How Long Do Windows Last? (+ When to Replace): 2024 Guide

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Have you looked at your windows recently and wondered if it’s time for an upgrade? As a commercial building owner or Facilities Manager, knowing when to replace your glazing units is important for efficiency, comfort, and budgeting.

Windows don’t last forever, even with regular maintenance and care. At some point, the seals start to fail, air leaks in, condensation forms, and heating or cooling costs skyrocket, begging the question, how long do windows last?

How Long Do Windows Last?

Windows typically have a lifespan of around 15 to 20 years. After this time, the seals may start to weaken or fail, leading to drafts (unwanted air and currents) and water seepage. However, it’s important to note that the lifespan of windows can vary depending on the material used and number of glass panes it contains.

Below are different types of windows and how long they last:

How long do double glazed windows last?

Double-pane windows typically last around 20 years, but this can range from 10 to 35 years. Their lifespan depends on factors such as the quality and type of materials used, how professionally they were installed, and their location. So, while double-glazing insulation properties make them durable and comfortable, it’s important to consider these factors and maintain them properly to maximise their longevity.

How long do timber framed windows last?

High-quality timber windows, including those made from pine, oak, or mahogany, are designed to last. With appropriate care, these windows can easily serve you for up to 60 years and even longer!

Unlike uPVC alternatives (explored below), wooden windows are crafted for easy repair, not replacement, enhancing their environmental friendliness. However, softer woods like pine may show signs of warping or rotting earlier, but vigilant maintenance strategies like painting and caulking can effectively prolong their lifespan.

How long do uPVC windows last?

Vinyl or uPVC (unplasticised polyvinyl chloride) windows are celebrated for their durability and low maintenance. So, how long should vinyl windows last?

These windows typically last around 20 years, but their lifespan can range from 10 to 35 years, depending on the quality and maintenance. If your uPVC windows were installed in the early 2000s, they might probably need replacement or repair. The welded frames and sashes of these windows are less prone to air leaks, and the non-porous vinyl material resists rot and warping.

How long do aluminium windows last?

Aluminium windows are recognised for their durability, low maintenance, and longevity. You can anticipate these windows to last a minimum of 30 years, potentially extending up to 45 years. This impressive lifespan puts them on par with wood and well above uPVC in terms of longevity.

However, it’s worth noting that over time, the metal may dent, frames may become misaligned, or the glazing seal or thermal break may start to fail, which can reduce energy efficiency. Regular maintenance can help prevent these issues.

How long do fibreglass windows last?

Fibreglass windows, reinforced with strong glass fibres, are extremely durable, outperforming vinyl by up to 8 times in strength. These windows are non-conductive, providing excellent insulation and preventing heat transfer. With proper care, fibreglass windows can last for 50 years or longer, significantly longer than the 35-year lifespan of vinyl windows. Moreover, they’re resilient to rot, warping, denting, or scratching, adding to their overall durability.

In summary, most standard windows will last at least 15 to 20 years before needing replacement. But with high-quality materials and proper care and maintenance, many windows can provide an airtight, energy-efficient seal for your building for 40 years or longer. That said, several factors may lengthen or shorten how long windows last, as we’ll see below.

4 Factors That Impact Window Longevity

The lifespan of your windows depends on several factors; some elements you can control, others not so much.

Here are 4 factors that influence how long those panes of glass will last:

  • Weather conditions
  • Window type
  • Installation and maintenance
  • Usage frequency

1. Weather Conditions

The elements your windows are exposed to play a big role. Lots of sun and heat can cause seals and gaskets to deteriorate faster. Similarly, coastal areas with salty sea air also decrease window longevity. On the other hand, windows installed in temperate climates may last a few years longer.

2. Window Type

Double or triple-glazed windows, also known as insulated glass units (IGUs), generally last longer than single-pane. The extra panes provide insulation and help prevent seal failure.

Also, vinyl or fibreglass frames tend to outlast aluminium.

3. Installation and Maintenance

How well your windows were installed and how you care for them affects their lifespan. Proper installation by a glazing professional with high-quality, weather-resistant seals and sealants helps prevent air and water infiltration, which can damage the glazing unit. Performing regular maintenance like lubricating locks and hinges and repairing or replacing weatherstripping when needed keeps everything in working order.

4. Usage Frequency

Windows that remain closed for long periods in vacant buildings or rooms may last longer since they’re not subjected to frequent temperature changes and wear and tear from opening and closing. On the other hand, windows used daily in high-traffic business areas often require replacement sooner.

By properly maintaining your windows, you may be able to squeeze a few extra years out of them. But as a general rule of thumb, if your windows show certain signs, like drafts, difficulty in opening, rot, or other signs discussed in the following section, it’s probably time to consider replacement. The improved energy efficiency and lower utility bills will be worth it!

7 Signs Your Windows Need Replacing

If your window is a double-glazed sealed unit over 10 to 15 years old, inspecting it for signs of failure or damage is a good idea. Waiting too long can lead to costly repairs or replacements down the road.

Some signs of double-glazing failures that indicate it’s time for replacement include:

  1. Condensation or Fogging Between the Panes of Glass: This means the airtight seal has been compromised, reducing the window’s insulation. Check out our guide on how to get rid of condensation between double-glazed windows.
  2. Visible Cracks, Holes or Splits in the Glass or Sash Frames: Any openings can lead to air leaks, reduce security, and may worsen over time.
  3. Difficulty Opening or Closing the Windows: If your windows stick, jam, or require excessive force to operate, the sashes or hardware likely need replacement.
  4. Drafts: If you feel air flowing in around the edges of the window or sill, your windows have probably lost their seal and ability to insulate. This results in higher energy bills and a drafty room.
  5. Peeling or Deteriorating Seals or Weatherstripping: The seals and weatherstripping are what create an airtight barrier and insulation for your windows. Once they start to peel, crack or crumble away, their effectiveness is compromised.
  6. Rot or Water Damage to the Window Sill, Sash or Frame: Excessive exposure to water and other weathering elements can cause wood windows to rot, warp and deteriorate over the years. Aluminium or vinyl may also become dented, discoloured or warped.
  7. Difficulty Keeping Out Noise: Old or damaged windows typically don’t insulate or block sound as effectively. If outside noises are intruding into your building, it may be time for replacement windows with better noise reduction properties.

If you notice any of these issues with your windows, it’s best to have them inspected by a professional to determine whether refurbishment or full replacement is needed to restore performance, efficiency and curb appeal. New high-performance windows can make a world of difference in comfort, energy savings, and building value. This begs the question, how often should you replace your office windows? Let’s find out below!

How Often Should Windows Be Replaced?

Double-glazed units in office buildings typically have a lifespan of 15 to 20 years, depending on their quality and maintenance levels; consider replacing them once they approach this age. As these windows age, the seals may begin to weaken or fail, leading to potential drafts and water seepage, compromising the building’s comfort and energy efficiency.

Notably, single-pane windows, which were standard about 15+ years ago, lack the insulation and energy efficiency of modern double-pane windows. Thus, once these windows start nearing 15 to 20 years of usage or start showing signs of seal failure, it’s prudent to consider upgrading to new, energy-efficient, double-glazed windows to maintain an optimal work environment.

Why Should You Replace Your Old Windows?

When windows show signs of ageing or damage, replacement is often the most cost-effective solution. New, energy-efficient windows will increase comfort, reduce noise, improve the appearance of your offices, and significantly lower utility bills. The cost of custom, high-performance replacement windows may seem steep upfront. Nonetheless, the energy savings and comfort can offset much of the initial investment over the lifetime of the new windows.

For most office caretakers or owners, replacing old or failing double-glazing units and windows every 15 to 20 years is a good rule of thumb to follow for maximum energy efficiency, comfort, and cost savings. But if your windows are still functioning properly and you’re on a tight budget, refurbishing your double-glazing windows or replacing a double-glazed unit desiccant are other options to consider. Certain maintenance practices can help extend the longevity of your window frame and glass unit, as we’ll observe below.

5 Tips for Extending the Lifespan of Your Windows

To get the most life out of your windows, there are a few things you can do. Regular maintenance and minor repairs will keep them working well for years to come.

Here are 5 options to consider:

  • Cleaning
  • Sealing and caulking
  • Lubrication
  • Repairs
  • Protecting

1. Cleaning

Dirt and grime buildup is the number one hindrance to extensive window longevity. Clean your windows at least once a year, more often for larger windows or those in high-traffic areas. Use a soft cloth or squeegee and a mild glass cleaner. For stuck-on debris, use a plastic scraper or scrubber; be very gentle to avoid scratching the glass.

2. Sealing and Caulking

Check the caulk and weatherstripping around the edges of your double-glazed sealed units for any cracks or gaps, and reseal them. Air and water leaks are damaging and reduce energy efficiency. Re-caulk or apply weatherstripping tape as needed.

3. Lubrication

Ensure any moving parts like locks, hinges or sliders are lubricated to prevent sticking. A spray-on lubricant or lightweight oil works well for most window hardware. This helps prevent excess force being used to open or close the window which can lead to breaks or cracks.

4. Repairs

Address any minor damage like cracked glass, broken locks, or torn screens right away before the problem worsens. For small cracks in glass, apply a glass repair resin or tape. Have larger cracks, broken seals or other issues evaluated by a professional window replacement company to determine if a full replacement is needed or if spot repairs will do.

5. Protection

Use a sealant or protective film like UV-resistant acrylic to shield glass from environmental damage. This is especially useful for windows facing south or west. Protective glazing or films block up to 99% of UV rays, which are harmful to both glass and any coatings like low-E layers. They also reduce heat and glare.

With regular maintenance, you can keep your windows clear, sealed and working properly for more than the average 20 years before needing full replacements. Address any issues, and your windows will continue serving you well for a long time.

Frequently Asked Questions

Can windows last 30 years?

Absolutely, windows can last for 30 years, or even longer, when properly installed and maintained. This longevity is especially true for commercial windows, which are designed to be a durable investment for business properties. However, the lifespan of windows depends on several factors, including the quality of materials, installation process, climate, and maintenance routine. So, while a 20 to 30-year lifespan is typical, with premium materials and meticulous care, these windows can often exceed that range.

How do I know if my windows need replacing?

Determining if your windows need replacing often comes down to keen observation. Look out for noticeable chips or cracks in the windowpane. These defects not only impact the appeal/beauty of your windows but can also lead to draughts, leaks, and persistent condensation issues.

If such problems are a regular occurrence, it’s a strong indication that your windows likely need replacing. Remember, timely replacement can enhance your building’s energy efficiency, comfort, and overall aesthetic appeal.

How efficient are 20-year-old windows?

Windows that are 20 years old may not be as energy efficient as current window options. While they’ve served their purpose, older models often feature single-pane glass, which doesn’t insulate as much as modern windows with the double-pane design — with insulating argon gas found in newer options. As a result, these ageing windows might be letting in drafts or allowing heat to escape more than newer models would.

Upgrading to modern windows can improve your building’s insulation, comfort, and energy efficiency, potentially saving you money on energy bills.

Is it worth replacing 20-year-old double glazing?

Yes, it’s often worth replacing 20-year-old double glazing. Modern double glazing can reduce heat loss and increase energy efficiency by up to 25%, translating into savings on your energy bills.

These newer versions of modern double-glazed windows not only improve your office’s temperature regulation, keeping it warm in winter and cool in summer, but they also provide better insulation against outside noise. So, an upgrade can significantly enhance employees’ productivity through the added comfort, making it a worthwhile investment.


So, how long do windows last? In summary, 20 to 35 years.

While high-quality windows can last for decades with proper maintenance, even the best units won’t last forever. Keep an eye out for signs of damage or reduced performance, and don’t hesitate to call in a glazing professional if you have concerns.

When installed by an experienced glazing company like GLRE, replacement windows are an investment you’ll enjoy for years to come. The choice is clear — if your windows have served you well but are past their prime, now is the time for an upgrade. Contact GLRE now!

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