Can you insulate an existing slab on grade floor?
...to dig gown a foot or so to lay the insulation and be able to cover it again with 6 to 8 inches of soil. So as for aesthetics, you can (and must) bury it.
The only other solution is to build up on the inside by adding a few inches of insulation, a subfloor, and new flooring. That isn’t always even feasible based on cei...