GetWindowCost

Corrections & verification log

Every cost on this site is built from published federal data — wage series, material price indexes, regional adjustments. That claim is worth nothing unless we also publish the times we got a figure wrong. So this page lists them, with what it said, what it says now, and how long the error stood.

Everything in the first section was live on the site. Problems caught in review before publishing are not listed there; calling those “corrections” would flatter us and tell you nothing. Our corrections policy explains the standard, and this page is the record of it being kept.

Think a number is wrong? Email info@getwindowcost.com with the page and, if you price this work for a living, what you actually see in your market. Contractor corrections on regional labour are the most useful mail we get.

Corrections

Published figures that were wrong. Newest first.

  1. September 6, 2026Site-wide — figures the corrected model was published alongsidelive for 2 days before we caught it

    When we re-anchored the cost model on 2026-09-04 we corrected the surfaces we had listed and missed every surface we had not. For two days this site published the corrected figures next to the retired ones: the methodology page still gave the cost formula as "Material + Labor + Supplies" with supplies at 8% of material cost, the rule the second entry below says was wrong; seven pages still quoted $70–$165 of labor per window, derived from the retired glazier wage; four surfaces still billed labor at $47–$65/hour against a real $82.70; the file that tells AI assistants where our numbers come from carried a 50-state price list where 48 of the 50 high figures sat below the national average printed five lines later in the same file; and the homepage listed budget, mid-range and premium bands that did not contain its own "most homeowners pay" figure. Three pages also attributed labor hours to RSMeans for window types we have never been able to verify against RSMeans, and one FAQ answer attributed a stale labor figure to BLS and RSMeans by name.

    Now reads: Every one of those figures is computed from the cost model on each build rather than typed. Where a claim could not be made true from the model or a real source — an unsourced accuracy percentage, a hand-typed page count, a regional labor table no dataset backed — it was deleted rather than replaced with a plausible-looking number. Automated checks now fail the build if a retired figure reappears, if a price in the AI-facing files is not one the model produces, or if the FAQ hand-types a cost.

    Source: BLS Occupational Employment and Wage Statistics; US Census Bureau 2022 Economic Census; DuPont GREAT STUFF product specifications

  2. September 4, 2026Site-wide — installation laborlive for about 5 months before we caught it

    We derived installation labor from the BLS wage for glaziers (SOC 47-2121), an occupation that is predominantly commercial glass work, marked up 1.75x to $48/hour billed. The Census Bureau's 2022 NAICS Index maps residential window installation to Finish Carpentry, not Glass & Glazing, and the real contractor markup measured from the 2022 Economic Census is 2.84x, not 1.75x. Both figures were named in the methodology block on every state and metro page, and in llms.txt, the file that tells AI assistants where our numbers come from.

    Now reads: Labor is derived from carpenters (SOC 47-2031) at a 2.84x markup on the current BLS wage, not a flat $48/hour — against a real residential market of $75–$125/hour.

    Source: US Census Bureau 2022 NAICS Index; US Census Bureau 2022 Economic Census; BLS Occupational Employment and Wage Statistics

  3. September 4, 2026Every calculator estimate — weatherproofinglive for about 6 months before we caught it

    Flashing tape, sill pan, foam and caulk were priced at 8% of the window's material cost instead of by the size of the opening — so a cheap window in a difficult opening carried about $25 of weatherproofing while an expensive window in an easy one carried about $136. Backwards, and it sat inside every published per-window total, including the public window-cost-index dataset.

    Now reads: $11–$19 fixed plus $2–$3 per linear foot of rough-opening perimeter (insert method: $20–$35 flat).

    Source: DuPont GREAT STUFF product specifications; Ace Hardware retail component pricing

  4. September 4, 2026Structured data — Dataset descriptionlive for about 5 months before we caught it

    The JSON-LD Dataset description told search engines and AI assistants the pricing dataset covers 12 window types. WINDOW_TYPES has held 10 since before this figure was ever typed — a false count in machine-readable sourcing metadata that predates this work.

    Now reads: The window-type count is read from WINDOW_TYPES.length rather than typed by hand.

    Source: data/pricing.ts's WINDOW_TYPES array

  5. September 4, 2026Quality tier cards — Good and Better price bandslive for about 6 months before we caught it

    The Good, Better and Best per-window price bands on the quality tier cards were round numbers typed into the site's initial scaffold, with no source, no vintage and no methodology behind them, sitting next to methodology copy that implied every figure traced to the same wage and material data the rest of the site cites. Once labor and weatherproofing were corrected, Good tier's published floor ($350) and Better tier's published floor ($600) both turned out to sit below what the corrected model actually computes for that tier — a homeowner who budgeted at either floor, especially Better, the tier labelled "Most popular," would have underestimated.

    Now reads: Good, Better and Best price bands are computed live from the cost model on every build, not typed by hand — so a future BLS or PPI refresh moves the card instead of leaving it stale.

    Source: BLS Occupational Employment and Wage Statistics; US Census Bureau 2022 Economic Census; FRED producer price index

  6. September 4, 2026Every calculator estimate — Estimated Total Costlive for about 6 months before we caught it

    The "Estimated Total Cost" the calculator has shown since launch never included removing and disposing of the old window — a cost that applies to nearly every replacement job, not an optional extra. The site never disclosed the exclusion, so a total labelled "Total" was, for essentially every visitor, too low.

    Now reads: Removal and disposal is priced as its own line: $25–$60/window below 10 openings, a $300–$500 dumpster at or above that threshold.

    Source: Fairfax County / SWACO published disposal tariffs; EREF landfill survey

  7. July 23, 2026State pages — labour wage

    Where we hold no state-specific glazier wage, the model falls back to the national figure. State pages displayed that fallback without saying it was national, so a reader could take a national average for their own state's rate. The estimate was defensible; presenting it as local was not.

    Now reads: A national fallback wage is labelled as national wherever it is used

    Source: BLS Occupational Employment and Wage Statistics

Verification log

Checks of the data we publish, listed whether or not they found an error. A check that finds nothing is not a non-event — it is the only evidence that the checking happens at all.

  1. July 27, 2026Glazier wages

    Re-ran the wage ingest against the newest Bureau of Labor Statistics occupational employment release.

    Result: Wages refreshed to the May 2025 series. Areas the BLS did not publish in the new release are held at their last published value rather than interpolated, and are marked as such.

  2. July 15, 2026State and utility window rebates

    Verified every rebate programme we list, including whether the federal 25C credit still applies and whether each state programme rebates windows specifically or merely folds them into a whole-home retrofit.

    Result: The federal 25C credit is confirmed expired. Direct per-window rebates survive in only three states; eight programmes bundle windows into broader retrofits and two offer no window benefit at all. Several source links had gone dead and were re-found or flagged. The published asset was reframed around that finding rather than around the more attractive story we expected to tell.

  3. June 7, 2026Material price index

    Refreshed the producer price index series behind material costs.

    Result: Current through April 2026.

Our estimates are a modelled starting point, not a bid. Prices move with local labour and material markets — always get multiple written quotes from licensed contractors for your specific project.