Measuring guide
How to measure for cassette roller blinds
A cassette closes the light gaps around a roller blind: a headboxThe box across the top of a cassette system. It encloses the roller. across the top encloses the roller, and channelsThe track each side (and along the bottom) that the fabric runs in, closing the light gaps. run down each side and along the bottom. This guide covers recess-fit and face-fit cassette systems, for windows with or without architraves. Measure in millimetres (mm), record the width first and then the drop.
Before you measure
How is a cassette system ordered?
Order the roller blind and cassette system together. This system fits our compatible roller blinds only and cannot be retrofitted to an existing blind. The factory adjusts the blind and shortens the base rail to fit inside the cassette.
Which roll direction?
Select under-roll, with the fabric running behind the tube. Use the same measured size for the blind and its cassette.
What should I check first?
Check that there is space for the headbox and channels, and that a projecting bottom sill will not interfere.
How should I measure?
Use a metal tape measure, a pencil and our worksheet. Record the width first, then the drop, in exact millimetres (mm). Do not round, use a cloth tape or copy dimensions from house plans. Measure every window separately, even when windows look identical.
If you are measuring with someone else, repeat each reading aloud as it is written down. Check every measurement and order detail twice, then a third time.
Do I make any deductions?
For ordinary recess measurements, do not make factory deductions yourself. Special-window instructions must be read with the product guide; ask us to resolve any conflict before ordering.
Choose your fit
Choose your mounting type
Recess fit (inside the frame)
A recess fit places the headbox and channels inside the window opening.
- Needs at least 50 mm from the nearest obstruction to the front of the opening
- Can leave a small overall gap: see step 3
Face fit (on the architraves)
A face fit places the system on the architraveThe timber trim fixed around a window frame..
- Follows the regular face-fit roller method
- Decorative mouldings must not prevent the headbox and side channels sitting flush
- The simpler alternative if recess gaps are a concern
Face fit (no architraves)
On a square-setA window with no architraves: the plaster or wall lining finishes square at the edge of the opening. window (no architraves), the system sits on the wall around the opening.
- Needs 101 mm above the opening for the headbox
- Needs at least 50 mm at the left, right and bottom for the channels
Measure step by step
Take every measurement in millimetres (mm).
Check the mounting type before you measure
Recess fit (inside the frame)
Step 1: Check the depth
Allow at least 50 mm from the nearest obstruction to the front of the opening.
Below 90 mm depth, the headbox will project slightly into the room; it has side covers.
Not enough room? instead.
Step 2: Measure the width and height
Measure the width at the very top, middle and very bottom of the opening; use the smallest. Measure the height at the far left, centre and far right; use the smallest.
Give those same measurements for both the cassette and the roller blind.
Do not deduct again.
Step 3: Understand the recess gap
A recess system may leave an overall width or height gap of about 2 mm or more. Squareness can increase it. Full blackout may require no-gap silicone, or a small timber quadA small quarter-round timber strip, fixed in the corner behind a channel. behind the channels.
Top-and-side-only systems are somewhat easier to install. Face fixing is the simpler alternative if this is a concern.
Face fit (on the architraves)
Step 1: Measure as a face-fit roller blind
With a timber architrave, follow the regular face-fit roller method: measure across the outside edges of the architraves at the top, then the drop from the top of the architrave. See the roller blind measuring guide.
Decorative mouldings must not prevent the headbox and side channels sitting flush.
Step 2: Check the bottom sill
Check that a projecting bottom sill will not interfere with the channels.
Face fit (no architraves)
Step 1: Allow room around the opening
For square-set windows without architraves, add 101 mm above the opening for the headbox, and at least 50 mm at the left, right and bottom for the channels.
Step 2: Top-and-side-only channels
For top-and-side-only channels, extend the blind further below the opening for light blockage. Confirm the additional drop for your opening with us before ordering.
Step 3: Check the wall and sill
Check that the available wall area and the bottom sill permit the planned system.
Before you order
- Label your measurements “Width” and “Drop”, in that order, so they cannot be mixed up.
- Give only the exact measurements asked for. Your blinds are made to your measurements.
- Give the same measurements for the blind and its cassette; do not deduct again.
- Measure every window separately. Windows that look identical can differ slightly in size.
- Every home is different. If you are unsure about any part of measuring, contact us or call 1300 011 561, or send us your readings and a photo.
