Window replacement is a big-ticket project, and the industry is full of high-pressure sales tactics — 'today only' discounts, financing games, and install crews you never meet until the day of the job. A handful of specific questions, asked before you sign, separate a legitimate NJ installer from a salesperson. Here are the twelve we'd want a family member to ask, the answers a real contractor gives, and the red flags that mean walk away.
A reputable installer answers all of these easily and in writing. The ones who deflect — especially on license, insurance, and who actually does the installation — are telling you something.
License and insurance — the non-negotiables
What's your NJHIC registration number? Every home-improvement contractor in NJ must be registered with the Division of Consumer Affairs, and the number belongs on your contract. No number, no deal.
Can you email your certificate of insurance? A legitimate installer carries general liability and workers' compensation and can send the certificate within the hour. If an uninsured worker is hurt in your home, the liability can fall on you — so this matters.
Do you have a NJ business address and a local track record? Ask how long they've operated in NJ and for references from recent local jobs. National sales operations and fly-by-night outfits can't always answer this cleanly.
Installation method and who actually installs
Will this be an insert or full-frame replacement — and why for my home? The honest answer is based on inspecting your frames and sills, not a one-size-fits-all script. A contractor who can't explain why one method fits your home hasn't looked closely enough.
Who actually installs — your own crew or subcontracted labor? Either can be acceptable, but you should know, and there should be clear accountability for the workmanship warranty. Some big sales operations sell the job and hand it to whichever sub is cheapest that week.
Do you follow lead-safe practices on older homes? Homes built before 1978 can have lead paint, and window work disturbs it. A legitimate contractor follows EPA RRP lead-safe work practices — containment and proper cleanup — on pre-1978 homes.
Product specifics — what you're actually buying
Exactly what window — brand, line, frame material? 'Premium vinyl' is a red flag; a specific manufacturer and product line is an answer. The same goes for the glass package: Low-E coating, argon fill, and the U-factor and SHGC ratings.
Are the windows custom-sized to my openings? Quality replacements are made to measure for each opening, not forced from stock sizes with filler. Custom sizing is part of why the measurement matters.
What are the NFRC and Energy Star ratings? These are the objective efficiency numbers (U-factor, SHGC) and they determine whether the windows qualify for energy rebates. A real installer provides them.
Warranty — product AND labor
What's the manufacturer's product warranty, and does it cover the glass seal? IGU seal failure (foggy glass) is the most common long-term window problem, so glass-seal coverage matters. Ask how long it lasts and whether it's transferable to a future owner — a transferable warranty is a resale plus.
Is there a separate workmanship (labor) warranty? The product warranty covers the window; the labor warranty covers the installation — and a window installed badly leaks regardless of how good the window is. Ask how long the labor warranty lasts and who services it. A contractor who'll be around to honor it is part of the value.
Process, timeline, and price
Will you give me a written, itemized quote? It should specify the product, glass package, install method, and the price — not a single 'package' number you can't compare to anyone else's.
How is payment structured? A reasonable deposit to order custom windows is normal; a demand for most of the money up front is a red flag. The payment schedule should be in the written contract.
Who handles permits and disposal? Some NJ towns require permits, especially for full-frame work; the contractor should handle that and the removal/disposal of your old windows.
Is there pressure to sign today? High-pressure 'today only' pricing is a sales tactic, not a real discount, and it's especially common in window sales. A legitimate quote holds long enough to compare it. Take 48 hours.
The 12 questions, in one list
Print this and ask all twelve before you sign:
- What's your NJHIC registration number?
- Can you email your certificate of insurance (GL + workers' comp) now?
- How long have you operated in NJ, and can I have local references?
- Insert or full-frame for my home — and why?
- Who installs — your crew or subcontractors?
- Do you follow lead-safe (RRP) practices on pre-1978 homes?
- Exact window brand, line, frame material, and glass package?
- Are the windows custom-sized to my openings, and what are the NFRC/Energy Star ratings?
- What's the manufacturer warranty — does it cover the glass seal, and is it transferable?
- Is there a separate labor/workmanship warranty, and for how long?
- Can I get a written, itemized quote, and what's the payment schedule?
- Who handles permits and old-window disposal?
Red flags — when to walk away
An extreme high-pressure 'sign today for this price' pitch. No NJHIC number, or refusal to provide a certificate of insurance. A demand for a large upfront deposit. Vague product descriptions ('premium vinyl') instead of a specific brand and line. A crew of subcontractors the company won't name or stand behind. A financing-first sales pitch that dances around the actual window price. Any one of these is a reason to slow down; two or more and you should show them the door.