Evidence, dates, and limitations—kept together.
Home Cost Signal keeps government and manufacturer evidence, documented assumptions, and secondary reasonableness checks in distinct production roles.
BLS labor and price indexes, Census geography, manufacturer coverage, and public structural references support specific model inputs or transformations.
National material baselines, accessory rates, disposal allowances, permit fallback, geometry, and other low-confidence factors are explicitly dated and versioned.
Market cost guides test broad reasonableness only. Their prices and formulas never enter the production calculation.
Labor
Official roofer wage data used for state labor adjustment.
US Bureau of Labor Statistics — May 2025 OEWS
May 2025 median hourly wages for Roofers (SOC 47-2181) generate each state labor index relative to the national median. Employee wages are a geographic index only, not contractor billing rates.
Effective 2025-05-01 · Collected 2026-07-17 · United States, national and stateZIP and geography
Census geography used only for a ZIP-derived state approximation.
US Census Bureau — 2020 ZCTA5-to-County Relationship File
Used as a ZIP-derived geographic approximation to select a state. Census ZCTAs are not identical to USPS ZIP Codes and provide no roofing price data.
Effective 2020-04-01 · Collected 2026-07-17 · United States, 50 states and District of ColumbiaRoofing materials, specifications, and price indexes
Manufacturer coverage and system context plus the official asphalt-roofing price index.
US Bureau of Labor Statistics — June 2026 PPI
Commodity series WPU1361, Prepared asphalt and tar roofing and siding products. Used only to update documented asphalt-shingle dollar baselines by an index ratio; the index is never treated as a dollar price or installed cost.
Effective 2026-06-01 · Collected 2026-07-17 · United StatesGAF 2026 Residential Full Line Reference Guide
Used for product coverage and system-component context; it is not a retail-price list.
Effective 2026-01-01 · Collected 2026-07-17 · United StatesGAF Timberline HDZ Installation Instructions
Supports shingle coverage and minimum-slope assumptions.
Effective 2024-07-01 · Collected 2026-07-17 · United StatesGAF Sample Single Family QuickMeasure Report
Supports accessory categories, nominal roll coverage, and the distinction between measured roof geometry and approximate material quantities. The sample quantities are not copied as a house-specific production takeoff.
Effective 2025-04-23 · Collected 2026-07-17 · United StatesDebris, disposal, and structural references
Public context for broad debris-weight bands and construction-and-demolition material categories.
HUD — Structural Design Loads for One- and Two-Family Dwellings
Public residential dead-load references support broad roofing-debris weight bands. They do not provide exact tear-off weights, disposal prices, or contractor rates.
Effective 2001-05-01 · Collected 2026-07-17 · United StatesUS EPA — Construction and Demolition Debris Material-Specific Data
Establishes asphalt shingles, steel, wood, and brick or clay tile as construction-and-demolition debris categories. It does not supply local tipping fees; disposal prices remain documented assumptions.
Effective 2018-01-01 · Collected 2026-07-17 · United StatesSecondary market reasonableness references
Broad validation references only; none of their prices or formulas enters the production calculation.
Angi — Roof Replacement Cost (2026)
Secondary reasonableness check for broad completed-project ranges only. No Angi price, component split, rate, or formula is used by the production calculation.
Effective 2026-03-05 · Collected 2026-07-17 · United StatesAngi — Shingle Roof Cost (2026)
Secondary reasonableness check for broad shingle-project totals only. It is not a production material, labor, permit, or accessory input.
Effective 2026-05-30 · Collected 2026-07-17 · United StatesFixr — Roof Replacement Cost (2026)
Secondary reasonableness check for national installed totals, roof-area scaling, and broad material ordering. Scope varies by comparison, so no Fixr price, rate, split, or formula is a production input.
Effective 2026-01-01 · Collected 2026-07-17 · United StatesHomeGuide — Roof Replacement Cost (2025)
Secondary reasonableness check for broad installed cost-per-area ranges, material ordering, and removal context. Reported scopes are not uniform, and no HomeGuide amount or formula is a production input.
Effective 2025-11-07 · Collected 2026-07-17 · United StatesModernize — Roof Replacement Cost Calculator (2026)
Secondary reasonableness check for a stated 2,000-square-foot US roof and broad asphalt project totals. Inclusions are not sufficiently itemized for production coefficient use.
Effective 2026-03-25 · Collected 2026-07-17 · United StatesProduction source roles
BLS OEWS adjusts installation, tear-off, and selected deck labor by state. BLS PPI series WPU1361 updates only the two documented asphalt roof-covering baselines. HUD residential structural-load tables support broad debris-weight bands. GAF documents roofing-system components, nominal coverage, and the need for measured geometry. EPA provides construction-and-demolition debris context but no local tipping price.
Angi pages are retained only to check whether final project ranges are obviously outside broad market context. Their prices, component splits, labor rates, permit allowances, and formulas are not production inputs. Their registry confidence is low because this limited role does not support a calculator coefficient.
Roof-covering inclusion boundary
The Phase 3B baseline includes only the primary field roof-covering product. Underlayment, leak barrier, starter, ridge cap, drip edge, flashing, fasteners, sealants, delivery, tax, waste, labor, tear-off, and disposal are excluded. Waste is applied once to the product purchase quantity.
The six dollar baselines carry stable documented-assumption IDs. Asphalt coverage and index updates retain GAF and BLS sources; other material categories remain explicit low-confidence assumptions rather than borrowing an unrelated index or competitor price.
Removal, disposal, and accessories
Tear-off dollar rates, national tipping and hauling ranges, accessory unit costs, geometry fallbacks, permit fallback, and deck costs are explicit dated assumptions. The result exposes the selected existing material, layer count, removed squares, estimated debris tons, accessory inclusion, permit source level, and data version.
The additional-cost snapshot is roof-additional-costs-2026-07-v1, effective July 17, 2026. Its generator preserves the curated-input checksum, normalized record checksum, factor checksum, row counts, and validation status.
Calibration references
Fixr, HomeGuide, Modernize, and Angi are recorded as low-confidence secondary references for broad installed totals, roof-area scaling, and material ordering. The calibration record preserves retrieval date, comparison assumptions, stated scope, geographic scope, and limitations. Mixed-scope totals are never treated as equivalent to this calculator's itemized result.
The committed calibration matrix is roof-calibration-2026-07-v1. It validates 25 offline scenarios against safe behavioral ranges and a deterministic output checksum; it makes no live request to a competitor or cost guide.
Permit and local-data boundary
No Census permit count, ZIP code, city name, or state factor is converted into a fee. A confirmed user-entered permit amount replaces the national planning range and is labeled user supplied. Actual fees must be checked with the relevant building department.
Confidence
High confidence describes direct authoritative data, such as an official government release. Medium confidence describes useful public or manufacturer context with known limitations. Low confidence marks broad national dollar assumptions, geometry fallbacks, generic material categories, and secondary market checks. Confidence describes evidence quality, not guaranteed accuracy for a specific roof.