Rubble stone foundation Q

At what measurement is stone no longer considered "rubble". The reason I ask is because I live in earthquake zone D0, and rubble stone foundations aren't allowed per building codes. However in the future I want to build a cob home, with a stone foundation and I will need to get permits for the building of the structure. If I want a stone foundation, the stones will have to be of a size not considered "rubble". Or is it completely out of the question, given my location?

Hi Kris,

Welcome to Permies...

At what measurement is stone no longer considered "rubble"...

"Rubble" is a very generic and regional vernacular for ether "scrap masonry" and/or stone in the 100 to 200 mm range all the way down to 50 mm.

If I want a stone foundation, the stones will have to be of a size not considered "rubble". Or is it completely out of the question, given my location?

And...probably spec'd by a PE, a master stone mason, experienced stone artisan, and/or some other person with germane skill sets if in a municipal area. We don't need detail yet your generic building area will assist in what the rules "may be." No matter where it is built, a well laid out and considered blueprint is in order for such a build.

If is achievable in your area, yet may be a challenge and some compromises with "who does it," "how it is facilitated" and some other structural consideration may have to take place.

Regards,

j