Measuring a Standard Rooflight could not be made any simpler, here we have designed and manufactured our Rooflight’s for the easiest of installations.

Just follow our easy measure steps below!  If you have any questions, please don’t hesitate to get in contact with the team.

Step 1

  • If you are yet to build your curb and you wanted to make a saving when ordering your Rooflight, your best option is to make a curb to fit our Standard Size Rooflight’s.
  • If you order a Rooflight size: 1000 x 1000 mm you would want to make the curb (external sizes) 972 x 972 mm – see step 3 for the clearances needed

Step 2

  • Once your curb is constructed, please ensure that it meets all requirements - The curb should raise the Rooflight at least 4 inches (100mm) above the roofing material. Usually 2 by 2 timber works well
  • Check the curb for Square by measuring diagonally from corner to corner; the distances should be identical. You can also use a framing square.

Step 3

  • Once your curb is constructed, you will need to take your overall kerb dimensions including your weather finishes  (width x depth) –
  • you will then need to make allowances for the frame to fit over the curb upstand – *we advise to make these quite big in case of anything being out of square*
  • Add on 6mm of metal each side.
  • Allow around 8mm of clearance all the way round
  • This should give you 28mm bigger of the curb size on each the width and the depth
  • If your curb external sizes are 1000 x 1000 mm – you should order a Rooflight being 1028 x 1028mm – this is the minimum you should allow – you can make this bigger to ensure your Rooflight fits

Step 4

  • Once you have got these dimensions you should inform us (at any time – can be after you order)

Step 5

  • Double check these sizes as Rooflight’s are non-refundable and you do not want to have any mistakes!
  • Use our simple website to order your website, if you have any questions or you wanted to double check everything before you order, please do get in contact with the team, we are more than grateful to help.


  • If you require a bespoke Rooflight that the sizes are not on our website, please contact us for to place an order.

Congratulations! – You have now measured your Rooflight for ordering on our website!