White uPVC windows with glazing bars and a brick surround

uPVC windows typically last 20 to 25 years, and well-made frames that owners maintain can last longer. However, bad weather or poor fitting can shorten that life, so some windows need replacing sooner.

Also, the frame is only half the story. The sealed glass units inside it can fail before the frame does, which is why windows often look fine but still start to mist up.

uPVC windows with glazing bars on a brick house, showing how long uPVC windows last

How long do uPVC windows last compared with other frames?

First, compare the three main frame materials. Timber and aluminium usually outlast uPVC, but they also cost more.

Frame material Typical lifespan
uPVC 20–25 years
Timber 30–40 years (with regular sealing and painting)
Aluminium Up to 30–45 years (high-quality frames)

Across all types, experts commonly quote 25 to 30 years for double glazing on average. In exposed, extreme-weather locations, however, that drops closer to 20 years. Source: Homebuilding & Renovating.

What shortens how long uPVC windows last?

Several things wear windows out faster. For example, you can avoid most of them with good fitting and a little care.

  • Poor installation, because frames that sit out of square strain the glass and seals.
  • Weather exposure, since strong sun, driving rain and coastal air wear down seals and hardware.
  • Low-quality frames or glass units, which tend to fail earlier.
  • No maintenance, as dirty seals, dry hinges and blocked drainage slots all speed up wear.
  • Damage, because knocks, forced locks or heat can warp the frame.

4 signs your windows are failing

  1. Draughts. A cold breeze near a closed window usually means the seals have worn out.
  2. Condensation between the panes. This means the sealed unit has failed, so read our guide to misted double glazing.
  3. More outside noise, because the insulating gas may have escaped.
  4. Visible frame damage. Warping, cracks, chips or yellowing in the uPVC all point to an ageing frame.

How to make uPVC windows last longer

Simple habits add years to your windows. First, inspect the frames and seals once a year. Then follow these steps:

  • Wipe the frames and seals with warm soapy water, and avoid abrasive or solvent-based cleaners.
  • Also keep the drainage slots at the bottom of the frame clear.
  • Lubricate the hinges and locks once a year.
  • Finally, fix small problems early, such as a loose handle or a worn seal.

Repair or replace?

If only one or two sealed units have failed and the frames are sound, replacing the units is usually cheaper. However, if the frames are warped, the hardware is failing or the windows are over 20 years old and draughty, replacement gives better value. Check typical prices in our double glazing cost guide.

Need a professional opinion?

Faron Home Improvements is FENSA-registered, and we supply and fit our window installation service across Sussex, Surrey and Kent. So call 01342 643075 or request a free survey, and we will tell you honestly whether your windows need repairing or replacing.

How long do uPVC windows last? FAQs

How long do uPVC windows last before they need replacing?

They typically last 20 to 25 years. However, good-quality windows with regular care can last longer, while poor installation or harsh weather can shorten their life.

Do double glazed windows lose their effectiveness over time?

Yes. As the seals age, insulating gas escapes and moisture gets in. As a result, thermal and sound insulation both drop.

Why are my 10-year-old windows misting up?

Misting between the panes means the unit’s seal has failed. Poor installation, worn sealant or frame movement often cause this, so it can happen well before the frame itself wears out.

Do uPVC windows turn yellow?

Older or low-quality uPVC can yellow with UV exposure. However, newer frames resist it better, and yellowing signals age rather than a safety problem.

Is it worth repairing 20-year-old windows?

Only if the frames are still straight and sound. If the windows are draughty, misted and worn, replacement usually gives better long-term value.

What is the lifespan of double glazing glass units?

Sealed units often last 15 to 25 years, depending on quality and conditions. Because the seal is the weak point, units sometimes fail before the frame does.

Do uPVC windows need maintenance?

Yes, but very little. For example, you only need to clean the frames, clear the drainage slots and lubricate the hinges once a year.

Do uPVC windows last longer than timber?

No. Well-kept timber windows often last 30 to 40 years, while uPVC lasts 20 to 25. However, uPVC needs far less upkeep, so many homeowners still prefer it.

When should I replace my windows?

Replace them when you notice persistent draughts, misting in several units, damaged frames or rising heating bills. In addition, a free survey will show you exactly what your windows need.

Does the guarantee cover the lifespan of the window?

Not usually. Guarantees typically cover 10 years or so, which is shorter than the window’s working life. So check what yours covers before you rely on it.

Related guides and local services

Read more about windows and glazing from Faron Home Improvements:

Last updated: October 2026.