How to Find the Exact Code on Your VELUX Roof Window

Roof window blinds are not cut to a tape-measure size. Each one is built for a specific window model, so the blind's frame, side channels and fabric width line up with the brackets already on your window. That is why the single most important thing you can give us is the code printed on your window. Get the code right and the blind fits. Get it wrong and no amount of careful fitting will fix it.

Where the plate is

On a VELUX window the identification plate sits on the sash, the part of the window that opens. Open the window fully (or swing it round, if it is a centre-pivot model) and look along the top of the sash frame, just under the top cover. On most windows you will see a small metal or foil plate. On some older or painted windows it may be partly hidden by paint, dust or a previous blind's top bracket, so a torch and a soft cloth are useful.

If you are working on a high window, use a stable step or platform rather than leaning out from a bed or banister. You only need to read a few characters, so a photo taken on your phone and zoomed in afterwards works well.

How to read the code

The plate carries several pieces of information. For ordering a blind you need two of them:

• Window type — a group of letters, such as GGL, GGU, GPL or GHU. This tells us which family of window you have and how it opens.
• Size code — usually a letter followed by two digits, such as C04, M06 or S08. This identifies the exact frame size within that family.

The plate may also show a longer serial or production number. You do not need it for a blind, and it should not be mistaken for the size code. If you are unsure which part is which, send us a photo of the whole plate.

Our window code guide has an animated example and real plate photos from several brands if you want to compare what you see.

Why we do not guess sizes from old codes

Older VELUX windows can carry codes in a different format, and you will find conversion charts online that claim to translate them. We do not use those charts to choose a blind for you. Over the years window families have changed, and a chart that is right for one model can be wrong for another that looks similar. A blind built from a guessed size is a made-to-order item that may not fit, and that is a poor outcome for everyone.

If your plate shows an older-style code, or you cannot match it to the types and sizes listed in the shop, contact us with a clear photo. We will confirm the right option with you before anything is made, or tell you honestly if we cannot supply a blind for that window.

If the plate is missing or unreadable

Plates do get painted over or removed during renovations. Before giving up, check the following:

• Look along the full length of the top sash bar, not only the centre.
• Check the side of the sash on the hinge side; some windows have a second label there.
• Look for paperwork from the original installation or the house build; window specifications are sometimes listed.
• Check whether an existing blind has its own label on the top bar. It may list the window size it was made for, but treat this only as a clue to confirm, not as proof.

If none of that works, our team can talk you through what else to look at. Our contact page lets you upload photos of the window, which is often the quickest way to sort it out.

Compatible blinds, explained honestly

VELUX® is a registered trademark of VKR Holding A/S. The blinds we sell are not made by VELUX; they are made-to-measure blinds built to fit VELUX roof windows using the window type and size code. They clip into the same mounting points that the window provides for a blind. Original VELUX blinds are a different product sold through other channels, and we do not claim our blinds are identical to them.

Checklist before you order

• Window type copied exactly, letters in the right order.
• Size code copied exactly — watch for 0 (zero) versus O, and 1 versus I.
• One code per window. Two windows side by side are not always the same size.
• Photo of each plate kept on your phone in case you need to check later.

When you choose a window type and size in the shop, only fabrics and options built for that window are shown, so you are not left matching measurements by hand.