When measuring for decorative shutters, there is one important question that needs to be answered. Are you looking for decorative shutters that add color and personality to your home, or are you looking for ones that also look like they could close over the window (even though decorative shutters will not)? This question is important, as it determines whether or not you can use a single size for all windows.
One other important thing to keep in mind is architectural uniformity. Different areas have different standards of curb appeal, as architecture is a regional science. In some areas, 12 inch wide shutters are the common choice, regardless of window size. In others, shutters that fit the glass of the window, but not the trim, are the norm. The most common style, however, is to measure the height of the window trim and install shutters that match. The best advice that can be given is to take a trip around your area, making note of the common styles of shutters on homes that are similar to yours. On the rare occasion that there are no homes in your neighborhood with decorative exterior shutters, the rule of thumb is to base the shutter size off of the entire height and length of the window's trim.
In most cases, the height of decorative shutter that is most appropriate is from the top to the bottom of the window trim. If there is a sill at the bottom of the window and you are installing vinyl shutters, it is important to leave a gap of at least 1/4 inch to allow the vinyl material to expand and contract. This of course does not apply to other shutter materials.
In choosing the width of your exterior shutters, you should take into consideration the width of the window and the distance the windows are spaced apart. It is generally best to find a single width that works for all of your windows. The width that usually works best is between 25% and 33% of the total width of your window including the window trim.
If you prefer to make your outside shutters look like they will close over the windows, find a width that is close to 50% of the size of the glass and window frame only, excluding the window trim.
Width of your Windows
|Recommended Shutter Width|
|24" and below||
|24" to 28"||12"|
|28" to 36"||12" , 14 1/2"|
|36" to 40"||14 1/2"|
|40" to 43"||14 1/2" , 16 1/2"|
|43" to 48"||16 1/2"|
|48" to 50"||16 1/2" , 18"|
|50" and above||18"|