The industry standard warranty for new windows and doors in the UK is 10 years, though specific terms vary by installer and product type. The GGF (Glass and Glazing Federation) recommends a minimum 10‑year insurance‑backed guarantee for consumer protection (BRE, 2026).
The length of warranty depends on whether you are buying from a national manufacturer, a local installer, or a DIY supplier. A 10‑year guarantee is typical for fully fitted double‑glazed units from FENSA‑registered or TrustMark‑accredited companies. However, the warranty often splits into separate cover for the glass, the frame, and the hardware (handles, hinges, locks). You must check the small print – some warranties reduce to 5 years for moving parts or exclude labour after year 2.
Standard 10‑year warranty covers the sealed unit and frame
Most reputable installers offer a 10‑year guarantee on the double‑glazed sealed unit against misting or gas loss, and a 10‑year structural guarantee on the frame (uPVC, aluminium, or timber). The GGF states that a 10‑year insurance‑backed warranty protects you if the installer goes out of business (FENSA, 2026). For example, a typical uPVC window from a FENSA‑registered company includes a 10‑year guarantee on the profile and the glass unit, but only a 2‑year guarantee on the handle mechanism. Always request the full warranty document before signing.
Shorter warranties apply to hardware and labour
Even with a 10‑year product warranty, the labour to replace a faulty handle or hinge is often covered for just 1 to 2 years. Energy Saving Trust notes that warranties on moving parts like friction stays and espagnolette locks typically run for 2 to 5 years (Energy Saving Trust, 2026). If a door lock fails after 3 years, you may pay for the call‑out fee and fitting, while the replacement part is free. Some premium aluminium door systems offer a 10‑year hardware warranty, but this is less common for uPVC. Check whether the warranty is “parts only” or “parts and labour” before you compare quotes.
DIY and online‑bought windows have shorter cover
If you buy windows or doors from a builder’s merchant or online retailer and install them yourself, the warranty typically drops to 5 years for the glass and 2 years for the frame. MCSCertified states that self‑installed products void the insurance‑backed guarantee because there is no certified installer to back the workmanship (MCSCertified, 2026). For example, a standard uPVC door bought online may carry a 5‑year glass warranty and a 1‑year hardware warranty. To get the full 10‑year cover, you must use a FENSA‑registered or TrustMark‑accredited installer who provides an insurance‑backed guarantee. This also protects you if the company closes down.
A worked example
A typical replacement of 8 double-glazed uPVC windows and a composite front door on a 1930s semi-detached house in the Midlands will cost around £7,500 fully fitted. With the 0% VAT rate on energy-saving materials extended until March 2027, you save approximately £1,500 in tax. If you qualify for the ECO4 scheme or the Great British Insulation Scheme, your upfront cost could drop further. The Energy Saving Trust estimates these upgrades cut annual heating bills by £200 to £300 for a gas-heated home. The 10-year structural warranty covers the frames and sealed units, but the hardware (handles, hinges, locks) typically carries only a 2-year labour guarantee. Replacing a faulty handle after year 3 could cost £80 to £150, so check the small print before signing. An insurance-backed guarantee from a GGF-registered installer protects you if the company ceases trading.
| Item | Figure |
|---|---|
| Upfront cost after grants | £6,000 |
| Yearly savings | £250 |
| Payback period | 24 years |
| 25-year lifetime savings | £6,250 |
What homeowners often get wrong
The most common mistake is assuming the 10-year warranty covers absolutely everything on the window or door. The warranty is typically split into separate cover for different components, and many homeowners discover this only when a repair is needed.
- Confusing structural and hardware cover The frame and sealed unit usually have a 10-year guarantee, but handles, hinges, and locking mechanisms often reduce to 2 to 5 years. Replacing a broken handle yourself can cost £40, but calling out the original installer after year 3 could mean an unexpected £120 labour charge.
- Ignoring the labour clause Many warranties cover the cost of replacement parts but not the labour to fit them after the first 2 years. This can add £200 to £400 to a claim for a misted sealed unit, effectively voiding the financial benefit of the 10-year guarantee.
- Failing to register the warranty Some manufacturers require you to register the product online within 30 days of installation. Missing this deadline can void the entire guarantee, leaving you with no cover at all for a £7,500 investment.
Quick reference
- A standard 10-year warranty from a FENSA-registered or TrustMark-accredited installer covers the sealed unit and frame against manufacturing defects and misting.
- Hardware components such as handles, hinges, and locks typically carry a separate warranty of 2 to 5 years, not the full 10 years.
- To qualify for the full warranty, the installation must comply with Building Regulations and be carried out by a certified installer registered with FENSA, CERTASS, or a similar body.
- An insurance-backed guarantee from the GGF costs around £50 per installation and protects you if the installer goes out of business before the 10-year term ends.
- Misting inside the double-glazed unit is covered under the 10-year warranty, but damage from accidental impact or DIY drilling through the frame is not.
Frequently Asked Questions
The standard warranty is 10 years for the sealed unit and frame. The GGF recommends a minimum 10-year insurance-backed guarantee for consumer protection.
No, hardware like handles and hinges typically has a 2-year warranty, and labour cover may end after year 2. Check the small print with your installer.
An insurance-backed guarantee from a FENSA or TrustMark registered company protects you. The GGF advises this cover to ensure repairs are still honoured.
