How Long Do Windows Last in the UK? Full Guide
How Long Do Windows Last by Window Type?
- UPVC windows:
Typically deliver around 20–30 years of service, sometimes stretching to 35 years when well installed and routinely maintained. - Aluminium windows:
Often reach 30–45 years thanks to their robust construction and resistance to warping, swelling and cracking. - Timber windows:
Commonly last 30–40 years, though with consistent care and upkeep, 60 years or more is achievable.
Gaining a clearer idea of how long windows last is beneficial for homeowners, particularly when it comes to insulation levels, heating costs and potential damp issues. Once draughts, moisture or persistent condensation start to appear, it can become harder and more expensive to keep your property warm. Underperforming windows may even influence your home’s market value.
Each window material, UPVC, aluminium and timber, has its own lifespan and ageing process. Understanding how each type wears over time, alongside the warning signs of deterioration, can help you to understand how long should windows last so you can avoid costly repairs or replacements.
How Long Do Windows Usually Last?
Most modern double glazed windows provide reliable performance for around 20–25 years, though this figure can vary depending on the material chosen. Window longevity is shaped by the frame material, installation quality, exposure to the elements, manufacturing standard and ongoing upkeep.
Interestingly, older single-glazed units can survive for many decades with careful maintenance. However, their insulation levels and resistance to moisture fall short of today’s double glazing windows, making upgrading the more sensible long-term decision.
What Affects Window Lifespan?
The following factors play a major role in how long your windows remain functional:
- Weather exposure
Timber frames and economical UPVC options are more vulnerable to wear if they face regular rain, frost, humidity and fluctuating temperatures without proper care. - Sun intensity
Lower-grade UPVC or timber on sun-heavy elevations can fade, crack, weaken or experience seal failure due to intense UV exposure. - Coastal climates
Homes near the sea need higher-spec frames and more frequent maintenance. Salt in the air can corrode metal components and wear down seals far faster than inland conditions. - Material grade
Not all window products are created equal. Frames with enhanced coatings, reinforced profiles and advanced glazing tend to last significantly longer. - Installation quality
Even premium windows will fall short if fitted incorrectly. Poor installation can allow draughts, water entry and premature seal failure. - Hardware strength
Hinges, handles and locks often wear out before the frames themselves. Rust-resistant, sturdy hardware helps prolong performance. - Care and maintenance
Cleaning, lubrication, and, for timber, regular repainting or re-treating all play a crucial role in extending a window’s lifespan.
How Long Do Double Glazed Windows Last?
Double and triple glazing windows typically maintain strong insulation for 15–20 years before the sealed unit begins to decline.
High-grade, A-rated IGUs filled with argon or krypton gas may last even longer, assuming they’re fitted professionally and built to withstand challenging weather.
Signs that a double glazed unit is failing include fogging or misting between the panes, internal condensation, weakening seals or noticeable draughts around the glazing edge.
These issues often indicate gas loss, moisture entry or perimeter seal failure, even if the frame itself still looks sound.
What Factors Affect Double Glazing Lifespan?
There are a few things that can shorten the lifespan of double-glazed windows:
- Substandard Installation
If a window is misaligned, inadequately sealed or poorly anchored, water ingress and early failure become much more likely, even on an otherwise excellent product, which is why we recommend you come to us for windows South Wales. - L0w-quality spacer bars
Spacer bars keep the panes apart. Inferior bars can corrode or conduct excess heat, increasing condensation risk and reducing thermal performance. - Thermal Pumping
Repeated heating and cooling cycles cause the frame and glass to expand and contract, placing pressure on seals and sometimes allowing gas to escape over time. - Sealant Breakdown
The perimeter sealant can weaken due to UV exposure, extreme temperatures or chemical wear. As it degrades, fogging and condensation begin to appear. - Pressure Fluctuations
Sudden atmospheric pressure changes, common in high-rise buildings or areas with variable weather, can strain IGU seals and accelerate failure. South-facing windows are especially at risk.
How Long Do UPVC Windows Last?
Modern UPVC windows generally endure for 20–35 years, and the lifespan of UPVC windows is sometimes longer, depending on build quality and maintenance.
Older UPVC profiles had a tendency to yellow or discolour, but contemporary formulations offer far better UV resistance and colour stability. They’re also less prone to brittleness, cracking or warp-related distortion.
Maintenance is minimal: a quick wash with mild detergent keeps frames in good condition. Hardware may need occasional lubrication, but unlike timber, UPVC never requires painting or staining.
Long-lasting UPVC windows also depend on strong internal reinforcement and durable hardware to maintain structure and smooth operation.
How Long Do Aluminium Windows Last?
Today’s thermally broken aluminium frames usually last 30–45 years, owing to their exceptional strength. The thermal break improves insulation, minimises condensation and helps the frame withstand temperature changes without distortion.
Powder-coated finishes create a tough outer layer that resists fading, peeling and general weathering, while aluminium’s natural oxide barrier protects against corrosion. This makes it especially suited to harsh weather zones and coastal regions.
Ongoing care is simple: regularly clean the frame of your aluminium windows and lubricate any moving parts to ensure continued smooth function.
How Long Do Wooden Windows Last?
High-quality timber windows typically offer around 30 years of service life, but with proper treatment, they can reach 50–60 years or beyond.
Softwood frames are lighter and more porous, making them more susceptible to swelling or rot unless well protected. With routine care, 25–35 years is normal.
Hardwoods like oak, teak and mahogany are denser and more resilient. With good upkeep, they often exceed 50–60 years.
Maintenance is crucial: regular sanding, staining, painting and treating protects against moisture intrusion, UV exposure, pests and general decay. Without upkeep, even premium timber can deteriorate quickly.
Which Window Frame Material Lasts the Longest?
A comparison of the most common materials for different types of windows for homes in South Wales is shown below, along with key points to note:
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 both the climate it faces and how well it was manufactured. It’s entirely possible for a superior UPVC window in a sheltered environment to last far longer than a poorly built aluminium or timber window subjected to harsher conditions.
When Should You Replace Your Windows?
Common signs it’s time to replace your windows include moisture or fogging inside double- or triple-glazed units, draughts, stiff operation, damp or mould forming around frames, broken seals and increased heating bills.
Installation issues can cause early window failure, sometimes years ahead of when replacement should be necessary. Indicators include:
- Frames that aren’t level or correctly aligned
- Insufficient sealing or insulation around the edges
- Loose or poorly secured fixings
- Gaps behind trims or cills
As mentioned, even premium windows can underperform if they’re not fitted to a professional standard.
How to Prolong the Life of Your Windows
A few simple, regular checks can significantly extend window lifespan:
- Clean frames and glass: Remove grime every 2–3 months to avoid staining and reduce wear on coatings and seals.
- Lubricate hinges and hardware: Apply a silicone spray or specialist lubricant every 6–12 months to keep moving parts functioning smoothly.
- Check seals and gaskets: Inspect them twice a year and replace any cracked or damaged sections to prevent moisture ingress.
- Clear drainage routes: Remove any debris from trickle vents and drainage channels every six months so water can flow freely.
- Watch for damp or mould: Inspect frames periodically to catch any moisture problems early.
- Use the windows frequently: Regular operation prevents stiffness and helps you spot issues before they escalate.
We hope this guide has given you a clearer understanding of how often do windows need to be replaced and what signs to watch for when to replace windows. If it’s encouraged you to think about upgrading, we’re always here to help.
If you found this article useful, our guide on what is a good U-value for windows is also well worth a read.
Request your Free Quote
Simply fill in your details for your free, no obligation quotation, and click "Get Quote"