How to Make a Window Cornice

When I was designing my kitchen I decided to go with the classic subway tile backsplash. On one wall I have a window directly over the kitchen sink – so I thought extending the subway tile to the ceiling would be great idea so things didn’t look so choppy. While I loved the end result – something still was missing.

Adding a cornice to the window seemed like a possible solution but I wasn’t sold on the idea. Therefore…I didn’t want to invest a lot of money into this project. And I didn’t want to screw holes into my tiled wall to install the cornice.

Solution – constructing the cornice frame with poplar boards (total $30) and attaching the cornice to the inside top frame of my window instead of my tiled wall.

Here are the plans to build, upholster and install a DIY window cornice.

Materials

(2) 1 x 3 inch x 8 foot poplar board
(1) 1 x 2 inch x 8 foot poplar board
Miter Saw
Cordless Drill
Screws
(2) 2-Inch Double Wide Corner Brace
1/2 yard of battening
1/2 yard of fabric
Heavy Duty Staple Gun
1 inch Upholstery Tack Nails
Masking tape
Small hammer

The kitchen window pre-cornice…

How to Make a Window Cornice

The two 1 x 3 inch x 8 foot boards will be used for 4 different parts of your cornice. The first cut will make Board A. Measure and cut the first 1 x 3 to fit the inside length of the window frame. The inside of my window frame (head jam) measured 37 inches.

How to Make a Window Cornice

Using the second piece of 1 x 3 board – cut the board to your desired cornice length. This board will become, Board B. My “Board B” is 45 inches. You will want to make an “L” shape with Board A and Board B. Make sure Board A is centered so there are 4 inches on each side of Board B. Use two 2-Inch Double Wide Corner Brace to secure boards together on the outside of the “L” shape. See picture below.

How to Make a Window Cornice

Next, cut two pieces of 1 x 3 inch board to your desired cornice height. My cornice measures 14 inches tall. These two 14 inch pieces will now become the vertical “sides” of your cornice.

Measure and mark 4 inches up from the bottom of each vertical “side” piece. Attach “Board B” to the inside of the “side” piece at the 4 inch mark. This will allow the cornice to sit 4 inches below the window frame and 10 inches above the window frame. See picture below.

How to Make a Window Cornice

Next, using the 1 x 2 inch board, cut 2 pieces to the same measurement as Board B. In our case that was 45 inches. Attach the first 1 x 2 board to the top, outside part of each vertical “side” piece. Attached the second 1 x 2 board to the bottom, outside part of each vertical “side”. See picture below.

How to Make a Window Cornice

The “L” shaped piece (Boards A and B) will attach to the top, underpart of the window frame. The outside rectangle frame will be the cornice. Eventually, this frame will be upholstered with batting and fabric.

How to Make a Window Cornice

Next, using a Cordless Drill and two 1.5 inch screws – secure “Board A” into the top underpart of the window frame (not the trim). We did this to make sure that the frame fit in the designated area and that it was level. It also gives you a better idea of how the cornice functions. Remove to begin upholstering the frame.

How to Make a Window Cornice

In order to give the cornice an upholstered look you will need to line the frame with batting. This can be picked up at any fabric store.

How to Make a Window Cornice

Trim batting so there is at least 1/2 inch of excess around the entire frame.

Pull batting taut and staple to the frame.

Next, repeat this process with a fabric of your choice. We went with a heavy-duty white basketweave print. Pull fabric taut and secure with staples.

Since the fabric was plain – we wanted to add some detail to the cornice. We decided to add 1 inch Upholstery Tack Nails to the top and bottom of the cornice.

How to Make a Window Cornice

Place a piece of masking tape across the very top and bottom of the cornice. This will act as a guide for your 1 inch nail tacks.

How to Make a Window Cornice

Start in the center of your cornice. Place the tacks on the bottom edge of the masking tape (not on the tape) when working on the top row. When working on the bottom row – place the tacks on the top edge of the masking tape. Gently press a tack into the fabric. Use a spacer to insert the next tack. This will help keep the spacing between each tack the same along the top and the bottom.

There was some trial and error when lining up the tacks. Just play around with them until you like the spacing and look. Once you have them in place remove the masking tape. Then use a small hammer to secure them into your wood. You can also just press them down hard with your fingers.

How to Make a Window Cornice

Using the existing screw holes, in “Board A” reattached Board A into the top, underpart of your window frame.

One Comment Add yours

  1. Diane says:

    They look amazing! Great inspiration! Just ordered the tacks!

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