As the "Energy CHRISTsis" gained momentum in the early 70s .... a lot of new technology was applied to so called curbing unnecessary use of heating fuel. Some folks insulated below grade on the inside with a vengeance. Others began to experiment with "alternative" fuel
Years later -these same folks who insulated unwisely found them selves with a house settling into a crumbling foundation or a toxic waste field of mold to live in.
because the heat escaping into the foundation was protecting it from the freeze -thaw cycle and keeping it dry
- once the heat of the house was isolated -- the walls and footings were set on the front line -in harms way - Then, it was only a matter of time down the path of doom.
UNLESS the structure is built to modern standards of construction -- you know that ugly line -- "To Code" ---well you would be far better served to excavate and insulate on the OUTSIDE --from freeze board and down well below frost line
I know the next line will be 'But I cannot afford that" - reminiscent of a septic thread recently????
well then --plan on moving soon because you will not pay for a new basement either