How our cost ranges are built

Estimator version

Current: est-v1.0 (first release 2026-10-28). Price basis captured 2026-10-04 from a proprietary trade price book (the "Flowwork price book"), which reflects what established service companies charge for defined jobs. All figures are USD.

Evidence classes — kept separate, never averaged

1. Flow Decoded modeled estimate. Derived from the price book plus documented assumptions. This is our only supported class today.

2. Advertised examples. A company's dated public offer with its own terms. We have not published any yet; when we do, each will name the company and date.

3. Observed market range. Only from a real sample of comparable completed jobs, with sample size, period, and geography shown. We have no such sample, so you will not see this label from us.

The modeled range rule (est-v1.0)

Where the book supports a single price for a defined job and we lack a defensible variability model, we present price × 0.80 to price × 1.20, explicitly labeled a modeled band. That ±20% band is a documented planning assumption — not a statistical confidence interval, not a survey of the market, and not a percentile. Real quotes can legitimately fall outside it when access, equipment, or code conditions differ from the standard scenario.

What the estimates are not

They are not binding quotes, not offers by any listed company, not a "fair price" ruling, and not the internal cost a contractor pays. A homeowner should expect a licensed contractor's actual quote to reflect that contractor's scope, trip, and business — the range helps you sanity-check it, not replace it.

Geography

Supported basis: Triangle, North Carolina (Wake, Johnston, Durham county area). These numbers are not national data. If you're elsewhere, treat them as nonlocal reference only.

Taxes, permits, fees

No sales tax is applied because the taxable basis for mixed labor/materials jobs in NC is not established in our data. Permits are excluded unless a scenario says otherwise. Service-call and diagnostic fees are shown as separate scenarios, not silently baked into repair prices.

Changes and corrections

When the price book or rules change, the estimator version increments and changed scenarios are listed on /changes. Report problems to [email protected] — corrections get reviewed and preserved in a visible history.