How to Make a Pelmet Box

Associate Editor Kaylei McGaw tackles this easy DIY window upgrade

A girly, New York City nursery with a DIY pelmet box over the window
A girly, New York City nursery with a DIY pelmet box over the window

Decorating in a small space—even when it's for a small person, like this one is—presents a multitude of challenges. One of the greatest is creating a sense of sophistication and permanence without overwhelming the space. I recently transformed this small nursery in Manhattan's Greenwich Village, and found that one element that really helped to elevate the room was a pair of DIY pelmet boxes for the windows. At first, I considered making draped valances, but as I started researching, I realized that pelmets had a more basic structure that I could easily build myself with affordable materials. I was talking out my idea with Lonny designer Natalie Caceres, who tipped me off that Little Green Notebook blogger and DIY impresario Jenny Komenda had done almost exactly that. After seeing that Komenda used light foam core board rather than plywood, I was completely sold on the idea. I modified the shape to suit the narrow window, and have included my modified measurements below. If you take on this project, share your own versions with us on Instagram, @LonnyMag! 

DIY Pelmet Box

What You'll Need:

-(1) 30" x 40" x .75" piece of foam core board

-a yard stick or ruler

-a pencil

-an x-acto knife

-push pins or tacks

-a staple gun


-duct tape


1. Measure the width of your window to the outside edge of the frame and add 4 inches (the nursery windows were 32" wide so my pelmet width was 36")

2. Draw a rectangle on your poster board that is that width, and 10" tall. Cut it out with the x-acto knife. This is the front/face piece of your pelmet.

3. Draw and cut out another rectangle that is the same width and 5" tall. This is the top edge of the pelmet. 

4. To create the side edges, draw and cut out two 10" x 5" rectangles.

DIY Pelmet Box

5. Next, shape the face piece. Measure and mark a line at the center of the longest width. Use a large round object (I used a dinner plate) to draw 2 smooth curves from the center to the bottom edge. Cut the edge. 

6. Tape the corners together with duct tape.

7. Cut a piece of fabric that is at least 25" x 50". If you're using a patterned fabric, align the repeat so that it's straight, and begin to tack it in place from the center, outward. I used thumb tacks first, and once I was happy with the way the fabric was laying and it looked smooth, I secured it permanently with the staple gun. 

8. Since the box is so light, you can hang it with two straight nails at the corners, or with small L-brackets

DIY Pelmet Box

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