I have an attached garage, but only the breezeway wall to the house is a common wall. I know the common wall should be insulated, but what about the other walls, and the ceiling? I want to drywall it, and the contractor suggested that insulating the whole garage will help with moisture, as well as keep it warmer. I don't use the garage as a workshop, so I don't think the marginal warmth in this unheated space would be worth the cost. But if insulating will help the drywall last longer, and cut down on moisture, I'd do it. Anyone have some advice?