Can a broken Velux window be repaired?

A cracked pane is a safety problem before it is a repair problem. If glass has broken, keep people away from the area beneath it, cover the opening from inside if you can do so without reaching over it, and do not try to patch it from the roof. If water is coming in, put a bowl under it and photograph the damage. Keeping rain out takes priority over any lasting mend, and a bedroom drip is easier to manage if the bed is moved or covered with a sheet meanwhile.

Then identify the window. Roof windows carry a label, usually on the edge of the sash or inside the frame, giving the maker, model and size. Parts such as seals, glazing units and hardware are ordered against that information, so a photograph of the label saves time before anyone visits. An old window of a discontinued pattern may have no parts left on sale, which pushes the verdict toward replacement however sound the frame looks.

Worn gaskets and weather seals can be renewed, and so can handles, hinges and opening mechanisms where the maker still supplies them. A single cracked or misted glazing unit can be exchanged for a new one in the same frame, which is often cheaper than a new window. Blinds, trims and the lining around the window can be mended separately, without touching the roof. Opening hardware that sticks or will not hold the sash up is often a worn part rather than a ruined window, and it is worth asking about before you accept a quote for a replacement.

Leaks are the most common reason for a call, and many are not caused by the window at all. A slipped flashing, cracked tiles beside the frame or a blocked gutter above can each let water in beside a window that is perfectly sound. Our guide to leaking roof windows goes through the checks, and the answer on flashing kits describes the part repaired most often. Keep any paperwork that came with the window, such as the label and the date it was fitted, since it helps whoever assesses it next.

Timber frames rot when they stay wet, and a rotten frame cannot be mended to the standard needed to keep a roof dry. A frame that has warped so the sash no longer closes square will not seal however fresh the gasket is. A window whose parts are no longer made, or one that has already been repaired several times, is rarely worth another visit. Ask what a replacement would change as well as what it would fix: a new window should close tightly, open smoothly and show a warmer inner pane, otherwise the money is not well spent.

Misting between the panes is a repair only if the right glazing unit can be bought for that frame. If it cannot, the whole window goes. Where the old window is single-glazed or poorly insulated, replacing it also solves a thermal problem that a repair leaves alone. Our guide to replacing an old Velux window goes through swaps and upgrades, and our condensation answer shows how a failed unit differs from damp room air.

A repair leaves the window as it is, so it brings no new energy requirement. A replacement does. Approved Document L 2021 (Table 4.2) wants a fitted roof window to reach a U-value of 1.4 or Window Energy Rating Band B whenever the old one is renewed in a home that already exists. Table 3.2 of the 2026 edition keeps that standard once it applies from 24 March 2027.

Swapping a window for another of the same kind in the same opening is not normally a planning matter, yet listed buildings and some Article 4 areas are exceptions, so speak to the council first when the property is listed or lies within a conservation area. A registered building control approver, or the council's team, can say if notification is due, and our guide to skylights and roof windows explains the wider rules in plain words.

We look at the window from inside and out, photograph the frame, the glazing, the flashing and the roof around it, and give you an outright verdict: mend, make do for a while, or renew. If a new gasket and a re-dressed flashing will hold, we put that forward. A whole new window is not pushed when mending will do the job, and the photographs are yours to keep.

The cost depends on what the visit finds, how the roof is reached and whether parts must be ordered, so no figure is sensible before the window has been seen. For typical national figures on fitting a new unit, see our guide to roof window installation costs. When we have finished looking, a written quote follows, and its price is a single sum.