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
