Window Warranties Explained: Full, Limited and Lifetime

A written warranty on replacement windows is governed by the federal Magnuson-Moss Warranty Act. That means it must be titled “full” or “limited” and must spell out, in one document, who is covered, what is covered and how to make a claim. The word “lifetime” has no fixed meaning; the Federal Trade Commission’s guides say an ad using it should state whose life, or which life, sets the term.

Are replacement windows covered by federal warranty law?

Usually, yes. The Act applies to consumer products, and the FTC’s interpretation (16 CFR 700.1) settles how building materials fit:

Covered: building materials sold over the counter, and materials a consumer buys under a contract to improve, repair or modify a home. The FTC’s own examples include siding, roofing, storm windows and remodeling.
Not covered: windows and other components already built into a house when it is sold as real estate with a written warranty.
Not covered: materials used when a consumer hires a builder to construct a home or a substantial addition, because the contract is for realty.

So a window replacement contract generally falls under the Act, while the windows in a newly built house bought with the house generally do not.

Full versus limited

The title is a shorthand the law defines. The FTC’s guide explains that a “full warranty” meets federal minimum standards for warranty coverage, and a “limited warranty” does not meet at least one of them.

A full warranty has these features, according to the FTC:

Every owner. Service goes to anyone who owns the product during the warranty period, not only the first buyer.
No time limit on implied warranties. The warrantor cannot shorten them.
Service paid by the warrantor. Under a full warranty, the warrantor, not the owner, pays for warranty service.
Reasonable duties only. Requiring customers to return a registration card is, in the FTC’s words, an unreasonable duty that is not allowed in a full warranty.
Refund or replacement. If the product cannot be repaired after a reasonable number of tries, the consumer chooses between a replacement and a full refund.

A limited warranty can require the owner to pay for labor or return a registration card, and it can cut implied warranties off when the written term ends. A warranty can also be part full and part limited. The FTC’s example is a full two-year warranty on a clothes washer, followed by a limited warranty on parts for the third through fifth years.

Implied warranties come from state law, not from the document. The FTC notes that a warrantor who offers a written warranty cannot disclaim them. It adds that state statutes of limitations for warranty claims are generally four years from the date of purchase.

What the warranty document must tell you

Under 16 CFR 701.3, a written warranty must disclose, clearly and in one document:

who the warranty covers, if it is limited to the original buyer or otherwise does not cover every owner during its term;
which products, parts or characteristics are covered and, where needed, which are excluded;
what the warrantor will do about a defect, including what it will and will not pay for or provide;
when coverage starts, if not on the purchase date, and how long it lasts;
a step-by-step claim procedure, including who is authorized to perform warranty work and how to reach the warrantor;
any informal dispute settlement program;
any limit on the duration of implied warranties or exclusion of incidental or consequential damages, with a notice that some states do not allow such limits.

The FTC’s Pre-Sale Availability Rule requires sellers to make written warranties available where warranted products are sold, so buyers can read them before buying. A seller that relies on a manufacturer’s warranty must still make copies of it available.

What “lifetime” can mean

Applied to windows, “lifetime” can mean the life of the house, the time the original buyer owns it, or the original buyer’s own life. The FTC’s guide describes all three uses:

The life of the thing the product is installed in. Coverage transfers to later owners and lasts as long as that item lasts.
As long as the original buyer owns it. The FTC calls this use common but an inaccurate application of the term.
As long as the original buyer lives. The FTC describes this as probably the least common usage.

The FTC’s advertising guides (16 CFR 239.4) say that an ad using “lifetime” or “life” to describe a warranty should disclose clearly which life it refers to.

For windows, the practical question is whether coverage ends when the house is sold. The document has to say so if coverage is limited to the original buyer.

Glass, frame, finish and labor are often separate

ENERGY STAR’s buying guidance tells shoppers to ask about both the window product warranty and the installation warranty, and gives separate benchmarks for different parts of the coverage:

Window product: at least 10 years, and preferably 20 years or “lifetime,” however that is defined.
Glass seal: at least 10 years, and preferably 20.
Wood finishes and installation: typically less than 5 years.

A manufacturer’s warranty on the window and an installer’s promise about the installation can come from two different companies with two different claim procedures. The FTC also distinguishes warranties, which come with a product, from service contracts, which are optional agreements for product service bought separately.

When to bring in a professional, and what to ask

Read the actual warranty documents before signing a window contract, not a summary in a brochure. Questions to put to the seller or installer:

Who is the warrantor for the glass, the frame, the hardware, the finish and the installation? Is each one full or limited?
If any term is “lifetime,” whose life measures it, and does it end when the house is sold?
Does the warranty transfer to the next owner, and what notice or registration does that require?
Is labor covered, or only parts?
Is registration required, and by what deadline?
What is excluded, and what could void coverage?
What is the step-by-step procedure for a claim, and who performs the work?
Can I have copies of every written warranty now, before I sign?

The FTC notes that the Act lets consumers who win a warranty lawsuit recover court costs and reasonable attorneys’ fees. This page is general information, not legal advice. For a dispute, a state consumer protection office or an attorney can review the specific documents.

Keep the warranty papers, the invoice and each window’s NFRC label. ENERGY STAR advises telling the installer explicitly to keep each window’s NFRC label for the homeowner.