This blind is installed outside the window frame.
With Architrave; take the external width measurements, including the architrave
Without Architrave; take the width of the opening and add an extra 100mm
This blind is installed inside the window frame.
Measure from inside the window frame.
Take 3 width measurements to determine if the window is square. Measuring the top, middle and bottom of your window.
If it’s not square, use the smallest measurement.
Once you have selected your mount, measure the length and width of your window so the perfect size blind can be selected for your installation type.