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First measure the width and height of the recess and deduct 5mm N.B. It is advisable to measure both in several places and you should of course quote the minimum.
Now measure diagonally across the recess in both directions. If the recess is more than 15mm out of square, selecting the Z frame option will be more suitable and will require less remedial work.
Full height shutters over 1600mm in height, will require a midrail which adds rigidity to the panels. Please state the position of the midrail by measuring up from where the bottom of the frame will be fixed, to where you require it. This would usually be where there is a transom on the window.
For Tier on Tier shutters measure as standard full height shutter but ascertain the height of the tiers by measuring up from where the bottom of the frame will be fixed to where you require the split of the tiers.
For Café Style, to ascertain the finished height to the top of the panel, measure up from the bottom where the frame will be fixed to where you want the panel to finish.