How to Build a Corner Shelf for a Desk

Place a measuring tape on the desk in the corner where you want to build the shelving unit. Lay the measuring tape along the longest side of the desk and determine how long you want the corner shelving unit to be. This likely depends on how long your desk is. Write the measurement down. Move the measuring tape 90 degrees to measure the width of the desk. Determine how wide you want the corner unit to be. Larger desks allow you to use the full width of the desk while smaller desks may only allow you to use about half the total depth. Write your desired measurement down.

Hold the measuring tape up against the wall vertically, starting from the desk’s surface. Determine how tall you want the shelving unit to be. Leave at least 10 inches per shelf, including 1 inch per shelf to account for the wood’s thickness and the end panels. For example, a corner shelving unit with three shelving compartments measures 34 inches in height -- 10 inches per compartment, 2 inches for end panels and 2 inches for shelving.

Lay a sheet of plywood down to draw the required shelving panels for the unit. Draw two rectangular figures that will serve as the two corner side panels for the shelving unit. One must measure the height by the length, determined in Step 1, while the other must measure the height by the width, also from Step 1, minus one full inch to account for the thickness of the wood.

Draw two panels that will serve as the bottom and top ends of the corner shelving unit. These pieces are identical and must be drawn as triangles. The two lines of the triangle that make up the 90-degree angle must be the length and width measurements collected in Step 1, except both must be 1 inch less than the measurement. For instance, if the desired length of the unit is 8 inches and the width is 5 inches, the end panel must measure 7 inches on one side of the triangle by 4 inches. The ends of these two lines must be connected by a straight pencil line to create a full triangle. Repeat this triangular design for any additional shelving you need. To continue with the example, draw two additional triangular designs with the same dimensions for a three-compartment shelving unit.

Cut the two corner side panels and the triangular shelving and end panels with a circular saw. Remove all splinters and cracks on the surfaces, edges and sides of the cut panels with medium-grit sandpaper.

Place the two side panels beside one another so they create the frame for the corner shelving unit. The two panels must stand on the 1-inch-thick side and stand as tall as the desired height. Ensure the adjusted-sized panel is being overlapped by the second panel in the 90-degree corner so you get your desired length and width dimensions. Place a level on top of the L-shaped structure and drill 1-1/2 inch long screws through the overlapping piece to connect the two panels in the corner. Use at least one screw every 2 inches for optimal support.

Lay the L-shaped unit down and insert one triangular piece into the 90-degree angle so the sides match up to the dimensions of the two side panels. Slide the piece to one end of the L-shape so it serves as a bottom piece. Attach it to the structure by drilling long screws through the side panels so the bottom panel is secure. Repeat this step with the top panel at the opposite end.

Insert your shelving pieces in between the bottom and top panel, spacing them evenly apart. To continue with the example, space the shelves 10 inches apart and attach them in the same manner as the top and bottom panels. When done, place the corner unit upright so it rests securely on the desk corner.

Apply a coat of paint or stain on the entire shelving unit if desired.