My single story home was built in the 60s so I am lucky to have insulation at all. The exterior siding is thick lap siding (probably cedar), then tar paper, then tongue and groove solid plank sheeting, and then 2x4 stud walls "filled" with 1.5" foil faced fiberglass bats, then sheetrock and 40 years of paint. The flooring is 2x6 tongue and groove over beams with zero insulation above a crawlspace, and the ceiling is about 5" fiberglass batts that have been compressed over time to 3" in some places. So ceiling is R-11, walls R-5, and floor is R-0. The windows are single pane with aluminum frames. My big old Lopi can heat the house up but the home cools quickly when the fire dies or when the bedroom doors are shut. Individual electric wall heaters provide heat when the fire is out. I have concluded the best way to spend my next money for reduced energy consumption is insulation. I am finishing up some wiring work and then the attic will be sealed from the living space below, have soffit insulation deflectors stapled at the edges, and blown in fiberglass to the R-38 level at least. Ceiling is easy and I think will give a good benefit. The windows are set to be swapped out for double pane vinyl windows in the summer. This will give major sound reduction and eliminate the drafty old single paners. The floor will be at least R-7 from below, but I am not quite sure how to do it just yet since the beam spacing is 5 feet and I have a small crawlspace entrance. The walls are my question though. Without ripping down the sheetrock, is there a way to improve the wall insulation value? Standard R-13 batts would be a huge improvement but how to get them in there? How would you suggest improving the walls or would you just leave the R-5 be? Our climate is pretty moderate with winter lows in the teens but usually 30s through the winter nights. Thanks is advance.