Good question. The insulation value of our dual layer insulated door is R-14. Insulation will only slightly help your garage stay cool in the summer and warm in the winter. But insulation does make the door look nicer on the inside. Also, it tends to quiet the door down in its operation and decrease road noise. If these issues are not important to you, don’t get an insulated door. Please note, in spite of what some salespeople may say, insulation does not make a steel door more dent resistant. Dent resistance comes from thicker, heavier steel with high tensile strength.