[Cob] Foundation for inside walls?

[Deborah Denmark]

I have read quite a lot so far on the building process for cob and have either overlooked this info or else it really is not talked about much.

I understand the foundation part for exterior walls but what is needed for interior walls that are thinner?

I am thinking that interior features like benches or massive trombe walls for heat collection need foundations just as substantial as the exterior walls.  But I have not found info to support that also.  Just using what common sense I have.  Am I correct on this?

Thoughts? Knowledge? Experience?

Thanks,
Deborah