A frame extender for attachment to a stud is formed as an L-shaped body having two orthogonal legs, a short leg and a long leg. The short leg serves as a mounting surface to which a wall surfacing material can be attached, while the long leg is fastened to the stud. The long leg terminates in an outer edge which preferably has a toothed profile. An indexing mark is provided on the long leg, extending parallel to the short leg and spaced apart therefrom, and substantially traversing the long leg. The indexing mark is preferably provided by a discontinuity in the surface of the long leg that is placed against the stud. A preferred method for fabricating the frame extenders uses stock that can be pressed or extruded, and which is cut along a serpentine path to form a pair of frame extenders.