Estimating methodology
Every estimate should be understandable, reproducible and honest about uncertainty.
Calculation structure
Project size is multiplied by a baseline material rate and selected material and condition factors. Materials and professional labor are localized separately. Permit, disposal and contingency allowances are shown as separate lines.
| Component | Purpose |
|---|---|
| Material baseline | Editorial unit-cost assumption that requires supplier validation. |
| Material geography | 2024 BEA Goods Regional Price Parity for the state containing the ZIP geography. |
| Labor geography | 2024 BEA Services: Other Regional Price Parity used as a public-data fallback until trade-specific licensed wage data is available. |
| Waste | Accounts for cuts, breakage and ordering tolerance. |
| Planning range | Communicates uncertainty rather than false precision. |
Geographic sources
ZIP validation uses the 2025 U.S. Census ZCTA Gazetteer. Each ZCTA is assigned to the county containing its largest land share using the Census 2020 ZCTA-to-county relationship file; the county FIPS supplies the state. ZCTAs are Census statistical geographies and are not identical to every USPS delivery ZIP.
Personal calibration
A visitor may store a bounded adjustment derived from a comparable written local quote. It applies only to that project and three-digit ZIP prefix on that device. This is not pooled into the public model.
Limitations
Baseline rates remain editorial planning assumptions, not live supplier or contractor quotes. BEA price parities cover broad goods and services rather than individual construction trades. Actual costs vary with availability, taxes, code requirements, engineering, access, hidden conditions, contractor demand and scope. Licensed unit-cost data, current supplier feeds and professional review are still required before claiming quote-level accuracy.