Close view of a measurement scale


  • These treatments can add interest to a window or space that may not need full coverage (such as a leaded glass window) with a drapery or shade.
  • There are several shapes and contour lines available that will give depth to simple fabrics.
  • Can give height to the window and the entire space
  • Work best over windows that are at least 4” below the ceiling line


  1. Begin by measuring the width of the window from the outer most edges of the framing. Also measure the distance from the top of the window to the ceiling line or crown moulding.
  2. It is suggested that cornices and valances be made at least 4” wider than the entire window space so that the window does not look crowded.
  3. If you are putting a valance or cornice over a drapery or roman shade, you need to consider the absolute width of your other window treatment.  Valances and cornices need to be at least 4” wider than a drapery treatment to allow for hardware space.
  4. If your valance or cornice board is going over an inside mount roman shade, you need to add 4” to your window width from the outside edges of the window framing.
  5. To calculate the depth of the valance or cornice board, consider any window treatments that are already present.  Most valances will be at least 3” deep to allow for mounting hardware.
Drape Measuring Illustration
Valance Measuring Illustration