30 inch bathroom vanity used in many shapes and sizes. It was have sinks in them. Mostly bathroom vanity is 30 inches tall including the sink top. Moreover, their common depth 22 inches, including the top. To change the height or the depth of your 30 inch bathroom vanity, extend the height of the end panels and the width of the shelf.
Place two pieces of wood measuring 29¼ inches tall (vanity ends) on a worktable. Place the framing on the mark and draw a line of 20-inch width of the plywood. Measure in from one of the long sides of the plywood and make a mark on the line drawn in step 1 to 5 inches. Place the framing on the mark and draw a line to the bottom of end panel.
Applying glue on the upper edge of the studs and placing the plywood is 28½ inches long on top of the studs. This is the bottom shelf. Glue the panels on the top of the 30 inch bathroom vanity. This is called a spike strip. Turn the cabinet over as spike strip is facing up. Apply glue to the edges of the two end panels, the bottom shelf and the spike strip. Turn over the bathroom vanity as it is on the back. This is the toe board vanity.