We own a 45 year old ranch with a crawlspace in Southern MA. Our bedroom is part of an addition built within the last 10 years or so, but it's pretty cold in the winter. We have 4" thick styrofoam panels(?) and R-19 batts in the attic, but only a carpeted subfloor between the bedroom and the crawlspace. The crawlspace isn't insulated, but I've closed the vents so the pipes won't freeze, and there is 6 mil plastic on the dirt floor.
We have a lot of R-19 left, so my questions are : 1) Do I lay it over the existing batts in the attic, or should I use it on the joists in the crawlspace? 2) Could my problem possibly be a lack of insulation in the two bedroom walls that face the outside? (What's the best way to see if there is insulation in the wall?)