The most common hidden costs in a window quote are excluded exterior capping, excluded interior trim, unspecified glass packages, no stated rot repair rate, and a workmanship warranty measured in months rather than years.
A window quote can be technically accurate and still be misleading, because what it leaves out costs as much as what it includes.
These are the specific lines and omissions worth checking before you sign anything.
Exclusions that cost real money
| What is missing | What it costs later | How to spot it |
|---|---|---|
| Exterior aluminum capping | $100 to $250 per opening | Quote says "window only" or does not mention exterior |
| Interior trim reinstall or replace | $75 to $200 per opening | No mention of casing, stool or apron |
| Rot repair rate | Unlimited, discovered mid-job | No stated rate or process for found rot |
| Sill pan | A rotted wall in year five | Flashing never mentioned |
| Disposal and haul-away | $150 to $400 for the job | Not listed under inclusions |
| Glass package specifics | Lower performance than assumed | No U-factor, no low-E, no argon stated |
| Full-frame where needed | Hidden sill damage stays hidden | Every opening quoted identically as insert |
| Warranty registration | Void manufacturer warranty | Nobody says who does it |
Vague language to push back on
- "Premium vinyl" or "top of the line". These mean nothing. Ask for the manufacturer and the specific product line.
- "Energy efficient" without a U-factor. Every window sold makes this claim. The number is what matters.
- "ENERGY STAR certified" without a climate zone. Certification for the Southern zone is optimized for the opposite problem to ours.
- "Lifetime warranty" without saying which component. The frame is usually lifetime, the glass seal is not, and the glass seal is what fails.
- "Includes installation" without defining what installation includes. Does it include capping, trim, disposal, sill pans?
- "Custom sized" as a selling point. Nearly all replacement windows are made to size. It is not a differentiator.
The workmanship warranty tell
Look at the workmanship warranty term and treat it as a proxy for how confident the contractor is in their own installation. A one year workmanship warranty on a product with a twenty year glass warranty tells you the installer expects to be past their obligation before any installation defect surfaces, and flashing failures characteristically show up in year three to five. A contractor offering ten years on labor is making a real commitment about the flashing sequence and the perimeter seal. This single number correlates better with installation quality than almost anything else on the page, and it costs nothing to ask for.
What a good quote looks like
- One line per opening, with the opening identified by room and elevation so you can match it to your house.
- Manufacturer and product line named, not just a brand.
- Whole-window U-factor and air leakage rating per unit type.
- Insert or full frame stated per opening, and varying between them.
- Explicit inclusion of sill pan, perimeter foam, interior trim, exterior capping and disposal.
- A stated rate and process for rot repair if found.
- Product warranty terms by component and workmanship warranty term in years.
- Lead time, deposit amount and payment schedule.
Ranges reflect typical Capital Region projects and are for planning only. Every Sundog quote is written, itemized, and free.
Frequently asked questions
Why is one window quote so much cheaper than another?
Usually because it excludes things. Exterior capping, interior trim, disposal and a lower glass package together account for several hundred dollars per opening, which on a sixteen window house is thousands. Normalize both quotes to the same scope before concluding one is cheaper.
What is exterior capping and do I need it?
Aluminum coil stock bent to wrap the exterior wood trim around the window, so there is no exposed wood left to paint. On a replacement in an older home it is close to essential, because the exterior trim is often the part in worst condition. It runs $100 to $250 per opening and is frequently excluded from cheap quotes.
How should rot repair be quoted?
With a stated rate and a stated process: we stop, we show you, we quote the repair in writing before proceeding. An open-ended "additional charges may apply" is not acceptable, and neither is a contractor who promises there will be no rot before opening anything up.
Is a one year workmanship warranty normal?
It is common and it is short. Flashing and perimeter sealing defects characteristically surface in year three to five, which is conveniently past a one year term. Ten years on workmanship is a meaningfully stronger commitment and it is available from contractors who are confident in their install.
Should the quote name the manufacturer?
Yes, and the specific product line within that manufacturer. Most window manufacturers make several tiers, from builder grade to premium, and the difference between the bottom and top of one brand is larger than the difference between brands at the same tier.
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