It is very important to apply the reasonable insulation method to refrigerated warehouse since temperature difference between storage and outside is so great. However, insulation method for refrigerated warehouse is not expressly provided in the Korean building code and there are few examinations for evaluation of each insulation method. Thus, this study aims to evaluate the economical efficiency of the refrigerated warehouse envelope with different insulation method(inside and outside insulation), temperature condition(0℃, -6℃ and -15℃) and insulation thickness(100mm, 150mm and 200mm / 50mm or 250mm). As results, it is proved to have the best economical efficiency when outside insulation method with thickness of 100mm(0℃ and -6℃) and 150mm urethane(-15℃) is applied.