How Long Do Wooden Windows Last? The Truth Behind Timber Longevity

A well-manufactured wooden window, made from the right material and looked after properly, will last 50 years or more. The Accoya we use carries a 50-year warranty from its manufacturer against rot and decay.

How long any particular window lasts comes down to three things: what it is manufactured from, how it is built, and how it is looked after. The gap between a window that lasts decades and one that falls apart in 15 years sits in those three answers.

Why Older Wooden Windows Got a Bad Reputation

Plenty of homeowners still judge wooden windows on the softwood frames fitted in the 1970s and 1980s. Those rotted, swelled, stuck in their openings and let draughts through.

We still see windows barely a decade old with frames swollen so badly the sashes will not open. Cheap softwood with a site-applied finish will do that over time.

Windows from that era were manufactured from untreated or poorly treated softwood, with basic single glazing and limited weather protection, so the reputation they left behind is understandable. The materials, manufacturing methods and coatings in use today have moved a long way from what was going into buildings forty years ago.

What Determines How Long a Timber Window Lasts

The Timber Itself

The species and treatment of the wood are the biggest single factor in how long a window lasts. They decide how well it resists moisture, rot, insect attack and movement.

We use Accoya timber as standard for our windows and doors. Accoya is modified wood, put through an acetylation process that changes it at a cellular level so it resists rot, swelling and shrinkage.

Accoya has 75% less swelling and shrinkage than conventional timber, which is why the joints stay tight, the coatings last longer and the window holds its shape for decades. It is FSC and PEFC certified, sustainably sourced and carbon negative over its lifecycle, and it is made for external joinery in a British climate.

Windows manufactured from standard softwood, even treated softwood, will not perform to the same level, so the specification of the wood is where longevity starts.

Manufacturing Quality

How a window is put together decides how long it holds together. Joints that are machined precisely, glued properly and reinforced where they need to be will hold far longer than roughly cut ones.

We manufacture all our windows at our factory in West Yorkshire using traditional joinery techniques, and every window is made to measure. The joints are engineered for the size and configuration of that particular window rather than cut from a standard template.

Working in a factory also keeps the quality consistent, because every window goes through the same process, the same checks and the same finishing.

Coatings and Finishes

The coating system is what protects the wood from moisture and UV. A good factory-applied finish will last far longer than a coat of paint brushed on at the property.

We finish our windows with Sikkens coatings, which are formulated for exterior joinery. Applying them in the factory means the coating goes onto prepared, dry wood in controlled conditions, which gives better adhesion, a more consistent finish and a longer life than site-applied paint.

With Accoya underneath, the coating system lasts longer still. The wood is more dimensionally stable, so there is less movement, less stress on the paint film, fewer cracks and better protection over the long term.

Maintenance

Wooden windows need looking after, as any external building material does, though the upkeep on a modern one is lighter than its reputation suggests.

With our factory-applied finish we recommend an inspection every few years and a light maintenance coat after around eight years on average. On the most exposed elevations, that comes round at least every five years, which matches what we tell customers in extreme weather locations.

The useful part is that looking after a wooden window adds years to its life, because the wood can be sanded, filled and recoated back to full condition. A uPVC window that has discoloured, warped or cracked can only be replaced.

Installation and Exposure

Where and how a window is installed matters as well. Good detailing, proper drainage, the right sills and correct sealing all add years to a frame that would otherwise sit in standing water.

A fully exposed, west-facing farmhouse elevation with no overhang takes the worst of the weather, and with Accoya underneath and a properly applied finish on top those windows hold up.

Exposure tends to affect how soon the finish needs refreshing rather than how long the window lasts structurally.

How Does Timber Compare to uPVC?

A standard uPVC window has a lifespan of 20 to 25 years, after which the plastic discolours, the seals degrade and the mechanisms wear out. Once a uPVC frame fails the whole unit has to be replaced.

A window manufactured from Accoya, with a proper coating system and reasonable maintenance, will last 50 years or more. When it does eventually need attention, the wood can be sanded back and recoated in place.

Across the lifetime of a building that makes wooden windows the more cost-effective choice, because the windows do not need replacing as often. They also hold or add value to a property, particularly on period and character homes.

What Does the 50-Year Warranty Actually Cover?

The 50-year warranty comes from Accsys, the company that makes Accoya. It covers the timber itself against rot and fungal decay, and against excessive swelling or shrinkage, for 50 years above ground. Where the timber sits within 20cm of the ground the period is 25 years.

The windows still need periodic care, as all external joinery does. The warranty covers the timber, not the paint finish, the glass or the hardware.

Is Timber the Right Choice for Your Property?

It is worth the money if you want windows that last decades and suit the character of your property. They can be maintained and kept in condition rather than replaced.

We manufacture bespoke wooden windows at our factory in Clayton, West Yorkshire: sliding sash windows, flush casement windows and stormproof windows. Every one is made to measure, double glazed and made from Accoya with its 50-year timber warranty. We supply nationwide and install across West Yorkshire.

To talk through your project or ask for a quote, call us on 01274 911 316 or use our contact form.