Since an outside mount covers the entire window opening and frame, you'll need to add a few extra measurements to ensure your order is the right size.
Measuring the Width
- Measure the exact width (left to right) of the inside edge of the window frame in three places (top, middle, and bottom).
- Record the largest width of the three measurements.
- If you are getting an increment of 1/16” or 1/32”, round up to the nearest 1/8”.
- You will add the frame dimensions to this size.
Measuring the Height
- Measure the exact height (top to bottom) of the window opening in three places (left, center, right).
- Record the largest height of the three measurements.
- If you are getting an increment of 1/16” or 1/32”, round up to the nearest 1/8”.
- You will add the frame measurements to this size.
To mount directly around the window opening, use the inside measurements and add the following to the width and height:
- Faux Wood
- Standard L Frame: + 4”
- Casing Frame: + 5 1/2"
- Wood
- L-Frame: Add 2" as a minimum, but do not add more than 4". If there’s a sill, only add a maximum of 2” for height.
Make sure there’s enough flat surface clearance on all four sides of the opening to accommodate the frame. If there’s a protruding window sill at the bottom, add half of the required height additions.