When investing in double glazed windows for your home or business, one of the most common questions is, “How long do they last?” The good news is that high-quality double glazing is built to go the distance — offering exceptional performance, low maintenance, and long-term value. In this blog, we explore what impacts the lifespan of double glazed windows, how to keep them in top condition, and when it might be time for a replacement.
✅ What is the Typical Lifespan of Double Glazed Windows?
On average, well-manufactured double glazed windows can last 20 to 35 years or more, depending on the materials used, environmental conditions, and how well they’re maintained. At Forever Green Windows, we use premium Deceuninck uPVC profiles, known for their durability and energy efficiency. Combined with expert manufacturing at our facility in Gregory Hills, you can expect a window system that stands the test of time in Australian conditions.
What Affects the Lifespan of Double Glazing?
Several factors influence how long your windows will last:
1. Quality of Materials
Not all double glazed units are created equal. Cheap or poorly assembled units can fail in less than 10 years. Our use of high-performance uPVC frames and double glazed glass units ensures your windows remain strong, weather-resistant, and energy-efficient over the long term.
2. Manufacturing Standards
Windows manufactured locally in Australia are better suited to handle our unique climate conditions. Our windows are custom-made in Gregory Hills, which allows us to maintain complete quality control and provide products specifically engineered for Australian homes.
3. Installation Quality
Poor installation is one of the leading causes of premature window failure. While Forever Green Windows is a supply-only company, we’ve built a trusted network of skilled installers who can ensure your windows are fitted correctly. For new builds, we also offer a partial installation service, where builders install the reveals and frames, and we complete the critical finishing stages — glazing, flyscreens, and handles.
4. Climate Conditions
Sydney’s climate ranges from intense sun to coastal humidity and strong winds. uPVC double glazed windows are ideal for these conditions because they don’t warp, rot, or corrode like timber or aluminium alternatives.
Are Double Glazed Windows Low Maintenance?
Yes — one of the best things about uPVC double glazed windows is how little upkeep they require.
Cleaning: A simple wipe-down with mild soapy water is all that’s needed.
Lubrication: Hinges and locks may need a light oiling once or twice a year.
Seals: Check the rubber seals occasionally for wear — though with quality products, these rarely need replacing.
Our windows are designed for minimal fuss, giving you peace of mind for years to come.
When Should You Consider Replacing Double Glazed Windows?
Although they’re built to last, no window lasts forever. Here are signs it might be time to replace them:
Condensation Between Panes: This suggests the seal has failed and the insulating properties are compromised.
Noticeable Draughts: You shouldn’t feel cold air coming in around the frames or sashes.
Visible Damage or Warping: While uPVC is highly durable, extreme impacts or long-term UV exposure may eventually degrade the material.
Outdated Designs: If your windows are more than 20 years old, upgrading could dramatically improve your home’s thermal performance, security, and aesthetics.
️ Is There a Warranty?
Yes — all our double glazed windows and uPVC frames come with a comprehensive 10-year warranty, covering everything from the sealed units and hardware to workmanship and materials. This means you’re protected in the rare event that something does go wrong.
How Long Will They Last in My Home?
If your windows are:
Manufactured from high-quality uPVC
Professionally installed
Properly maintained
… then you can realistically expect them to last 30 years or more.
We regularly work with homeowners, builders, and architects across Sydney who are looking for long-term, energy-efficient window solutions. Our clients choose Forever Green Windows for the combination of premium materials, local manufacturing, and exceptional service.
Got Questions? We’re Here to Help
Want to know more about the longevity of our windows or what product is right for your home? Whether you’re building new or replacing existing windows, contact Gary Saunders and the team at Forever Green Windows today. We’ll guide you through your options and help you invest with confidence.
