How long do VELUX windows last?

Thinking of a roof window as one object is what makes lifespan questions hard. It is a frame, a sash, a sealed glass unit, gaskets, a hinge or pivot mechanism, a flashing kit and a finish, and each ages differently.

The frame and sash

Pine frames are painted or lacquered white, and polyurethane frames are a coated core. Both are built for a roof, where they face rain, sun and frost. They tend to outlast the glass in them, provided the finish is intact and the window has not been abused.

The sealed glass unit

Two or three panes with a gas-filled gap and a spacer. When the edge seal weakens, moisture gets into the gap and the unit mists. This is the most common reason a window looks past its best, and the glass alone can often be replaced in the existing frame.

Gaskets and seals

Rubber and foam seals soften and compress over time. They are cheap parts, and they are what makes the window close tightly.

The flashing

A metal or composite kit that bridges the frame and the roof covering. It is made to be durable but sits in the most exposed position on the window.

The mechanism

Hinges, pivots and handles that move every time you open the window.

Four things do more damage than age.

Weather exposure

A south-west slope near the coast takes salt, wind-driven rain and strong sun together. The same window on a sheltered north slope inland ages more slowly. Around Exeter, the Exe estuary and the East Devon coast are harder on finishes than the Culm valley.

Condensation

A bathroom, kitchen or bedroom with poor ventilation puts moisture on the frame and lining. Over years, that affects the finish and can mark the plaster. Opening the window for purge ventilation and running the extractor helps, and ventilation is covered by Part F where it applies.

Poor fitting

A window fitted with the wrong flashing for the roof covering, or without proper sealing at the head and sill, ages early however good the product. This is the biggest variable and the only one in your hands when you choose who installs it.

Neglected finish

Painted pine needs the white finish kept intact. Where it chips and bare wood meets moisture, the frame starts to suffer. A polyurethane frame is less sensitive to this.

You are looking for patterns, not single events. A single misted pane is a glass-unit question. Several of these together point to the window as a whole:

• the sash no longer closes square, or the handle needs force;
• misting between the panes on more than one unit;
• soft or flaking finish on the frame, especially at the bottom corners;
• staining on the lining or plaster beside the frame;
• draughts around the sash when closed.

Any of these is worth asking about at a survey, because the answer is not always replacement. Glass-only replacement is not notifiable to Building Control, and a new sash or seal can restore a window that is otherwise sound.

This is the practical decision once a window starts to show its age. If the frame and sash are sound and only the sealed unit has failed, replacing the glass leaves the opening, the flashing and the lining untouched. If the frame is soft, the sash is out of square or the flashing is tired, the whole window is the better answer, and a whole-window swap is notifiable building work that must meet Part L. We handle the Building Control notification.

A whole-window swap also gives you a modern glazing unit and a fresh flashing kit, which resets the clock on all the parts that matter. See can a VELUX window be replaced like for like for how a swap works, and VELUX flashing kits explained for why the flashing is replaced with the window.

Most of what extends a window's life is simple. Clear leaves and moss from the flashing and the roof near it, wipe condensation off the frame, and keep the white finish sound with a touch of paint where it chips. Open the window regularly so the mechanism stays free. If the room is damp, deal with the ventilation as well as the window.

Choose the glazing to suit the room too. Our guide to VELUX glazing options compares the panes, and a polyurethane frame is the usual choice for a bathroom or kitchen, where moisture is constant.

Age matters differently depending on the house. In a Victorian villa or a 1930s semi, a roof window may have been put in during a loft conversion decades ago, and the surrounding plaster and lining may be older than the window. A cob cottage or a granite house on the moor edge has a deep, irregular roof build, and the flashing there is working harder to meet an uneven covering. In each case, when a window comes out, the survey is a chance to look at the ceiling and lining as well, and to decide whether the finish around the new window should be tidied at the same time.

It is easier to do that once, with the old window out, than to come back to it later.

VELUX windows carry the manufacturer's own warranty, and the terms and periods are set by the manufacturer, so read them for your model and date of purchase. Our own 10-year workmanship guarantee is separate. It covers the installation work we do: the weathering and flashing we fitted, the fixing of the unit, and the lining and finish we formed. It does not cover manufacturer defects, which fall under the manufacturer's warranty, although we help you make a claim. See our guarantee for the full terms.

If your windows are old enough to be asking the question, it is worth deciding what you want from the next ones: a different type, a larger size, a blind, a better glazing option. The VELUX window installation page covers the choices, and asking for a quote starts with a survey where we look at the windows you have and tell you which part, if any, needs replacing.