My attic r12 to level the bottom cord of rafters two layers r20. Walls 2X6 plus 1 1/2” ridged on exterior. Shop done same way. Don’t know if it was or is worth it but it’s there. My friend works for Manitoba Hydro as an energy consultant he tells me when heating with electricity you will never recoup the cost of a triple pane window over a double pane window. Followed his advice seems to be working
