The door was unavilable in a high R, which is why we got the job to build it in an R20. Built as stain grade finish by others. The garage was heated which was one reason they wanted to have a high R value. Higher insulation in a door can equate to hundreds of dollars worth of savings on heating costs, annually. Our doors are both nice to look at and very functional, ss seen in the photo above. This curved topped window door is an R 20 and runs almost silently.