
Insulation + drywall package
Batt insulation in walls and ceiling, 6 mil vapour barrier, half-inch drywall hung. R-12 in standard walls, upgradeable to higher R-values.
Insulation is the difference between a heater that cycles a few times an hour and one that runs all day. The vapour barrier keeps the moisture from a warm garage out of the wall cavity, where it would condense against cold sheathing.

