This page lists every source used to build and maintain our cost estimates, what each one contributes, and where each one is weak. We would rather state the limitation than imply a precision we do not have.
| Source | Used for | Limitation |
|---|---|---|
| Manufacturer published pricing Major US vinyl and fiberglass window manufacturers |
Material rate per square foot; relative pricing between product lines | Published pricing is list price, not contractor cost. Contractors buy below list, so material figures trend high against real invoices. |
| Installer rate surveys Regional and national remodeling cost surveys |
Labor per opening; regional labor multipliers | Survey responses skew toward larger firms. Small-crew pricing is often lower and under-represented. |
| US Bureau of Labor Statistics Occupational Employment and Wage Statistics; Producer Price Index |
Regional wage levels for construction trades; material price trend direction | Wage data is occupation-level, not window-install-specific. Used as a directional check on the regional index, not as the index itself. |
| US Census Bureau American Community Survey; building permits survey |
Housing stock age (pre-1978 lead-safe relevance); regional construction volume | Aggregated to county or metro level; does not reflect neighborhood variation. |
| Building permit records Municipal open-data permit portals |
Observed permit volume by window work type; typical project valuation where reported | Valuation fields are populated inconsistently between jurisdictions and are frequently absent for residential replacement work. We do not use permit valuation as a price source. |
| Building code text International Residential Code; state and local amendments |
Egress geometry requirements; tempered glass locations; permit triggers | Model code is a floor, not the local rule. Local amendments override and vary widely. We flag this on every code claim. |
| ENERGY STAR and NFRC Program criteria; certified product ratings |
U-factor and SHGC thresholds by climate zone; whole-unit performance basis | Program criteria and federal incentive rules change between program years. Eligibility must be confirmed against current program documentation. |
| EPA lead-safe rules Renovation, Repair and Painting Rule |
Applicability threshold for pre-1978 housing; cost adders for lead-safe practices | Applicability depends on the specific property and on whether the firm is certified. Our adder is a range, not a quote. |
Material rates are anchored to manufacturer pricing and adjusted downward using installer rate surveys to approximate contractor cost. Labor rates are anchored to survey data and cross-checked against BLS wage levels for directional consistency. The regional multiplier is derived from labor survey data and validated against BLS wage differentials.
Where two sources disagree materially, we report the wider range and state the disagreement rather than picking the more attractive number.
| Date | Change |
|---|---|
| 2026-11-11 | Initial publication of methodology v1. Material rates, labor rates, and 20-state index established. Review cycle set to monthly. |
If you have invoices, manufacturer cost sheets, or permit records that contradict a published figure, send them to [email protected]. Evidence-based corrections are published with a dated note. See Contact.