Creating window cornices


The plain-looking interior can be made more appealing by adding cornices

The plain-looking interior of a recreational vehicle can be made more appealing by adding cornices to decorate the top of windows. The cornice has a box shape and is upholstered by any fabric which can be matched to draperies and pillows.


Here’s an easy project for turning a plain-Jane RV interior into a designer’s dream come true

Do you consider your RV interior a little plain? Could it use an ornamenting touch? One simple way to perk up the interior is to add cornices. A cornice is a treatment used to accent the top of a window, usually installed to camouflage drapery hardware. Its box shape adds dimension and definition to RV windows.

In some RVs, cornice boxes are a standard feature. If you already have them, consider recovering the boxes yourself, rather than having them done by a professional upholsterer. If your RV doesn’t have cornices, you can build and cover them yourself with a minimal amount of tools and material.

If your RV doesn’t have cornices, you can build and cover them yourself with a minimal amount of tools and material

Almost any fabric is suitable for upholstering a cornice box. Extra fabric can be purchased for slipcovering accent pillows, and matching tiebacks can be added to any draperies that are already in the vehicle.

Before beginning, check to make sure you have enough room for the cornice. Your box can be as shallow as 1 1/2 inches and have the same effect as a box that is 3 to 4 inches deep. The unit will need to be mounted in some manner to the wails: L- or angle brackets are usually used, or you can mount the cornice directly under and onto the overhead cabinets.

Figure 2 shows how a cornice box is put together. Before upholstering the box, consider adding a 1/4- to 1/2-inch piece of foam padding to the front face only. This will give your finished cornice box a little depth and make it look quite professionally done.

Figure 3 shows different styles from which you can choose for the front face of the cornice. Consider your own skill level at cutting wood before choosing the shape. Of course, you can show off your individual style by creating your own design.

You will need to measure each window that you intend to cover with a cornice. The following information is a good guide for taking measurements.


When measuring the width, the inside finish measurement should be at least 1 inch wider than any existing window treatment, such as miniblinds, woven woods or draperies, and the hardware. As shown in Figure 2, the return (or side) of the cornice is mounted to the outside ends of the front face and header platform, creating a box that would be a half inch larger on the outside than the inside of the box when using 1/4-inch plywood.


There are many ways the bottom edge of the front face of the cornice can be shaped. It does not have to be plain and square, but remember, if you do decide to scallop this edge, the shortest height measurement should be no less than 2 1/2 inches. This ensures that you will be covering any drapery hardware that might exist.


Depth is also known as the return. When measuring out from the wall, look at any protruding items, such as the control wand on a set of mini-blinds. To work correctly, the wand requires room to operate, as do the pulls on blinds and woven woods. Draperies also need to move freely when opening and closing. A cornice box that’s made too shallow will only frustrate you.


To figure the yardage required for your cornice, you will need to know the width of each box plus the return depth on each side. Add these measurements together, and then add an extra 2 inches to each side for wrapping around the box’s edges and under the inside of the box for stapling.

For the height of the fabric, you will need to add the height of the front face to the depth of the header platform. To that measurement, add another 4 inches for wraparound and stapling.

Upholstery fabrics are woven 54 inches wide; most dress-good fabrics are 44 to 45 inches wide. Whatever fabric you choose, you will need to cut out the fabric panels to cover the cornice along the fabric’s selvage; capped “railroading,” cutting your fabric panels along the selvage enables you to cut the full width needed without having to piece or seam a narrow fabric.

For example, the longest width you need to cover the cornice that goes across the rear window of your RV is 84 inches. Divide 84 by 36 inches, and you see that you will need to purchase 2 1/2 yards of fabric. Figure 1 shows how to mark and cut out the fabric panels needed to cover three or four cornices, each a different size in width.

That’s all there is to it! Expect your project to take about six hours – a nice weekend enterprise that you can enjoy for years to come.



(1) Mark and cut out wood pieces to desired size.

(2) Mark the center of the header platform and front face. This will help guide you when it is time to upholster the cornice.

(3) Pre-drill any screw holes needed for mounting.

(4) Staple or nail wood pieces together; assemble as in Figure 2.

(5) Cut a piece of foam padding to cover the front face of the box. Staple or glue the foam pad with 3M’s 08080 canned spray adhesive. Trim the foam with a safety razor so it’s even with the wood edges.

(6) Mark and cut out the fabric panel, as in Figure 1. Mark or notch the fabric panel at the center of the width.

(7) Lay the fabric panel face down on your work table. Set the box on top of the fabric panel, lining up the center notches with the center lines on your cornice. Position the box so that fabric panels wrap around the head platform and front face, leaving 2 inches of fabric on both sides for stapling.

(8) Upholstering is like gift-wrapping a box, except that you are working with flexible fabric instead of stiff paper. And of course, you are using staples to secure the fabric instead of tape. The best place to start upholstering is at the center, pulling the fabric around the header platform and around the edges to the back or inside of the cornice [ILLUSTRATION FOR FIGURE 5 OMITTED]. Apply one or two staples to hold the fabric in place. Then, pull the fabric around the front face and around to the inside of the cornice, and staple once or twice.

Next, pull the fabric around each return, and staple once to hold the material in place. Pull the fabric firm enough to eliminate any wrinkles or puckers that might appear while working with the fabric. Going back to the top header platform, staple down the remaining fabric, working from the center toward the ends. Stop stapling within 6 inches of the end return. From there, staple every 1/2 to 1 inch.

Now, staple the fabric around the front face, starting at the center and working your way to the end returns. Smooth out any wrinkles, and pull the fabric firm enough to create a smooth and even edge. Again, staple every 1/2 to 1 inch.

If you are upholstering a cornice box with a scalloped front face, be sure and clip the fabric to release any tension that you might be experiencing while working. Figure 4 shows where the fabric should be clipped and where it can be folded or overlapped and stapled. Staple within 6 inches of end returns.

Figure 5 shows how to fold in the excess fabric at the returns. It is not necessary to cut away any fabric unless it is a heavy, thick material. If you feel you need to remove excess fabric, remember not to leave a raw edge exposed. The fabric will eventually fray and look unfinished. Always fold under a raw edge and staple it down to prevent it from coming loose.

Use your fingers to tuck in the excess material. To get a sharp edge into the corner of the box, use an awl or seam ripper to help hold the folded fabric in place while stapling. Finish stapling the fabric around the return. Excess fabric can be removed from inside the box if necessary, Repeat on opposite return, and you are ready to mount your cornice.

(9) Locate your pre-drilled screw holes with an awl. With a razor-blade utility knife, remove the fabric covering the holes. This prevents the fabric from twisting around the screw while the cornice is being mounted.