Where to Mount Your Blind

Before you measure, consider whether you want to mount your window blinds inside the window frame or outside the window on the wall or trim.

• An inside or recessed mount hangs inside the window frame. The top of the blind does not project out of the window opening and provides a   neate, more finished look without hiding wood trim.

• An outside mount hangs either directly on the wood trim or above and outside the wood trim on either side. In either outside mount situation, your   wood trim is covered when the blind is closed. Although an inside mount is usually preferred, an outside mount can make a window appear larger,   hide unattractive windows or provide total light control.

• In addition to personal decorating preference, consider that for an inside mount, your casing or sill must have a minimum depth of 4cms for 25mm   blinds to be totally recessed.

Important Things to Remember

Whether you decide to mount your blind inside or outside of the window frame, here are common guidelines that will help you ensure that your blinds fit properly:

1. Always use a metal tape measure. Cloth or plastic may stretch providing inaccurate measurements.
2. Record measurements in centimeters for accuracy.
3. Record measurements width first, height second (W x H). Be careful not to transpose measurements.
4. Measure the exact width of every window in three different places (top, middle and bottom). Use the narrowest measurement and write it down.
5. Measure the exact height from the top of the window opening to the bottom sill in three different places (left side, center and right side). Use the     longest measurement for all products except vertical blinds (use the shortest height for vertical blinds). Write down the appropriate measurement.
6. For inside mount blinds, the finished width will be made slightly smaller (Approx by 1cms) than your measurements to allow for operating     clearance. The deductions are made so that the blind will not rub on the window frame. There are no deductions taken for outside mount blinds,     these will be made to your exact measurements.
7. Measure all windows, even if they look alike.
8. Double check all measurements. Your blinds will be made for your specific window size, so be sure that they will fit properly.
9. If necessary, request extension brackets to clear obstructions or hold-down brackets for door applications.

Measuring for Venetian Blinds

For an inside or recessed mount :


Measure the exact width of the window opening from the inside of the trim to the inside of the trim on the other side. As some windows are not a perfect square, take this measurement in three places (top, middle and bottom). Round the measurements down to the nearest 1 cms and record the narrowest (smallest) measurement on the measuring worksheet. The headrail of all inside mount blinds will be made slightly smaller (approx 1 cms) than requested to allow room for mounting brackets and for operating clearance.

Measure the exact height of the window opening from the inside of the trim to the top of the windowsill or to the exact length that you want the blind. Measure the height in three places (the right side, the middle, and the left side of the window and take the Maximum height.

Measure the available depth of your window frame. Be careful not to include inside trim, window cranks or tracks. Measure only the space that is available to install the mounting brackets for the blinds. Record the measurement on the measuring worksheet.


For an outside mount:

Outside mounts hang outside the window opening either on the wood trim or above and on either side of the wood trim.

If you want to mount your window blinds directly to the window frame, then measure the exact width of the wood frame itself from outer edge to outer edge and record it on your measuring worksheet.

Measure the exact height from the outer edge of the top of the trim to the top of the windowsill or to the exact length that you want the blind. Measure the height in three places (the right side, the middle and left side of the window) and record the actual height on your measuring worksheet.

If you have enough room on each side of your window and would like to ensure maximum privacy and minimum light gap, measure the exact width beyond the wood trim that you would like to have the blind cover. With horizontals or wooden blinds, it is generally recommended to add at least 5 cms beyond each side of the window and at least 5 cms to the height to allow space for mounting brackets above the opening of the window and to add your desired overlap at the bottom of the window opening.

Measuring for Vertical Blinds

All vertical blind vanes rotate. They also draw like draperies. You may request a center open/two-way draw where the vanes stack on both sides of the window, or a one-way draw where the vanes stack on either the left or right side of the window. For a sliding glass door (ie. patio doors), we suggest a one-way draw with the stack on the opposite side of the door handle.

Most vertical blinds are mounted outside of the window frame because they usually require at least 12 cms in window opening depth. Patio door handles protrude and interfere with an inside mount. However, if you have sufficient window depth, they can be mounted inside the window frame.

For an inside or ceiling mount:

Depending on the size of the window, an inside mount will result in the window glass being partially covered by the stacked blinds when they are opened.

Measure the exact width of the window opening across the top where the headrail is to be installed. Measure from the inside of the trim on the left side to the inside of the trim on the right side. Round the measurement down to the nearest 1 cms and record this measurement on the measuring worksheet. The headrail of all inside mount blinds will be made slightly smaller (Approx by 1 cms) than requested to allow room for mounting brackets and for operating clearance.

Measure the exact height of the window opening from the inside of the trim to the top of the windowsill or to the exact length that you want the blind. Measure the height in three places (the right side, the middle, and the left side of the window). Round the measurements down to the nearest 1 cms and record the shortest (smallest) measurement on the measuring worksheet. The blind will be made about approx 1 to 1.5cms shorter to allow for free movement of vanes at the sill or floor.

Measure the available depth of your window frame. Be careful not to include inside trim, window cranks or tracks. Measure only the space that is available to install the mounting brackets for the blinds. Record the measurement on the measuring worksheet.

Refer to the Things You Should Know section for the type of vertical blind you have chosen to determine the minimum window depth required to have a recessed mount where the blind does not project out of the window opening.

For an outside or wall mount:

Depending on the amount of wall space available, you can have the blinds stack completely off the window glass when they are opened.
Measure the width of the window opening including trim. If there is room, add at least 10cms to each side for overlap. This will ensure minimum light gap.

Measure the window opening height. Add at least 8 cms in height to allow for mounting brackets above the opening and add your desired overlap at the bottom. If your blinds will hang down to the floor or to the windowsill, deduct at least 1.5 to 2 cms for clearance.

Measuring for Rollup Blinds

For an inside or recessed mount:

Measure the exact width of the window opening from the inside of the trim to the inside of the trim on the other side. As some windows are not a perfect square, take this measurement in three places (top, middle and bottom). Round the measurements down to the nearest 1 cms and record the narrowest (smallest) measurement on the measuring worksheet. The headrail of all inside mount blinds will be made slightly smaller (approx 1 cms) than requested to allow room for mounting brackets and for operating clearance.

Measure the exact height of the window opening from the inside of the trim to the top of the windowsill or to the exact length that you want the blind. Measure the height in three places (the right side, the middle, and the left side of the window) and take the Maximum height and Add 10cms more for a build in valance for an added elegance.

Measure the available depth of your window frame. Be careful not to include inside trim, window cranks or tracks. Measure only the space that is available to install the mounting brackets for the blinds. Record the measurement on the measuring worksheet.

For an outside mount:

Outside mounts hang outside the window opening either on the wood trim or above and on either side of the wood trim.

If you want to mount your window blinds directly to the window frame, then measure the exact width of the wood frame itself from outer edge to outer edge and record it on your measuring worksheet.

Measure the exact height from the outer edge of the top of the trim to the top of the windowsill or to the exact length that you want the blind. Measure the height in three places (the right side, the middle and left side of the window) and take the actual height and Add 10cms more for a build in valance for an added elegance.

If you have enough room on each side of your window and would like to ensure maximum privacy and minimum light gap, measure the exact width beyond the wood trim that you would like to have the blind cover, it is generally recommended to add at least 5 cms beyond each side of the window and at least 5 cms to the height to allow space for mounting brackets above the opening of the window and to add your desired overlap at the bottom of the window opening and Add 10cms more for a build in valance for an added elegance.

How to Measure in Special Situations

Sliding Doors

The most common window treatment for sliding doors is vertical blinds. You can mount verticals, either within the door frame (inside or ceiling mount), or on the wall above the casing (outside mount). We suggest that you allow 8 to 10 cms above the door frame to mount the vertical brackets. Remember, when measuring the width for an outside mount, add a minimum of 10 cms on both sides of the window to prevent light gaps. If your door handle protrudes it could interfere with the window treatment. If necessary you can order extension brackets. These brackets add depth to the headrail, allowing the clearance for the obstructing door handle.

French Doors

These doors are very simple to measure. To prevent against light gaps, measure the width of the glass pane and add as much as available without interfering with the door handles. Usually you can go at least 2 cms on either side. It would be ideal to be able to add 5 cms on each side, adding a total of 10 cms to the width. Allow room for mounting hardware (Approx 10 cms) at the top. The length of the blind should be measured 5 to 8 cms below the glass to ensure that the entire glass is covered.

Please Note: When you order a certain width, you are ordering the width of the headrail. The blind itself (fabric, metal slats, vanes) will always be narrower than the headrail to allow it to fit inside of the headrail. This difference is generally not significant. However, in the case of roller shades that are outside mounts, the fabric will be 3 cms narrower than the headrail. So, you will need to add an 3 cms to your measurement to ensure that the fabric will cover the window opening.

Sill depth

For inside or recessed mounts, you need to take into consideration the amount of window depth you have to work with. Depending upon the product, mounting depths vary, consult the Things You Should Know section for the product you are interested in.