How to Build a Side Desk

Place the measuring tape on the existing desk and measure the width of it. Write it down. Determine how long you want the new side desk to be, taking into account that the new piece must overlap the entire width of the existing desk and then extend another three feet or more out from the front. Measure the width of the new side desk, if you want it to be different than the existing desk. In addition, measure the height of the existing desk and write it down.

Lay a sheet of 1-inch plywood on a flat surface, such as the floor. Draw a rectangle measuring the desired width by the desired length of the side desk. Cut the rectangle using a table saw. Sand the edges with medium-grit sandpaper. Apply the height measurement plus 1 inch to the two wooden pieces, which will become the legs, and cut them.

Apply the width measurement to the length side of the new desk piece and draw a line across the width of the desk on what will be the underside, using a ruler and pencil. This indicates the area that will overlap the existing desk. Draw four marks along the length side within the rectangle on both sides, a total of eight marks. These marks must be at least an inch apart and at least half an inch from the edges.

Drill eight holes at the spots where you made the marks. Use the 1/2-inch drill bit and do not drill all the way through the desk surface. Each hole should only be 1/2 inch deep. Insert wood glue into each of the holes and insert a 1-inch wood dowel into each. Let them dry.

Locate the center of the ends of each of the table legs by drawing lines from opposite corners on the 2-inch ends to form an X. Drill a 1/2-inch-deep hole in each of the legs at the point where the X-lines meet. Add some wood glue to the holes and insert a wooden dowel into each.

Flip the desk upside down, so the wooden dowels are sticking up. At the opposite end, position one desk leg where you wish to attach it. Ensure the wooden dowel in the leg is facing downward and make a pencil mark on the desk, where a hole must be drilled for leg installation. Repeat this procedure with the second desk leg. Drill the two holes to a depth of 1/2 inch. Add wood glue to the holes and push the wooden dowels on the legs into each hole. Let the glue dry.

Turn the side desk right side up and place it on top of the existing desk, so the wooden dowels rest on the existing desk. Make pencil marks on the existing desk where the wooden dowel ends hit it. Drill eight holes in the existing desk without the drill going through the surface of the desk. Apply wood glue in the holes. Slide the side desk wooden dowels into the drill holes and apply pressure so the side desk becomes attached to the existing desk. Let the glue dry completely before using the new corner desk.