I built a 2200 sq. ft. ranch ans put 2" styrofoam on the outside of the block. Since I got 250 studs for free I decided to build the walls in the basement and cover them with 3/16" plywood I also got for free. After it was all done my basement went up 2 degrees. The joist box already had 3" closed cell foam anyway. I'm a bit disapointed it ony went up 2 degrees though. Just in case some want to do their basement walls this is what I got out of it in case anyone cares.