The short answer
Yes. A blind can be added to an existing Velux roof window, usually without touching the roof. The blind is made to fit one window size and type, so you need the product code from the label on the window frame. Match the blind to that code, choose the style that suits the room, and fit it to the sash from inside.
Adding a blind later is a simple job for most roof windows, if the blind is made for your window. The code on the frame is the place to start.
Finding the code on your window
Roof window blinds are not universal. Each one is cut and mounted for a particular size and model of window, so a blind that fits next door's window may sit loose on yours. The match is made by a product code, a string of letters and numbers that identifies the window.
Where do I find the Velux code?
Open the sash and look at the frame. A white label is usually fixed to the inner edge, at the top or the side, and it carries the code along with a date and other details. If the label has worn or been painted over, measure the outside of the frame and give us the measurements with a photograph of the window, and we can work out the likely size from those.
Do this before you shop, because a blind bought on looks alone tends to go back. If the window is old, the code on the label may belong to a model that is no longer made, which can limit what is on offer. In that case ask the supplier whether a compatible blind still exists. Our answer on Velux window sizes explains how the codes relate to the size of the opening, and the main roof windows page covers the wider work.
Choosing the right type of blind
There are three broad choices for the inside of a roof window. A pleated blind folds into a narrow stack and filters light softly. A roller blind is a plain sheet that rolls up into a tube. A blackout blind blocks out most daylight, which suits bedrooms, particularly in a loft room that catches the early sun.
Will a blind keep the room cooler?
An inside blind softens glare and stops the room glowing, but the sun has already passed through the glass by the time it hits the blind, so some of the heat stays in the room. Blinds fitted outside the glass stop more of that heat before it enters. If overheating is the problem, ask about an external option for your window code.
A blind also changes how the window behaves on cold nights. With the blind down, a layer of cool air can sit between the blind and the glass. That matters if you already see droplets on the pane, and our page on Velux condensation covers it. An inside blind will not cure damp air, so ventilation still counts.
Fitting the blind to the sash
Most inside blinds are fitted from the room, without going on the roof. The frame holds clips or channels, the blind slides or clips in, and the side tracks guide the pull. The sash, the opening part of the window, must still swing freely, so check the clearance by holding the blind against it first. A snagging blind can wear the seal over time.
Can I fit it myself?
Many people do. If the window sits above a staircase, a high landing or an awkward angle, working at that height is where jobs go wrong, and a ladder resting on the stairs is not a safe place. We are happy to fit blinds as part of a visit, particularly when we are already on site for other roof window work.
Look at what is above the frame too. If a leak stain is spreading on the lining, a new blind only hides the problem. Water entering at the corners of a roof window usually points to the flashing, the metal that seals the frame to the roof covering. Tell us what has marked the lining, and we check the outside before the blind goes up.
When a new blind is the wrong answer
A blind improves comfort and privacy, but it does not repair a tired window. If the sash is hard to open, the seals have perished or the double-glazed unit has misted between the panes, a blind will not help for long. Money is better spent on the window itself.
Is it worth replacing the window first?
If the window is old, it may be time. A replacement window brings a new product code and a new range of blinds, and a new window is a reasonable moment to choose the blind at the same time, so you can order both together. Our page on replacing a Velux in the same opening explains the process. Where only the glass has failed, the answer is different, and we explain it when we survey.
If the window is sound, a matched blind is a short job next to a new window. Send us a photo of the label and the room, tell us whether the glass is clear, and we will say whether a blind is enough.
More on blinds for roof windows
Who supplies the blind if you fit it on a roof visit?
The blind is a made-to-fit product, so it comes from the supplier for your window code, and the terms are the maker's. If we fit it during a visit, the fitting sits in the written price for that visit. Keep the receipt and the product code with your records for the window.
Can I put an ordinary curtain pole or blind on a roof window?
You can, but a loose blind hangs awkwardly on a sloping sash and may press on the opening mechanism. Blinds made for the window run in side channels so they stay flat. If you want a different look, ask the supplier which fabrics and colours are made for your code.
The full picture: Velux roof window and skylight installation in Taunton ยท More short answers