The amount you add depends on how far to the side of the window you want the curtains to hang.
Using one curtain panel per window.
Usually curtains are hung in pairs but an asymmetrical look can be very attractive and so you may want to hang only a single curtain panel.
Several single panels can be combined to curtain an extra wide window.
Can be a roman shade style or hanging straight down from the bar and pair them up with two windows to draw the eye to the center of the wall.
They can be hung with the tie on the right or the left of the window.
Another option for a room with two windows is to pull both panels to one side and hold in place with a tie back.
So no i don t recommend it.
Measure the width of the curtain rod if you have chosen it.
If you are splitting up a pair and only using one on a window i think it will look even skimpier.
Most of the time curtains come in pairs.
Yes i think a room s look can be ruined by the use of skimpy curtains.
Yes one drapery panel per window would look out of place.
For smaller windows where a double curtain will just be too much a single curtain panel is a much more elegant choice.
Usually the drapery panels should equal two and a half times the window width.
One panel per window will look very skimpy and certainly.
For example the left curtain panel should be drawn to the left and the right curtain panel should be drawn to the right.
A single panel may also be more cost effective for.
Long panels should look as if they are full enough to pull across the entire window.
One curtain panel on a window would look funny to me unless you could tie it back on one side but it would need to balance out with the other windows.
For covering windows however single panel drapes have a variety of uses.
If you haven t chosen one measure the width of the window and add 1 to 3 inches for each side of the window.