How Long Do Windows Last in the UK?
- UPVC windows:
You can expect a lifespan of 20–30 years, with some lasting up to 35 years when expertly fitted and properly cared for. - Aluminium windows:
Often lasting 30–45 years, they’re also resistant to warping, swelling, or cracking, even in harsh temperature swings. - Timber windows:
Typically endure for 30–40 years, and with regular, attentive maintenance, they can go well beyond this, sometimes reaching 60 years.
Understanding the typical lifespan of your windows is valuable, as it affects energy performance, heating costs, and potential problems like dampness or mould. Once a window begins allowing in draughts or starts drawing moisture, it can increase the cost of keeping your home warm and may encourage condensation to form. Windows that no longer perform properly can also have a negative effect on your home’s value.
UPVC, aluminium, and timber windows all age differently, as different types of windows for homes often do. Being aware of how each type usually deteriorates and the warning signs to look out for can help you avoid unnecessary repair bills or premature replacement.
How Long Do Windows Last?
Modern double glazed windows generally last 20–25 years, although the exact answer to how long do windows last can vary between different designs. Elements like your chosen material (UPVC, aluminium or timber), the standard of installation, weather-sealing performance, manufacturing quality and routine maintenance all play a role in how long windows remain effective.
Interestingly, traditional single-glazed timber windows can survive for many decades if they’re consistently cared for. The drawback is that their energy performance, insulation strength and resistance to damp are significantly weaker than modern double glazing windows. As a result, opting for double glazed windows is a more sensible and economical choice overall.
What Determines How Long Windows Last?
The following points outline the key elements that can influence window durability and day-to-day performance:
- Local climate
If upkeep is neglected, timber frames and budget UPVC windows are far more prone to wear when consistently subjected to rain, frost, shifting temperatures and damp conditions. - Sunlight exposure
Poor-quality UPVC and timber windows on south-facing sides of a property can fade, warp, become brittle or develop failing seals after prolonged UV exposure. - Coastal locations
Homes near the coast require high-spec window materials and regular maintenance. Salt-laden air increases the risk of corrosion to mechanisms like hinges and locks, as well as frames and sealing systems. - Quality of materials
There is wide variation in the standard of UPVC, aluminium and timber windows. Those with advanced coatings, reinforced profiles and high-performance glazing typically achieve the longest service life. - Skill of installation
Windows that are badly fitted can suffer from draughts, water ingress and premature seal breakdown, regardless of the material used. This significantly shortens their usable lifespan. - Durability of hardware
Handles, locks and hinges are often the first components to fail. Choosing hard-wearing, corrosion-resistant hardware is essential for a window to operate reliably over time. - Ongoing maintenance
Consistent aftercare is vital. This includes regular cleaning, repainting and resealing for timber frames, lubrication of moving parts and routine inspection of seals to keep everything performing as intended.
How Long Can Double Glazed Windows Last?
Double and triple glazing windows generally provide reliable insulation for 15–20 years before the performance of their insulated glass units (IGUs) starts to drop. Premium A-rated units with robust sealing and argon or krypton gas can surpass 20 years, provided they are installed correctly and can withstand harsh conditions.
Typical signs of IGU deterioration include fogging or misting between the panes, caused by a perimeter seal failure that allows moisture in. Condensation inside the glass indicates that the insulating gas has leaked. Failed or damaged seals also reduce insulation and increase heat loss, while draughts along the glazing edge can point to gaps or seal breakdown.
Even when the frame remains solid, these indicators show that the unit itself is losing efficiency.
What Factors Affect Double Glazing Lifespan?
The following elements can shorten the lifespan of double-glazed windows:
- Incorrect Installation
Windows that aren’t fitted correctly may be uneven or poorly sealed, making them susceptible to water penetration and premature seal or frame deterioration. Even top-quality windows require proper installation to function effectively. - Low-quality spacer bars
Spacer bars keep the glass panes apart, but inferior ones can corrode or transfer heat too readily, increasing the risk of condensation and reducing insulation performance. - Thermal Pumping
Glass and frames expand and contract with repeated temperature changes. This “thermal pumping” stresses seals, potentially causing slow gas leakage and eventual failure. - Degrading Sealant
Perimeter sealant secures the panes and maintains insulating gas. UV exposure, extreme temperatures, and chemical wear can degrade the seal over time, leading to fogging, condensation, and less effective insulation. - Atmospheric Pressure Changes
IGU seals can be affected by sudden pressure shifts, particularly in high-rise buildings or regions with extreme weather. This can accelerate seal failure and allow moisture ingress. Windows on south-facing walls are most at risk due to high sun exposure.
How Long Do UPVC Windows Last?
UPVC windows installed today can last 20–35 years or even longer.
Earlier UPVC designs were prone to yellowing and discolouration, but modern variants resist fading and maintain their appearance. They also have enhanced UV resistance, making them less brittle and less likely to crack, while delivering improved energy efficiency.
Modern UPVC requires minimal upkeep. A simple wipe-down with a soft cloth and mild cleaner is usually enough to keep them looking good. Lubricating moving parts occasionally is recommended, but repainting or staining isn’t necessary as it is with timber windows.
High-quality hardware is crucial for UPVC to operate reliably over time, helping to increase the lifespan of UPVC windows. Additionally, integrated steel reinforcement strengthens the frame, helping prevent warping, bending, or other distortions caused by heavy loads or temperature changes.
How Long Do Aluminium Windows Last?
Thermally broken aluminium windows installed today typically last 30–45 years, reflecting their long-term resilience. The thermal break between the inner and outer frames helps prevent heat loss, condensation, and frame warping.
Powder-coated finishes ensure the frame retains a vibrant colour without peeling, fading, or weather-related damage.
Aluminium also resists corrosion thanks to its natural oxide layer, making it ideal for properties near the coast or in areas with challenging weather conditions.
Aluminium windows are low-maintenance: occasional cleaning of the frames and lubrication of moving parts is usually all that’s needed.
How Long Do Timber Windows Last?
Premium timber windows can outperform other materials, usually lasting around 30 years, and with attentive maintenance, some can endure 50–60 years or longer.
Softwood windows, being less dense and more porous, are more susceptible to swelling or rotting from moisture. With adequate protection and routine care, they can last 25–35 years.
Hardwood options such as oak, mahogany, and teak are stronger, denser, and more moisture-resistant. When treated and maintained correctly, their lifespan can reach 50–60+ years.
Regular upkeep (repainting, re-staining, and treating the timber) is essential to protect against rot, warping, moisture, UV exposure, and pest damage.
Neglecting this maintenance can cause even the finest timber to degrade rapidly.
Which Window Frame Lasts the Longest?
The answer to how long should windows last is displayed in table form below, along with some key points to keep in mind…
Feature
UPVC
Aluminium
Timber
Typical lifespan
UPVC 20-35 years
Aluminium 30-45 years
Timber 30-60 years
Durability
UPVC Good
Aluminium Excellent
Timber Very good but only if maintained
Maintenance
UPVC Extremely low
Aluminium Extremely low
Timber High
Thermal quality
UPVC Very good
Aluminium Good to very good
Timber Excellent
Design options
UPVC Fairly limited
Aluminium Very broad
Timber Generally broad
Cost
UPVC Usually, the lowest priced
Aluminium Usually, the highest priced
Timber Mid-range
How long a window lasts depends on the surrounding environment and the quality of its build. It’s entirely possible for a top-quality UPVC window in a favourable setting to surpass the longevity of an inferior aluminium or timber window in challenging conditions.
When Should You Replace Your Windows?
You’ll know when to replace windows in your home if you notice condensation forming inside double- or triple-glazed units, draughts, leaks, difficulty opening or closing, mould or damp on frames, broken seals, or increased heating bills.
Improper installation is a common reason for early replacement, as it can significantly shorten the lifespan of even the best windows.
Problems often arise in situations such as:
- Frames are uneven or not square
- Poor sealing or lack of insulation around window edges
- Loose or insecure fixings
- Gaps behind cills or trims
To emphasise, quality installation is key. Without it, even premium windows won’t perform as intended.
How to Extend the Life of Your Windows
Maintaining your windows is straightforward and helps them last longer. Try these regular checks:
- Clean frames and glass: Wipe away dirt and debris every 2–3 months to prevent staining and keep seals and coatings in good condition.
- Keep moving parts lubricated: Every 6–12 months, lubricate hinges, locks, and other moving parts with a light silicone spray or specialist product to ensure smooth performance.
- Examine seals and gaskets: Look for cracks or gaps twice a year and replace as needed to stop moisture from entering.
- Maintain drainage channels and trickle vents: Remove blockages from leaves, dirt, or insects every 6 months so water can drain properly.
- Watch for damp or mould: Check frames for moisture or mould every 6–12 months to prevent glazing failure or structural issues.
We hope this has given you a clearer answer to how often do windows need to be replaced and what the signs are. If it’s prompted you to consider upgrading, don’t hesitate to give us a call.
If you found this article informative, our piece on windows U-values is also well worth a read.
Want to speak with an Advisor? Give us a call on 01793 781413
Our friendly team will be pleased to help with any questions you may have.
