How to Design a Fake Transom Window

Measure the width of the window or door you will put the fake transom window above. This is the width of the transom.

Set a compass to half that distance. For instance, if your door measures 18 inches across, set the legs of the compass 9 inches apart.

Fit a glass marker into the compass.

Draw a line across a mirror the same width as the transom. For instance, if your door measured 18 inches across, the line for the base of the transom will also measure 18 inches across.

Place the pointed leg of the compass at the midpoint of the line. Draw an arc connecting the two ends of the line to make the half-circle transom shape.

Cut the semi-circle shape out of the mirror with a glass cutter.

Paint a line around the edge of the mirror and add three rays from the center of the base of the mirror to the arc. This creates the illusion of window panes on your mirror. Wait for the paint to completely dry before hanging the mirror. You might also want to use light colors to create a stained-glass illusion on the mirror.

Drill three pilot holes for the screws for the j-clips at the top of the door frame, evenly spaced along the length of the frame. For an 18-inch wide door, place the holes for the j-clips every 6 inches.

Attach the three j-clips to the wall with the three screws.

Spread mirror adhesive on the back of the mirror and press the mirror to the wall above the door so the base of the mirror rests on top of the j-clips.

Place an optional battery-operated picture light at the base of the mirror with the light pointing toward the ceiling to make your fake window transom look like it is letting in sunlight.