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What Is a Double Glazing Guarantee?

 

A double glazing guarantee is a written commitment from the installer or manufacturer to repair or replace specified components if they fail within an agreed period.

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The guarantee may cover:

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• Window and door frames

• Double glazed sealed units

• Handles, hinges and locks

• Weather seals and gaskets

• Manufacturing defects

• Installation workmanship

• Water penetration caused by faulty installation

• Problems opening or closing the windows

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Some companies use the terms double glazing guarantee and double glazing warranty interchangeably. The wording matters less than the actual protection described in the document.

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Never assume that every part of the window is covered for the same length of time.

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How Long Does a Double Glazing Warranty Last?

 

The length of a double glazing warranty varies between companies, products and individual components.

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An installer may offer a long guarantee on the frame but a shorter period for handles, hinges, locks or decorative finishes. Glass units may also have separate protection against failure of the sealed unit.

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The guarantee should clearly state:

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• Its commencement date

• The length of cover

• The components included

• Parts that have shorter cover

• Any exclusions

• Whether labour and replacement parts are included

• How to report a problem

• Whether the guarantee can be transferred

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A headline such as “ten-year guarantee” can be reassuring, but you should still read the detailed terms to establish what remains protected throughout the full period.

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Double Glazed Window Warranty

 

A double glazed window warranty may combine several different forms of cover.

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Window frames

Frame warranties may protect against manufacturing defects, excessive distortion or faults affecting the frame material.

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Normal colour changes, accidental damage and deterioration caused by unsuitable cleaning products may be excluded.

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Sealed glazing units

A sealed unit warranty usually relates to the failure of the seal between the panes of glass.

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If the seal breaks down, condensation or misting may appear inside the glazing unit. Where this occurs during the warranty period, the failed unit may be replaced while the original frame remains in place.

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Condensation on the room-facing or outside surface of the glass does not necessarily indicate sealed-unit failure and may not be covered.

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Handles, locks and hinges

Window hardware is subject to regular movement and wear. Handles, hinges, locking mechanisms and other operating parts may have a shorter warranty than the window frame.

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Check whether the warranty includes both replacement parts and the labour needed to fit them.

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Installation workmanship

A workmanship guarantee relates to the quality of the installation rather than the manufactured window.

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It may cover problems such as poor alignment, inadequate fixing, defective sealing around the frame or water penetration resulting from faulty installation.

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Manufacturer and Installer Guarantees

 

The window manufacturer and installer may provide separate warranties.

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A manufacturer’s warranty generally covers defects in the products it has supplied. The installer’s guarantee may cover fitting, workmanship and responsibility for arranging repairs.

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Homeowners should establish who must be contacted if a problem occurs. Where the installer purchased the windows from another manufacturer, the homeowner may still be expected to report the fault through the installer.

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Ask for all guarantee documents when the work is completed and keep them with the original contract, invoice and product information.

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What Is an Insurance-Backed Guarantee?

 

A company guarantee normally depends on the installer continuing to trade. An insurance-backed guarantee provides additional protection if the installer ceases trading and can no longer honour an eligible workmanship guarantee.

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Replacement window and door installations registered through FENSA include insurance-backed guarantee protection. FENSA also states that its certificate provides evidence that the installation complies with the relevant Building Regulations and has been registered with the local council.

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Other authorised competent person schemes, including Certass, can also certify replacement window and door installations. An insurance-backed policy may continue eligible guarantee protection where the original installer has stopped trading.

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The policy terms should be checked carefully because insurance-backed protection may not cover every product fault or every promise made by the installer.

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Is a FENSA Certificate a Guarantee?

 

A FENSA certificate and an installer’s guarantee are related documents, but they are not the same thing.

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The FENSA certificate provides evidence that eligible replacement windows or doors have been registered and comply with the relevant Building Regulations. The installer’s written guarantee explains the protection available for the products and workmanship.

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You should therefore receive and retain:

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• The installation contract

• The final invoice

• The installer’s written guarantee

• Any manufacturer warranties

• The insurance-backed guarantee policy

• The FENSA, Certass or other compliance certificate

• Care and maintenance instructions

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These documents may also be requested when the property is sold.

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What May Not Be Covered?

 

Guarantees commonly contain exclusions. These can vary considerably, so the terms should always be read before signing the contract.

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Possible exclusions include:

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• Accidental or deliberate damage

• Damage caused by misuse

• Normal wear and tear

• Failure to maintain moving parts

• Damage caused by structural movement

• Problems resulting from building alterations

• External damage caused by storms or extreme weather

• Scratches reported long after installation

• Condensation not caused by sealed-unit failure

• Repairs completed by another contractor

• Damage caused by unsuitable cleaning materials

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The guarantee may also require the homeowner to report visible damage within a limited period after installation.

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Does a Guarantee Transfer to a New Owner?

 

Some double glazing guarantees can be transferred when the property is sold, while others remain with the original customer.

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Transfer may require:

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• Written notification

• Completion of a transfer form

• Payment of an administration charge

• Transfer within a specified period

• Proof that the windows have been maintained correctly

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A transferable warranty can be valuable when selling a property, but transferability should never be assumed. Check the written terms and keep the documents in a safe place.

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Your Consumer Rights

 

A commercial warranty provides additional contractual protection, but it does not replace your legal rights.

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Under the Consumer Rights Act 2015, products supplied to consumers must be as described, satisfactory in quality and fit for purpose.

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Services must be completed with reasonable care and skill. A business cannot use its warranty wording to remove these statutory rights.

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Where a problem develops, contact the installer promptly and provide photographs, the installation date, contract details and a description of the fault.

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What to Check Before Ordering Windows

 

Before appointing an installer, ask:

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• How long is the overall guarantee?

• Are the frames and glass covered for the same period?

• What protection applies to handles, hinges and locks?

• Are labour and replacement parts included?

• Is the guarantee insurance-backed?

• What happens if the company stops trading?

• Is the warranty transferable?

• Are there servicing or maintenance conditions?

• Which certification documents will be provided?

• How are complaints and repair requests handled?

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The answers should be confirmed in writing rather than relying on statements made during a sales visit.

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Choose Windows with Appropriate Guarantee Protection

 

The quality of the windows and their installation remains important, even where a comprehensive guarantee is provided. A guarantee should offer additional reassurance, not compensate for unsuitable products or poor workmanship.

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APN Double Glazing can connect homeowners with experienced local window installers who can explain the guarantees, warranties and certification available with their products.

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Get in touch for expert advice and a free, no-obligation quote for your new or replacement windows.

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