Outside-Mount Shutter Measuring: Step by Step

Outside-mount shutters sit on the face around the window, so you take the area the frame will cover rather than only the internal recess. Use that result for this step.

In this article

• Measuring for an Outside Mount
• Outside Mount — Square-Set Window
• Measuring Outside Mount with an Architrave
• Outside Mount — Window with Sill
• Outside Mount — Window with Sill and Architrave

Outside-Mount Measurements

An outside-mount shutter sits around the opening rather than within the recess. The reference points change depending on whether the window is square-set, surrounded by an architrave, fitted with a sill, or has both an architrave and sill.

For the outside-mount methods below, you will generally work from the largest of the three readings so the shutter frame fully covers the opening.

Outside Mount: Square-Set Window

A square-set window has no timber architrave surrounding the opening.

Begin with the inside edges of the square-set opening, then apply the specified shutter-frame allowance around those dimensions.

• Take three separate drop readings.
• Take three separate width readings.
• Work from the largest width and the largest drop.

For the order, without a protruding sill, add 42mm on every side. That adds 84mm to the overall width and 84mm to the overall drop.

As you work through the guide, with a protruding sill, add 42mm at the left, right and top only. The total addition is 84mm to the width and 42mm to the drop.

Outside Mount: Window with Architrave

Because many windows have an architrave, this is a common outside-mount method. Treat the outer architrave edges as the measurement boundary.

• Take three height readings from the outer edge of the lower architrave reference to the matching outer edge above.
• Take three width readings from the outer architrave edge on one side to the outer edge on the other.
• Submit the largest width and largest height from the readings taken.

Outside Mount: Window with Sill

Use the top surface of the sill as the lower height reference.

• From the sill, take three height readings to the upper outside-mount reference point.
• Measure width in three places.
• Submit the largest width and largest height from the readings taken.

At this stage, for a protruding sill, add 42mm at the left, right and top. This increases the width by 84mm and the drop by 42mm.

Outside Mount: Window with Sill and Architrave

For a window with both sill and architrave, start the height from the top of the sill and use the outer architrave edges for the top and side reference points.

• Take three height readings from the sill to the outer edge of the upper architrave.
• Take three widths between the outer left and outer right architrave edges.
• Submit the largest width and largest height from the readings taken.