I own a 1957 Cape. The previous owners converted the attached 1 1/2 car garage into a spacious sunken living room. The attic in the livingroom i know needs to be reinsulated(only 3" insulation).The question i have is under the floor. On the outside there are 2 (4"x8") airvents. When i opened them up there is no insultion under there.Do i need to have insulation under there? If so how am i going to do that.There is no access to get under there and if there was one i would not be able to fit under there. Any ideas or suggestions would be great!