Methodology and sources

homerenovationcostcalculator.com separates official statistics from market ranges.

Official inputs are BLS Occupational Employment and Wage Statistics (May 2025), Tax Foundation combined sales-tax rates (July 1, 2026), Census Building Permits Survey (2025), Census Characteristics of New Housing contract prices, NOAA Storm Events (2021–2025), and the ICC adoption chart (April 2026). A blank official cell is left blank. Zero is shown only when the source reports zero, including states with no statewide sales tax.

Market inputs are labeled Estimate (non-official). They were compiled on 2026-10-18 from public cost guides and retailer listings. The typical value is the median of the source midpoints. Low and high are the medians of the source lows and highs. Each row stores the source names, URLs, and page dates. The evidence table behind those medians is loaded with the rest of the data.

Roof formula

The default total is install + tear-off + decking + disposal + permit + optional sales tax.

Roof area is footprint times the pitch factor, or squares times 100. The pitch factor is the square root of 1 plus (rise/12) squared. A square is 100 square feet of roof surface. Waste increases the material quantity used for sales tax. It does not multiply the installed price, because the guide prices already include the contractor’s waste.

Installed price is squares times the installed cost per square times a local labor factor. That factor is 1 minus the labor share, plus the labor share times the roofer wage index. The index is the local OEWS roofer median divided by the U.S. median. Tear-off and decking use the same factor. Disposal is one dumpster rental when at least one layer is removed. Decking sheets are the replaced area divided by 32 square feet, rounded up.

Low and high rerun that formula with the low and high columns of installed price, material price, tear-off, deck sheet, dumpster, and permit. Labor share and the wage index stay at the typical values. Sales tax is off unless you turn it on. Guide prices usually already include the contractor’s materials, so adding tax can double count.

If a material-only price is missing, the tax basis uses installed price times one minus the labor share. It is not treated as zero.

Hours × wage mode is optional. It stays off until you enter install hours, tear-off hours, and a labor burden. No free source publishes those hours. BLS wages are worker pay, not a contractor’s bill rate. That mode does not add a separate markup on top of the wage-and-burden line.

Addition formula

Hard cost is living area times the type’s price per square foot, plus bathroom area times the bathroom rate, plus kitchen area times the kitchen rate. Finish selects the low, typical, or high column. There is no separate finish multiplier in the sources.

The local factor uses the state’s construction wage index (OEWS 47-0000 versus the U.S. median) and the addition labor share, the same way the roof factor works. A second story uses no foundation. Other types start from a slab: crawl, basement, or pier-and-beam add only the difference versus a slab. That slab assumption is editorial. The guides do not state it.

Design fees are the architect percent, plus the engineer percent if that box is on, times hard cost, foundation adjustment, and selected systems. The permit is a separate editable default. Low and high rerun every estimate input, including design percents and the permit. The wage index stays at the value for the selected state.

Census regional new-home prices are context only. They are not addition prices.

Update schedule

Wage, tax, permit, storm, and code tables can be refreshed from published CSV links with the monthly import. Estimate tables change only when the sources are re-read and the medians are rebuilt. This edition of the estimates was checked on 2026-10-18.

Limitations

OEWS excludes the self-employed, and many roofers are self-employed or subcontracted.
Wages are worker pay, not contractor billing rates.
Combined sales tax is a population-weighted average of local rates, not the rate at a specific address. Contractor tax treatment of materials varies by state.
NOAA counts are reports, not unique storms. County counts include only county-coded event types.
Census CHARS dollars per square foot are for new homes, not additions. Regional medians carry relative standard errors of about 4–10%.
ICC adoption data depend on jurisdictions reporting to ICC.
Wind and snow design values are site-specific (ASCE Hazard Tool).
Estimate inputs are non-official market ranges. Sources often disagree. The typical value is the median of the source midpoints.
Guide prices are national. The local adjustment scales only the labor share.
Retail prices came from search snippets of Home Depot listings, not a live store check. Store and ZIP were not specified.
Delaware’s building-permit valuation is withheld on the state page because the published figure looks anomalous.
Some estimate rows rest on a single source. Those rows are marked in the addition table and in the source list.

Source list

Last updated 2026-10-24.