would be helpful for us.
Thanks

I know in San Diego County, CA, USA we just recently added Straw Bale and Light Straw/Clay code guidelines to our building code, from the 2015 IRC.
It probably took a bunch of lobbying and fighting by dedicated organizations and individuals to get it to go through; Rammed Earth also makes a appearance here.

2016 CalGREEN Code Guidebook

most alternative building codes are covered by a catch-all phrase such as this:

Alternate Materials, Designs and Methods of
Construction
Consistent with the Health and Safety Code, and other parts of Title 24,
CALGreen also allows the use of any approved alternate material, appliance,
installation, device, arrangement, design or method of construction
not specifically addressed by the code. The alternates are required
to be evaluated on a case-by-case basis and shall be at least equivalent to
the prescriptive requirements of the code. See Health and Safety Code
Section 17923, and CALGreen Section 101.8 for further details and references.

and usually it means they want to violate your natural design with all sorts of plastic coverings, chemical binders, steel framework, and other terrible gick.

I'd like to see traditional structural cob make the same leap, but that will never happen (likely due to earthquake safety concerns, but more so just crotchety defiance by the Dept of Making You Sad.)

Thanks for your answer Dustin. It seems strange to have to fight so hard for something that has been done for such a long time. I’m also researching other parts of Europe. I recently spent time in Morocco, which is beautiful, in part because of all the building done with clay, fibers, lime and all the other natural materials used forever, and still.