How to Construct Window Boxes


Windows boxes places under street facing windows add elegance to a home and make an eye-appealing appearance. Save money by making your own window box out of basic supplies found at hardware or home supply stores. Place a plastic liner inside the finished box to lengthen the life span of the box. Plant hanging or drooping flowers along the front of the window box to maximize the amount of blossoms that adorn the front of the home.

Step 1

Calculate the length of window to fit under the window. It is better to have a box slightly longer than shorter for aesthetic reasons. A common length is 36 inches, to fit a standard window. Use two window boxes for double-wide windows.

Step 2

Cut the front and back window box panels to 36 inches by 6 inches. Cut the bottom panel to 36 inches by 8 inches. Cut the side caps to 6 inches square. Sand the wood panels to smooth rough edges.

Step 3

Drill three drainage holes into the bottom panel at a diameter of 1/2 inch. Pre-drill holes into the each corner of the front, back and bottom panels at a distance of 1/2 inch from the edge.

Step 4

Glue the front and back panels to the side caps with wood glue. Attach the panels together by drilling screws through the corner holes.

Step 5

Glue the bottom panel to the assembled frame with wood glue. Attach the bottom panel by drilling screws through the corner holes.

Step 6

Stain or paint the window box once the glue dries. Apply polyurethane sealer to protect the wood and increase the life span of the box. Do not seal cedar wood window boxes or those painted with an oil-based product.

Step 7

Drill a 1/2-inch diameter hole through each of the back panel top corners, 1-and-1/2 inches from the side of the box. Hold the box under the window and mark the attachment hole locations on the wall with a pencil.

Step 8

Drill a 1/2-inch diameter hole into the side of the home at each marking. Screw a hanger bolt into each hole, leaving 2 inches protruding from the home.

Step 9

Attach the window box under the home window by sliding the protruding hanger bolts through the holes on the back panel. Secure the window box by placing a washer on the hanger bolt and tightening a nut on the end.

Things You'll Need

  • 2 planks,1 inch-by-8 inch
  • Saw
  • Sand paper
  • Drill with bits
  • 12 1-1/3 inch screws
  • Wood glue
  • Paint or stain
  • Paintbrushes
  • Polyurethane sealer
  • Hanger bolts with washer and nut


  • Home Tips: How to Build a Cedar Window Box
  • Western Red Cedar Lumber Association: Planter Window Box
Keywords: make window box, build window box, construct window box

About this Author

Jennifer Loucks has been writing since 1998. She previously worked as a technical writer for a software development company, creating software documentation, help documents and training curriculum. She now writes hobby-based articles on cooking, gardening, sewing and running. Loucks also trains for full marathons, half-marathons and shorter distance running. She holds a Bachelor of Science in animal science and business from University of Wisconsin-River Falls.