The first rule of thumb is to make sure you take accurate measurements  in millimeters not inches. This gives you a finer level of accuracy and  means there’s no room for error if we have to convert the measurement to  metric.

So firstly step outside. You need to take height and width measurements  for the brickwork opening. Bear in mind that the height measurements  must be from underneath any existing removable windowsill. If your  property is rendered, simply take off a little of the render and measure  to the brickwork edge.

Remember the opening may not be exactly square so take a minimum of  three measurements – top, middle and bottom, for the height and the same  again for the width. This means your window manufacturer can get an  accurate view of the exact size of the space the finished product will  be fitted into. The final width and height measurement the manufacturer  will use is the smallest one.

This sounds like odd advice but you need to take off 10mm from the final  height and width measurements. This is to allow for a small fitting  allowance around the new frame and means the fitter can make sure the  new window frame sits squarely when it’s in place. Any gaps are then  fitted with spacers and filled to keep the frame in just the right  position.

This is a common error and certainly one to avoid. Ignore the old window  frame – this is going because it is no longer suitable. Consider the  fact that it may well have warped so the last thing you want to do is  take measurements from it!

Make sure you check (and double-check) your measurements so you are 100%  sure you have them correctly. This is important because we will not  accept responsibility for incorrect measurements and you will still have  to pay for a window that doesn’t fit. If you are unsure, consult a  professional installer or builder and give yourself total peace of mind.

Taking all the above information in to account, when inputting your  measurements we require you to provide us your overall brick-to-brick  measurement minus the 10mm fitting tolerance. We will automatically  include the cill in to the measurements you provide us – pending you  require one that is!

f you struggle, or you would like us to contact you for piece of mind, just leave a note asking for a  call back!

This is a common error and certainly one to avoid. Ignore the old window  frame – this is going because it is no longer suitable. Consider the  fact that it may well have warped so the last thing you want to do is  take measurements from it!

This is a common error and certainly one to avoid. Ignore the old window  frame – this is going because it is no longer suitable. Consider the  fact that it may well have warped so the last thing you want to do is  take measurements from it!

This is a common error and certainly one to avoid. Ignore the old window  frame – this is going because it is no longer suitable. Consider the  fact that it may well have warped so the last thing you want to do is  take measurements from it!