Measuring Guides

Roller Blinds

Measuring for your new blinds will be effortless with our easy-to-follow guide! Keep an eye out for our helpful tips, allow plenty of time, and most importantly, double check everything!

Measuring Standard Windows

The first thing to consider when measuring for your new blinds is where you will be fitting them, inside or outside recess

Soon we will have a couple of handy video guides, which will talk you through the process of measuring standard windows, which differ depending on where you will be fitting your blinds. You can fit either Inside Recess (so the blind will fit inside the window recess, either top fixed or face fixed, and drop down to the bottom of the window) or Outside Recess (so the blind will face fix onto the wall above the recess, oversail the window either side, and drop down as far as you need it to go). If you prefer a written guide over a video guide, or would like to use it in conjunction with the video, scroll down for a step-by-step guide. This will also cover non-standard windows (such as partly tiled recesses and bay windows).

Inside Recess

Measure the full width and height of the recess (some people refer to this as the window reveal) and we will make the appropriate deductions to ensure your new blind fits perfectly.

Measure in 3 places for both the width and the drop. For the width, compare the measurement at the top of the recess with the smallest of the measurements you’ve taken – if the difference between those is less than 25mm, use the measurement at the top of the recess. If it is not, use the smallest measurement.

Don’t make any deductions from this measurement – we won’t deduct anything from the width for roller blinds. We won’t deduct anything from the drop.

Please use a metal tape measure – cloth ones can stretch and give you inaccurate measurements. Remember to double check all measurements!

Top-Tip:

Check that your recess is deep enough to fit the blind into, also bearing in mind any obstructions such as handles. 

When Top-Fixing a standard roller blind from us in the recess, your recess will need to be at least 50mm deep. When Face-Fixing, it will need to be at least 70mm deep.

Don’t forget you can choose the Roll Direction of the blind – whether your roller blind is Standard Roll (rolls down the back of the blind, closest to the glass), or Reverse Roll (the fabric rolls down the front of the blind, away from the glass). This will help you clear projecting handles if you don’t have much room within the recess.

Outside Recess

Measure the full width and height of the recess (some people refer to this as the window reveal) and add as much as you need to the top and to each side, we will make the blind at the size you have specified, there will be no deductions to the width or the drop.

To minimize light leakage, we recommend that the blind overlaps the window recess by at least 70mm at the top and 50mm either side. This is especially important if the blind will be in a Bedroom or somewhere someone is likely to sleep.

Please bear in mind the overall cloth width on a roller blind is 35mm less than the overall blind width. Also ensure that you have considered the Roll Direction of the blind as mentioned in the grey box above. If you choose Reverse Roll, this will increase the gap between the fabric and the wall, meaning more light will come through.

How far you choose to overlap at the bottom is simply personal preference, just make sure you take any obstructions into account, such as radiators.


Top-Tip:

If you are replacing an existing blind with one of the same size, simply measure the blind (including its fittings) and specify ‘Blind Size’, we will make you one the same size.

Measuring Other Window Types

From partly tiled recesses to bay windows, we understand that not everyone will have a conventional square or rectangular shaped window. This is why we have delved deeper into the measuring aspect to include some of these less conventional windows, to ensure these windows are just as easy to measure as others.

Part-Tiled Recesses

If you have tiles part-way up your recess (which is most often the case in kitchens and bathrooms) then the space between the tiles is likely to be the narrowest point in the recess.


Measure at the top of the recess and between the tiles
. Compare the two measurements; if the difference is less than 25mm, use the measurement from the top of the recess.

If the difference is more than 25mm, use the width between the tiles.

This will ensure that the cloth width of the blind does not exceed the width between the tiles, causing it to come into contact with them when the blind is lowered.

 


Top-Tip:

Carry out the same method of measuring if you have a picture rail (dado rail), skirting board or other items on the inside of the recess.

Bay Windows (Angled & Square)

Bay Windows can come in a variety of different shapes and sizes – from square bay windows, to 3, 4, 5 (and sometimes even more) angled bay windows. You may also have a half-bay or L-shaped window, which can be particularly prevalent in buildings which have been renovated and had a dividing wall added between 2 rooms. No matter which type, we can help, simply check the links below to guide you through the process!

The main point to note with roller blinds in bay windows is that, due to the spacing caused by the brackets, there will always be gaps in between the fabric of the blinds where the windows are not covered. This becomes more apparent when the fabric is blackout, as it accentuates how much light there is at the sides of the blinds.

Roller blinds remain a popular choice for all types of windows, including bay windows, but it is always worth considering all of the characteristics of different types of blinds, before making your final decision.

Preparing to Measure – Square Bay Windows

We have detailed 3 options below, which highlight the 3 different ways you can fit roller blinds in Square Bay/Box Bay Windows. After looking the images and reading the measuring details, decide which option you think will suit your bay window best. Consider whether you will be top fixing or face fixing when making this decision.

The allowance you need to make for the brackets when top fixing is 50mm, when face fixing it is 70mm. Bear in mind you will need a flat surface of 50mm to fit the bracket to.

Ensure you always use a metal tape measure to ensure your measurement are as accurate as possible.

Option 1

Option 2

Option 3

Measuring the Width – Option 1

This is the most common method of installation in a box-bay window. The blind runs across the front (or back, depending on which way you are looking at it) almost corner to corner and then the side blinds are installed butted up to the front blind. To measure for the front blind, all you do is measure the full width of the bay from side to side and order this blind as ‘Recess Size’. Measure the sides in the same way (ensure you measure both sides separately, as often they are slightly different) so that you measure into the corner again, but then deduct the bracket allowance noted above from the width. This allows for the blind on the front window. The side blinds should then be ordered as ‘Blind Size’.

Measuring the Width – Option 2

This option does not work for every box-bay window. Be sure to check the size of the window frame in the corners first, going from the corner of the bay to the start of the glass pane on both the front and the sides. If either measure less than 70mm, follow options 1 or 3 instead, so that you do not end up with blinds that do not quite cover the glass area. The idea behind this option is to have all three blinds meet in the corners of the bay but without overlapping. This is done by leaving a square void in the corners. Measuring is straight-forward, you just need to measure all three sections directly into the corners. You will then deduct the bracket allowance from the measurement for each of the side blinds and deduct double the bracket allowance from the measurement for the front blind. All three would then be ordered as ‘Blind Size’.

Measuring the Width – Option 3

This option is less frequently used than the first two options, but it is certainly still a useful method. Some box-bay windows have side windows that are so narrow, that by time you have deducted the bracket allowance from the side measurements, the measurement you end up with is smaller than the minimum width we can make a roller blind. In this option, the side blinds continue into the corners and the front blind sits between them. Measure the sides into the corner and use this measurement to order both as ‘Recess Size’. The front should be measured corner to corner again, but then deduct double the bracket allowance from the width to allow for the side blinds, this should also be ordered as ‘Recess Size’.

Top-Tip:

Always check the widths in three places, as you would for regular recessed windows. It is not unusual for bay windows to not be dimensionally correct, and you may find that the widths vary, even if at first glance the windows look even. It is always the smallest of three measurements that you should be working with.

Measuring the Drop

This will be the same for all three options. You will simply measure from the point where the blind is being mounted down to where you want the fabric to stop. Remember that you don’t need to add any allowances on for the tube and brackets, as we will add enough fabric onto the tube to account for this.

Window Handles

Please ensure you consider projecting window handles when looking at where you will be mounting your blind. Don’t forget you can choose the ‘Reverse Roll’ option which will mean the fabric rolls off the front of the tube (so away from the window) which may help the blind clear any projections.

Preparing to Measure – Angled Bay Windows

To measure angled bay windows, you will need;

2x pieces of A4 or A5 sized paper or card
Pencil
Ruler
Metal Tape Measure – Always use a metal tape measure to ensure your measurement are as accurate as possible.


Measuring the Width

1.Consider whether you will be top fixing or face fixing your roller blinds. The allowance you need to make for the brackets when top fixing is 50mm, when face fixing it is 70mm. Bear in mind you will need a flat surface of 50mm to fit the bracket to. If you have window handles or vents that stick out from the window frame, measure how far these protrude and add this to the bracket depth. This will be used as measurement (A).

2. Using two pieces of paper, place them edge to edge and mark both of them at the required measurement (A).

3. Slide the two pieces of paper towards each other along the window sill of the bay until the two marks that you made meet up.


4. Using a pencil, make a mark on the window sill at the point where the paper meets the window frame.


5. Measure from one mark to the next as detailed in the diagram. This will establish the width of the blind that you will need to order.



Measuring the Drop

Measure the drop from where the top of the blind will sit down to where you want the blind to end (typically the window sill). All of the blinds should then be ordered as ‘Blind Size’.

Duette® TruFit™ Blinds
NON-SQUARE WINDOW BEADING

Measure Method A – Non-square ‘Small Seal’

EXAMPLE; MOUNTED PROFILE ONTO GLASS
SQUARE WINDOW BEADING

Measure Method A – Square ‘Small Seal’

EXAMPLE; MOUNTED PROFILE ONTO GLASS
Duette® BB10 Blinds
MEASURING INSIDE THE WINDOW REVEAL

• Measure the length from the top of the reveal to the sill in several places as your window may not be square, and choose the length that best suits. This is the finished length of your blind.
• Measure the width of the reveal at its narrowest point. Subtract 2cm from the reveal width; allowing for a 1cm clearance to each side. This gives your finished width.
• Choose a mechanism and to which side this will hang.

TOP-TIP:

Ensure that the blind is far enough away from the window handles to prevent obstruction. You may need to fix the blind to the ceiling of the reveal.


MEASURING OUTSIDE THE WINDOW REVEAL

• Decide on your preferred blind position. The top of the blind usually looks best at 10cm above the reveal. For the hem position, blinds usually fall 5-15cm below the sill (or to the sill if the sill projects). Measure the length between the top of the blind and the hem position. This is the finished length (measure in several places to find the length that best suits).
• Measure the reveal width. Now decide how much the blind is to overhang beyond the reveal and add this to your reveal width (usually at least 5cm to each side, check for obstructions). This gives your finished width.
• Choose a mechanism and to which side this will hang.

Duette® SmartCord® Blinds

Measuring for your new blinds will be effortless with our easy-to-follow guide! Keep an eye out for our helpful tips, allow plenty of time, and most importantly, double check everything!

Measuring Standard Windows

The first thing to consider when measuring for your new blinds is where you will be fitting them, inside or outside recess

Soon we will have a couple of handy video guides, which will talk you through the process of measuring standard windows, which differ depending on where you will be fitting your blinds. You can fit either Inside Recess (so the blind will fit inside the window recess, either top fixed or face fixed, and drop down to the bottom of the window) or Outside Recess (so the blind will face fix onto the wall above the recess, oversail the window either side, and drop down as far as you need it to go). If you prefer a written guide over a video guide, or would like to use it in conjunction with the video, scroll down for a step-by-step guide. This will also cover non-standard windows (such as partly tiled recesses and bay windows).

Inside Recess

Measure the full width and height of the recess (some people refer to this as the window reveal) and we will make the appropriate deductions to ensure your new blind fits perfectly.


Measure in 3 places
for both the width and the drop. Use the smallest measurement, this will ensure the blind doesn’t catch the side of the recess as it is lowered

Don’t make any deductions from this measurement – we will deduct 5mm from the width for Duette® SmartCord® blinds. We won’t deduct anything from the drop.

Please use a metal tape measure – cloth ones can stretch and give you inaccurate measurements. Remember to double check all measurements!

 

Top-Tip:

Check that your recess is deep enough to fit the blind into, also bearing in mind any obstructions such as handles.

When fitting Duette® SmartCord® blinds, your recess will need to be at least 50mm deep.

 

Outside Recess

Measure the full width and height of the recess (some people refer to this as the window reveal) and add as much as you need to the top and to each side, we will make the blind at the size you have specified, there will be no deductions to the width or the drop.

 

To minimize light leakage, we recommend that the blind overlaps the window recess by at least 70mm at the top and 50mm either side. This is especially important if the blind will be in a Bedroom or somewhere someone is likely to sleep.

How far you choose to overlap at the bottom is simply personal preference, just make sure you take any obstructions into account, such as radiators.

 


Top-Tip:

If you are replacing an existing blind with one of the same size, simply measure the blind (including its fittings) and specify ‘Blind Size’, we will make you one the same size.

Measuring Other Window Types

From partly tiled recesses to bay windows, we understand that not everyone will have a conventional square or rectangular shaped window. This is why we have delved deeper into the measuring aspect to include some of these less conventional windows, to ensure these windows are just as easy to measure as others.

Part-Tiled Recesses

If you have tiles part-way up your recess (which is most often the case in kitchens and bathrooms) then the space between the tiles is likely to be the narrowest point in the recess.



Measure between the tiles
to ensure your blind will fit. Enter this as a recess size and we will deduct 5mm off the overall width to ensure the blind doesn’t catch the side of the tiles when it is lowered. Please bear in mind the gaps at the side of the blind above the tiles will be wider.

 

 

 

Top-Tip:

Carry out the same method of measuring if you have a picture rail (dado rail), skirting board or other items on the inside of the recess.

Bay Windows (Angled & Square)

Bay Windows can come in a variety of different shapes and sizes – from square bay windows, to 3, 4, 5 (and sometimes even more) angled bay windows. You may also have a half-bay or L-shaped window, which can be particularly prevalent in buildings which have been renovated and had a dividing wall added between 2 rooms. No matter which type, we can help, simply check the links below to guide you through the process!

The main point to note with roller blinds in bay windows is that, due to the spacing caused by the brackets, there will always be gaps in between the fabric of the blinds where the windows are not covered. This becomes more apparent when the fabric is blackout, as it accentuates how much light there is at the sides of the blinds.

Roller blinds remain a popular choice for all types of windows, including bay windows, but it is always worth considering all of the characteristics of different types of blinds, before making your final decision.

Preparing to Measure – Square Bay Windows

We have detailed 3 options below, which highlight the 3 different ways you can fit Duette® SmartCord® blinds in Square Bay/Box Bay Windows. After looking the images and reading the measuring details, decide which option you think will suit your bay window best. Consider whether you will be top fixing or face fixing when making this decision.

The depth of the bracket for Duette® SmartCord® blinds is 50mm, ensure this measurement is added on to any projections, as per note 1 below.

Ensure you always use a metal tape measure to ensure your measurement are as accurate as possible.

Option 1

Option 2

Option 3

Measuring the Width – Option 1

This is the most common method of installation in a box-bay window. The blind runs across the front (or back, depending on which way you are looking at it) almost corner to corner and then the side blinds are installed butted up to the front blind. To measure for the front blind, all you do is measure the full width of the bay from side to side and order this blind as ‘Recess Size’. Measure the sides in the same way (ensure you measure both sides separately, as often they are slightly different) so that you measure into the corner again, but then deduct the bracket allowance noted above from the width. This allows for the blind on the front window. The side blinds should then be ordered as ‘Blind Size’.

Measuring the Width – Option 2

This option does not work for every box-bay window. Be sure to check the size of the window frame in the corners first, going from the corner of the bay to the start of the glass pane on both the front and the sides. If either measure less than 70mm, follow options 1 or 3 instead, so that you do not end up with blinds that do not quite cover the glass area. The idea behind this option is to have all three blinds meet in the corners of the bay but without overlapping. This is done by leaving a square void in the corners. Measuring is straight-forward, you just need to measure all three sections directly into the corners. You will then deduct the bracket allowance from the measurement for each of the side blinds and deduct double the bracket allowance from the measurement for the front blind. All three would then be ordered as ‘Blind Size’.

Measuring the Width – Option 3

This option is less frequently used than the first two options, but it is certainly still a useful method. Some box-bay windows have side windows that are so narrow, that by time you have deducted the bracket allowance from the side measurements, the measurement you end up with is smaller than the minimum width we can make a roller blind. In this option, the side blinds continue into the corners and the front blind sits between them. Measure the sides into the corner and use this measurement to order both as ‘Recess Size’. The front should be measured corner to corner again, but then deduct double the bracket allowance from the width to allow for the side blinds, this should also be ordered as ‘Recess Size’.

Top-Tip:

Always check the widths in three places, as you would for regular recessed windows. It is not unusual for bay windows to not be dimensionally correct, and you may find that the widths vary, even if at first glance the windows look even. It is always the smallest of three measurements that you should be working with.

Measuring the Drop

This will be the same for all three options. You will simply measure from the point where the blind is being mounted down to where you want the fabric to stop. Remember that you don’t need to add any allowances on for the tube and brackets, as we will add enough fabric onto the tube to account for this.

Window Handles

Please ensure you consider projecting window handles when looking at where you will be mounting your blind.

Preparing to Measure – Angled Bay Windows

To measure angled bay windows, you will need;

2x pieces of A4 or A5 sized paper or card
Pencil
Ruler
Metal Tape Measure – Always use a metal tape measure to ensure your measurement are as accurate as possible.


Measuring the Width

1. The depth of the bracket for Duette® SmartCord® blinds is 50mm. Bear in mind you will need a flat surface of 50mm to fit the bracket to. If you have window handles or vents that stick out from the window frame, measure how far these protrude and add this to the bracket depth. This will be used as measurement (A).

2. Using two pieces of paper, place them edge to edge and mark both of them at the required measurement (A).

3. Slide the two pieces of paper towards each other along the window sill of the bay until the two marks that you made meet up.


4. Using a pencil, make a mark on the window sill at the point where the paper meets the window frame.


5. Measure from one mark to the next as detailed in the diagram. This will establish the width of the blind that you will need to order.


Measuring the Drop

Measure the drop from where the top of the blind will sit down to where you want the blind to end (typically the window sill). All of the blinds should then be ordered as ‘Blind Size’.

Window Treatment Cornwall

Get in touch






    Get in touch if you need any more help or information

    At Westcountry Blinds, we design and manufacture bespoke blinds, shutters and curtains for clients across the county. This includes Hayle, Penzance, Helston, Truro, St Ives, Falmouth and Newquay.

    If you want to pop over to see us, we have examples of most of our products on display in our Hayle showroom.

    We are here 09:00-17:00 Monday to Friday and 09:00-13:00 on a Saturday. We are closed on Sundays and Bank Holidays.

    If you’re unable to pop in, please give us a call to discuss your project and what you need. Or fill out our contact form, and we’ll get in touch to discuss your needs further.

    Call us

    01736 752397

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