This is not a case for hiring a professional over doing it yourself. It is the shorter list of things to establish before money moves, because window replacement carries a specific risk that most home improvement work does not: the part that fails is inside the wall, and it does not announce itself for a year or two.
Window and door replacement is also a door-knocking trade, which puts a homeowner into a decision at the seller’s tempo rather than their own. The FTC pattern for that is consistent: a discount available only if you sign right away, a request to pay everything up front, payment demanded by wire transfer, gift card, payment app, cryptocurrency or cash, and a refusal to provide copies of a licence, insurance or a written contract.
Five checks, in the order that costs least
| Check | What you are actually establishing |
|---|---|
| Licence, verified with the issuing body | That the firm exists as it claims. Verify with the state or municipal authority, not from a number read aloud. The FTC lists a refusal to provide licence documentation as a red flag. |
| Certificate of insurance sent by the insurer | General liability and workers compensation, sent directly rather than photocopied from a folder. Without the second, an injury on your property can become your problem. |
| A written specification, not a total | Manufacturer and product line, frame material, glazing package, the whole-unit NFRC rating for that configuration, insert or full-frame, and who supplies trim. Vague product descriptions are how a different window arrives. |
| Who performs the flashing, and how | The detail that keeps water out of the wall. Named in the contract as scope, with a method, or it is nobody’s job. |
| Deposit and payment schedule | A deposit toward materials is ordinary. Payment in full before work starts is not, and the FTC is explicit that if a contractor wants cash up front, the answer is to walk away. |
Row four is the one homeowners almost never raise and the one that determines whether this job causes a problem in three years. Windows are a water-management detail as much as a thermal one. Ask the question in exactly those words: who is doing the flashing, and what method.
If they came to your door, you have three days
The FTC’s Cooling-Off Rule gives a buyer three days to cancel certain sales made at their home, at a workplace or dormitory, or at temporary locations such as a hotel room, convention centre or fairground. The seller must tell you about the right and give you a cancellation form.
That matters here because in-home window sales are exactly the setting the rule was written for, and because a same-evening signature is the tactic it exists to defuse. Knowing the window exists removes the entire force of a discount that expires tonight: sign if you want, then use the three days to verify the licence and the insurance without pressure.
Note the limits rather than relying on it as a universal escape. The rule attaches to particular sales settings, some transactions are excluded, and state law varies and is sometimes more generous. If the sale happened in the seller’s own showroom, do not assume it applies. Keep the paperwork either way, and put any cancellation in writing with a dated copy retained.
The financing conversation is a separate one
A contractor offering to arrange financing is not automatically a problem, but the FTC describes a pattern worth recognising: financing arranged through a lender the contractor knows, papers signed after work starts that may be blank or hurried, and a homeowner who later finds they have agreed to a home equity loan with a high rate, points and fees, on work that is unfinished.
The FTC advice is to never agree to contractor-arranged financing without shopping around and comparing terms, and never to sign a loan you do not understand. One quote from your own bank or credit union is the benchmark that makes the offer legible. It also keeps the seller of the windows from also being the seller of the debt secured against your house.
What belongs in the contract
- Product by manufacturer, line and configuration, with the whole-unit NFRC rating stated. Our note on reading the label covers why a centre-of-glass number is not the same thing.
- Insert or full-frame, named. They are different scopes at different prices, as set out in our note on what moves a bid.
- Flashing method and who performs it.
- Trim, disposal and permit, each present or explicitly excluded, with the contractor pulling the permit.
- Payment stages against completed work, and the workmanship warranty in writing, separate from any manufacturer warranty.
Most window failures in the early years are installation failures rather than product failures, which makes the workmanship warranty the document that matters most and the one most often described verbally. Get its length and its scope on paper.
Questions readers actually ask
How much deposit is reasonable?
A deposit toward materials is ordinary practice, particularly where units are made to order. Payment in full before work begins is not, and a demand for cash up front is a walk-away signal per the FTC. Stage the balance against completed work by a method that leaves a record and can be disputed.
Can I cancel after signing at my kitchen table?
Often yes. The FTC Cooling-Off Rule provides three days to cancel certain sales made at your home or at temporary locations, and the seller must tell you about the right and supply a cancellation form. Exclusions exist and state law varies, so check rather than assume, and cancel in writing with a dated copy kept.
Who is responsible if water gets in later?
Whoever the contract says performed the flashing, which is why it needs naming before work starts. If the contract is silent on it, you are likely to be arguing about scope at exactly the moment you are also dealing with a wet wall. Ask who does the flashing and get the answer in the document.
Should I use the financing the salesperson offers?
Not without shopping it. The FTC advises against contractor-arranged financing without comparing terms, and describes the pattern ending in a home equity loan carrying a high rate, points and fees. Get one quote from your own bank first and use it as the benchmark.
Sources
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Every figure in this article traces to a government record or to a named independent, non-commercial research body. We do not cite insurance marketplaces or affiliate comparison sites for data.
- Federal Trade Commission How To Avoid a Home Improvement Scam Published 2025-12-10Supports: The contractor-arranged financing pattern: financing arranged through a lender the contractor knows, papers signed after work starts that may be blank or hurried, and the homeowner later finding they agreed to a home equity loan with a high interest rate, points and fees on work not done right or not completed; never agree to contractor-arranged financing without shopping around and comparing loan terms, and never sign a loan without understanding the terms; scammers ask the homeowner to obtain any required building permits.
- Federal Trade Commission How To Avoid Scams After Weather Emergencies and Natural Disasters Published 2026-04-28Supports: Warning signs include offering a discount only if you sign a contract right away, asking you to pay everything up front, insisting on payment by wire transfer, gift card, payment app, cryptocurrency or cash, and refusing to provide copies of a licence, insurance or a written contract; if they want cash up front, walk away.
- Federal Trade Commission Buyer's Remorse: The FTC Cooling-Off Rule (16 CFR Part 429) Published 2026-01-01Supports: The Cooling-Off Rule gives a buyer three days to cancel certain sales made at their home, workplace or dormitory, or at temporary locations such as a hotel or motel room, convention centre or fairground; the seller must tell the buyer about the cancellation right and provide a cancellation form. Exclusions apply and state law may differ.
Figures last verified August 30, 2026.