The questions to ask a window company (before you sign anything)

The appointment is on the calendar. Somewhere in the back of your mind is the worry that you’ll sit through a long presentation, get to a number that expires at midnight, and sign something before you’ve had time to think.

Here’s the good news: you don’t need to win an argument. You need a handful of calm questions and a pen.

I write and measure these quotes for a living. Below are the exact questions I’d ask if I were sitting on your side of the table — grouped by what each answer actually tells you.

What should I ask a window company before I sign? Ask questions in four groups. The window: brand, line, U-factor, SHGC, and glass package, in writing. The install: who does it, insert or full-frame, and what happens if they find rot. The warranty: the product warranty AND the labor warranty, separately. The price: itemized, and whether it’s still good next week. A company expecting to win can answer all four without blinking.

What should I actually ask a window company?

Ask questions that make the quote name itself. A vague quote survives on adjectives — “premium,” “top-of-the-line,” “lifetime.” A comparable quote survives on nouns and numbers: a brand, a line, a U-factor, a payment schedule.

Every question below does one job — it turns an adjective into something you can write down and compare against the next company’s answer. None of them is confrontational. They’re the questions any good rep can answer in a sentence.

The questions about the window itself

Make the window tell you its name and its numbers. “A great window” is not a spec. A brand, a line, and the two NFRCNational Fenestration Rating Council numbers off the label are.

• “What’s the brand and line — the exact model?” ENERGY STAR’s own buying guidance says an estimate should name the brand and model, not just a category.
• “What’s the U-factor and SHGC on this window, in writing?” These are the two numbers that tell you how the window performs in our climate. If a quote can’t produce them, it can’t be compared to anything. Here’s how to read them off the label.
• “What’s in the glass package?” Low-Elow-emissivity coating, argon fill, double- or triple-pane. In most of North Carolina the coatings that manage summer heat matter more than chasing the lowest number.

The questions about the install

The window is half the purchase. The install is the other half — and it’s the half that leaks a year later. A great window sealed badly still lets water into the wall.

• “Who actually installs it — your crews or subcontractors?” Either can be excellent. You’re just establishing who stands behind the work and who you’ll call if something’s off.
• “Is this an insert or a full-frame replacement?” An insert drops the new window into your sound existing frame. A full-frame tears back to the rough opening — the right call when the sill or surrounding wood is rotted. They’re different jobs at different prices, and you want to know which one you’re buying.
• “What happens if you open it up and find rot?” This is the question that separates a firm price from a surprise. A company that handles this routinely will tell you exactly how a change gets priced before they proceed.

The questions about the warranty

There are two warranties, on two different clocks — and homeowners get hurt by conflating them. The manufacturer covers the product. The installer covers the workmanship.

• “What’s the product warranty AND the labor warranty — separately, in writing?” The product warranty runs long (often 10–25 years by component). The labor warranty is frequently just one to several years, and an install fault is the more common early failure.
• “When the fine print says ‘lifetime,’ whose lifetime, and which parts?” “Lifetime” usually means the product’s expected lifespan, not yours, and it’s often split — frame, glass, and hardware on different clocks. The FTC requires the term be defined, so ask to see the definition.
• “Is it transferable if I sell the house?” A transferable warranty adds resale value, but it often requires written notice within a set window and may prorate after transfer. Worth knowing now, not at closing.

The questions about the price and terms

Re-anchor every conversation on the total project cost, itemized — not the monthly payment. “Just $200 a month” answers a different question than “what does this cost.”

• “Can I get this itemized, line by line?” Each window unit, labor, trim and sealants, old-window disposal, permits, both warranties, and a timeline. A revised itemized quote is a normal request, not a difficult one.
• “Is this price good next week?” A real number for real work is still real in seven days. The CFPBConsumer Financial Protection Bureau lists offers that are “only good today” among its classic warning signs to slow down on.
• “What’s the deposit, and what triggers each payment after it?” North Carolina sets no statutory cap on home-improvement deposits — it’s negotiated. Consumer-protection guidance commonly points to a modest deposit (often cited around 10%) with the rest tied to milestones; a request for 50% or more upfront is a commonly cited caution worth asking about.
• “What’s the cash price versus the financed total?” If financing is on the table, ask whether a “0% APRannual percentage rate” offer is true 0% or a deferred-interest plan — the honest financing picture is here.

The one question about the company

“Who answers the phone in year three?” A window is a decade-plus purchase. The company that installs it should still be reachable when a sash needs adjusting or a seal fails under warranty.

Two quick ones that go with it: “Can I see a couple of recent local jobs or references?” and “Who pulls the permit, and is it a line item?” In North Carolina, permit handling turns on scope and the state’s $40,000 threshold — who pulls the permit is covered here. You’re not checking the code. You’re checking whether the company handles it openly.

What a clear answer sounds like (and what deserves one more question)

A confident quote answers in nouns and numbers. A shaky one answers in adjectives. That’s the whole tell — and it’s a comment on the answer, never on the person giving it.

Hold each answer you get against this. Where the middle column lands, you’re set. Where the right column lands, you’ve just found your next question.

Copy these into your phone

Here’s the whole page as a list you can read back at the table. No memorizing. Pull out your phone, read them one at a time, and write down what you hear.

Once you’ve got answers from two or three companies in that shape, the comparison almost runs itself: normalize each to a per-window installed price and sanity-check the number against NC ranges, then overlay the quote red flags to see what’s missing. The full buyer’s playbook ties it all together.

And if you’d like a second set of eyes before you sign — someone who reads these documents daily — that’s exactly what a no-pressure second opinion on your quote is for. Bring the answers you got; I’ll tell you which ones are solid and what to ask next!