If your Velux window is leaking, stuck, dripping with condensation, or the remote has stopped talking to it, the first question most homeowners ask is whether it can be fixed at all, or whether they’re now looking at a full replacement. In the vast majority of cases it can be fixed, and usually for a lot less than people expect. This guide covers every fault we’re regularly called out to across the North East, what causes each one, roughly what it costs to put right, and the point at which repair genuinely stops making sense.
Leaking Velux Windows
Water coming in around a roof window is the fault that panics people the most, and understandably so. But a leak rarely means the window itself has failed. In our experience, nine times out of ten the water is coming in around the window rather than through it.
The usual suspect is the flashing kit, the metal collar fitted between the window frame and the surrounding roof covering. Flashing has a working life, and on a window fitted more than 15 years ago it’s often corroded, cracked, or simply comes away from the tiles slightly. Wind-driven rain during a storm will find that gap even if the window has been bone dry for years beforehand, which is why so many leak calls come in straight after a bad night of weather.
The other common cause is a blocked drainage gutter along the top edge of the flashing. Moss, roof grit, and leaf debris collect there over time, and once it’s blocked, water backs up and finds its way under the tiles instead of running off. This one is often mistaken for a “window fault” when it’s really just five minutes with a soft brush and a hose.
Less often, the leak is coming from the window itself: a perished seal around the glazing unit, or in older timber-framed models, a coating that’s worn through and let moisture into the wood. If the frame around the glass feels soft or the paint is bubbling, mention it to whoever comes out to look at it.
Typical repair cost: flashing replacement generally runs from around £150 to £350 depending on roof access and covering type. A blocked gutter clean-out is often folded into a standard callout charge.
One thing worth knowing before you get a quote: flashing isn’t one-size-fits-all. It’s matched to the roof covering around it, so a kit designed for plain tiles won’t sit right on interlocking tiles, slate, or a thatched surround, and fitting the wrong type is a common reason a “repaired” leak comes straight back after the next storm. If your roof covering has changed since the window was originally fitted, perhaps during a re-roof a few years back, that’s worth flagging when you book, since it changes which flashing kit is needed.
What Actually Happens During a Repair Visit
Most people booking their first roof window repair aren’t sure what to expect on the day, so it’s worth setting that out plainly. A proper visit starts with a look at the fault from inside the room and, where it’s safe to do so, from the roof itself, rather than quoting blind over the phone based on a description alone. Plenty of leaks that sound identical on a phone call turn out to have completely different causes once someone’s actually up there with a torch.
For anything involving the flashing or glazing, expect roof ladders or a small scaffold tower rather than someone balancing on the tiles, particularly on a steeper pitch. Weather matters too: flashing and reglazing work generally can’t be done safely in rain or high wind, so if you’re booking during a stormy spell, be prepared for a short delay once someone’s out to assess it.
Condensation on or Inside a Velux Window
Two completely different problems are both called “condensation,” and telling them apart matters.
Surface condensation, the misting you see on the inside of the glass first thing in the morning, is a ventilation and humidity issue, not a window fault. It’s especially common in loft bedrooms and bathrooms where warm, moist air rises and meets cold glass. Cracking a trickle vent, running an extractor fan, or simply airing the room for ten minutes a day usually clears it.
Condensation between the panes is a different matter entirely. If you see permanent misting or a milky patch trapped inside the double glazed unit itself, that’s the seal around the sealed unit failing, letting moist air in where it can’t escape. No amount of ventilation will fix this because the moisture is on the wrong side of the glass. This one genuinely needs the glazing unit replaced.
A quick way to tell them apart: wipe the inside of the glass. If it clears and comes back the next cold morning, it’s ventilation. If the misting is between the two panes and never actually touches your cloth, it’s a seal failure.
Typical repair cost: reglazing a standard-size unit typically falls between £250 and £450, though larger or specialist glazing (laminated, acoustic, solar control) costs more.
Broken or Cracked Glazing
Roof windows take a battering that a normal wall window never sees: hailstones, branches, the occasional bird strike, and roofers’ tools during unrelated work nearby. Velux glazing is toughened and, on most current models, laminated as standard, which is why full breakages are rarer than you’d think. What we see far more often is a cracked outer pane that hasn’t shattered but needs sorting before moisture gets into the seal and turns a simple crack into the condensation problem above.
If only the outer pane of a double or triple glazed unit is damaged, the whole sealed unit still generally needs replacing rather than just the one pane, since they’re bonded together as a single unit. This is one area where trying to save money with a generic glazier rather than someone who works with Velux stock regularly can backfire, since getting the wrong spacer bar width or gas fill wrecks the window’s insulation performance even if the glass itself looks fine.
Typical repair cost: similar to a condensation-related reglaze, roughly £250 to £500 depending on the glazing specification of the original window.
Hinges, Handles and Sashes That Won’t Sit Right
A window that’s become stiff to open, or a sash that no longer sits flush when closed, is usually a hinge problem rather than anything structural. Hinges on a window that gets opened daily for ten or fifteen years wear unevenly, and once they do, the sash starts to sag slightly on one side. You’ll often notice it as a scraping sound before you notice anything else.
Swollen timber frames after a wet spell can cause similar symptoms on older wooden models, and it’s worth ruling that out before assuming it’s the hinge, since a genuinely swollen frame will usually ease off again once the weather dries out.
Locking bars and handles fail more simply: repeated use wears the mechanism, and eventually the handle turns without the bar actually engaging. This is one of the cheapest and quickest fixes on this whole list.
Typical repair cost: handle or locking bar replacement usually sits around £80 to £150. A full hinge replacement, which involves more disassembly, tends to run £150 to £250.
Motor and Remote Faults on Electric or Solar Windows
Electric and solar-powered Velux windows add a motor, a rain sensor, and in the solar version a small panel and battery pack, and any of those can be the actual fault even though the symptom looks the same from the sofa: the window just won’t respond to the remote.
Before assuming the motor has failed, it’s worth checking the basics. On solar models, a battery that’s been sitting in a shaded or north-facing roof through a grey winter can simply run flat, particularly on older units where the battery itself is nearing the end of its life (typically 8 to 10 years). A factory reset on the remote sorts out a surprising number of “dead” windows that are actually just out of sync after a power cut or a battery change.
If the window genuinely won’t move even on manual override, the motor itself has likely failed, and that’s a straightforward like-for-like swap rather than anything more drastic. Rain sensors occasionally stick after prolonged exposure to grime and stop the window from closing automatically, which is worth cleaning before booking a repair.
Typical repair cost: motor replacement is generally £200 to £350. A solar battery pack replacement is usually £80 to £150.
Electric and solar windows are worth telling apart when you’re booking a repair, since the fix is different for each. Electric models are wired into the mains and the fault is almost always the motor or the wiring connection. Solar models run entirely off the small panel and battery built into the frame, so a fault that looks electrical can just as easily be a battery reaching the end of its life, which is a far cheaper fix than a motor swap. Mentioning which type you’ve got when you call saves a diagnostic visit in some cases.
What Affects the Cost of Any Velux Repair
The figures above are a fair starting point, but three things move the price more than anything else: access, roof height, and how old the window is. A ground-floor extension roof is a different job to a third-storey window on a Victorian terrace, and that difference shows up in the quote before any parts are even considered. Height and pitch dictate whether the job needs a roof ladder, a tower scaffold, or in rare cases a full scaffold, and that’s usually the single biggest swing factor between two otherwise identical repairs.
Age matters for a different reason: parts for a window fitted in the last ten years are usually in stock and fitted same-visit, while a genuinely old model (anything before the early 2000s) sometimes needs a part ordered in specifically, which adds a few days rather than any extra labour cost. If your property is listed or sits in a conservation area, that’s worth mentioning too, since any flashing or glazing work visible from the street may need to match specific conservation-style detailing.
When to Repair and When to Replace
Most Velux faults are fixable, and Velux itself designed the product line around that: parts are still available for models decades old, which is unusual in the window industry generally. As a rough guide, repair almost always makes sense if:
- The window is under 10 years old
- Only one component has failed (a seal, a motor, a hinge)
- The frame itself is sound with no rot or serious warping
Replacement starts to make more financial sense when:
- The window is original to a house built before the early 2000s and multiple issues are turning up at once
- The frame has rotted or is structurally compromised
- You’re already planning to upgrade to electric or solar operation, in which case doing it alongside a repair often costs less than doing the two jobs separately
A useful rule of thumb from years of quoting both jobs: if a repair is going to cost more than 40 to 50% of a straight replacement, it’s worth at least getting a replacement quote alongside it before committing.
Frequently Asked Questions
How much does a Velux window repair usually cost?
Most single-fault repairs, such as a hinge, handle, or motor replacement, fall between £80 and £350. Reglazing work runs a little higher, typically £250 to £500, depending on the glazing specification.
Can I repair a Velux window myself?
Cleaning a blocked gutter or checking a remote’s battery is safe enough for most homeowners. Anything involving the flashing, glazing, or electrics is worth leaving to someone trained on Velux products specifically, partly for safety on a roof and partly because DIY work on the flashing can affect the product guarantee.
Is my Velux window still covered under guarantee?
Velux windows carry a 10 year product guarantee, with a shorter 3 year guarantee on electrics, blinds, and shutters. Worth checking the installation date before you pay for a repair that might already be covered.
How quickly can a repair be booked?
Most straightforward repairs can be assessed and quoted within a week, and many are completed on the same visit once the fault’s confirmed and the part is in stock.
If you’re dealing with any of the faults above, get in touch with our team for a straightforward quote, no pressure and no call-out charge just to have a look. You can see what past customers have said about our work on our reviews page, or contact us directly to book someone out.