Window treatments are installed inside the window casing.
INSIDE MOUNT
1. Measure Depth:
A minimum 4 1/2 inches depth is required for ceiling mounting brackets. Please leave at least extra 1 1/2 inches flat space if you install it close to wall for slats tilting. If you have a door handle, make sure there is enough depth in front for mounting.
2. Measure Width:
Measure inside width of your window across the top, middle and bottom separately, choose the smallest one.
3. Measure Height:
Measure the height of window openness from top to sill across right, middle and left, record the narrowest one.
Note: Vertical blinds will have no deductions taken at the factory. They will be made according to your exact measurements.