Box windows are measured for shutters in a similar way to angled bay windows using the same small or large L frame. Instead of meeting at a 45° angle, the frames meet at 90° right angles, butting up to each other.
The box window in picture 1 below is made from wood and as such the handles do not protrude. This allows the frame to be fitted tight to the window frame where 2 1/2″ louvers are chosen (assuming there are no obstructions such as alarm boxes). As with angled bay measuring, space out 5/8″ if 3 1/2″ louvers are chosen and 1 1/2″ if you’ve chosen 4 1/2″ louvers. Picture 2 shows you how the actual frames will fit into the openings prior to fixing.
If you need any assistance when measuring your box window, please call us on 917-284-9425.