• If a slab-on-grade is not supported by foundation walls, then insulation must not block heat from entering the ground under the perimeter.

• Insulation that may be subject to mechanical damages needs to be protected.
  This applies to insulation in many areas, such as:
  • Low overhanging floors that can be reached from the ground
  • Insulation in walls between the house and the garage

9.25.2.3.5) Insulation around concrete slabs-on-ground shall be located so that heat from the building is not restricted from reaching the ground beneath the perimeter, where exterior walls are not supported by footings extending below frost level.