The workbench, originally built from pieces of the old garage shelving, had been attached to the wall studs. I detached the bench frame, added some back legs and extra bracing, and put a couple dozen more screws in it for good measure. The shelving is attached to the bench and is built from 2x4's and some ShelfLinks from "2x4 Basics", which just screw into the lumber and form a rigid structure.