My door is aluminum. It has a core of Styrofoam, and one needs a strong, lengthy jigsaw to be able to cut into the aluminum after drilling the 3/8" holes which will cut the inside area of the template. It was not easy, and the aluminum vibrates/shakes as it's being cut and easy (as in my case) to go off the penciled mark - then the cut being ragged. A wooden door, I surmise would be much easier with no vibration of the piece being cut. One gets only one chance at the cut of the aluminum door or a screwup occurs and hence, a new door would be needed in addition.