Swag Valance Curtain Set
Mainly we need two measures from you: width and height of the window treatment. Take the following key measures to help decide the size that best fits.
The distance between the outside edges of window frames. Using the outside edges for the measurement ensures that the window treatment will properly cover the window frames. Window width helps define the minimum width of the curtain set.
The distance between the sides of the walls. This defines the maximum width of the curtain set in the typical situation where there is just one window on the wall. When there are multiple windows on the wall and multiple curtain sets are desired, use the distances between adjacent windows as well to define the wall space surrounding the individual windows.
The height from the top of the window frame to the floor. This defines the minimum height of the curtain set.
The height from the ceiling to the floor. This defines the maximum height of the curtain set.
In general, the width of the valances and curtains could be anywhere between (a few inches over) the window width and (a few inches short of) the wall space.
For a full valance curtain set, you might want to add about 12 inches (6 inches on each side of the window frames) to the width of your window frames to arrive at the width of the curtain set. This way, you can make sure that the window is fully covered by both the drapes and valance.
If the wall space allows, you can make the window treatments wider and more dramatic by adding more than 12 inches. Actually, there is no limit as to how wide the window treatment should be. However, if the wall space is limited (< the width of the window frames + 12 inches), take the wall space (subtract several inches for rod installation) as the width of the window treatment.
For a valance only window treatment (with no curtain panels underneath), you can keep the width of the valance closer to the window width; for example, 6 inches over the window width (3 inches on both side of the window frames).
For a valance curtain set, we usually recommend hanging the valance curtains from (close to) the ceiling to the floor. It will make the room look taller and the window treatment more impressive. That is, make the height of the curtain set just a few inches short of the ceiling height. Furthermore, the height of the curtain panels could be a bit shorter as the valances are usually hang on a higher curtain rod to cover the curtain panels.
However, if the distance between the ceiling and the top of the window frame is more than 16”, the top part of the window frames might show underneath the overlapping swags when the drape panels are tied to the side. Therefore, if your ceiling is quite high or you prefer hanging the valance curtains right above your window frames, you can add 6”-10” to the window height to arrive at the height for the curtain set.
Finally, if you like a formal, puddled look for the curtain drape panels, feel free to add several more inches to the height measurement for the curtain drape panels.