For a perfect fit, you need to discover the reference on the nameplate at the top of the window. You will need to record this information for the order process.

Though the illustration above shows a VELUX window plate, most of the roof window manufacturers will have the same on their window, showing the window type and size..

The exception is Keylite, who have a plate but who choose to show a production number, the intention being that you then phone or mail to get the window size. We have therefore included a chart on our site where you can check the glass size and order the comparable RoofLITE size for a perfect fit.

To view the chart please click here