Outside-Mount Measuring for Square-Set Openings

A square-set window has no separate architrave, so an outside-mounted shutter fixes directly to the wall face around the recess. Use that result for this step.

In this article

• Outside Mount — Square-Set Window
• Outside Mount — Window with Sill

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 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.