Our Data Sources
Every cost estimate on CostOnce is built from verified, authoritative data sources. We combine government statistics, industry databases, and current retail pricing to give you accurate numbers.
Occupational Employment and Wage Statistics (OEWS)
Bureau of Labor Statistics
The primary source for labor rates across construction trades. Provides median and mean wages by occupation and geographic area.
Data we use:
- Hourly wage rates for construction trades
- Regional wage variations
- Occupational employment numbers
Regional Price Parities
Bureau of Economic Analysis
Measures price level differences across states and metropolitan areas. Used to calculate regional cost multipliers.
Data we use:
- State-level price indices
- Cost of living adjustments
- Housing cost variations
RSMeans Construction Cost Data
Gordian (RSMeans)
Industry-standard construction cost database used by contractors, architects, and estimators. Provides detailed unit costs for materials and labor.
Data we use:
- Unit costs for construction tasks
- Material quantity estimates
- Labor productivity factors
Craftsman National Construction Estimator
Craftsman Book Company
Annual publication with detailed construction costs, updated with current labor and material prices.
Data we use:
- Residential construction costs
- Contractor markup rates
- Regional adjustment factors
Retail Material Pricing
Home Depot, Lowe's, Menards
Current retail prices for materials, updated monthly by aggregating prices across major home improvement retailers.
Data we use:
- Current material prices
- Product availability
- Price tier comparisons
American Community Survey
U.S. Census Bureau
Annual survey providing housing and economic data. Used for regional adjustments and housing stock analysis.
Data we use:
- Housing characteristics by region
- Median home values
- Construction activity data
Producer Price Index (PPI)
Bureau of Labor Statistics
Tracks price changes for construction materials over time. Used to adjust historical cost data to current prices.
Data we use:
- Material price trends
- Inflation adjustments
- Industry price indices
National Association of Home Builders
NAHB
Industry association providing construction cost studies, builder surveys, and housing market analysis.
Data we use:
- Cost breakdowns by project type
- Builder profit margins
- Market condition reports
Update Schedule
| Data Type | Update Frequency | Last Updated |
|---|---|---|
| Material Prices | Monthly | February 2026 |
| Labor Rates | Quarterly | January 2026 |
| Regional Multipliers | Annually | January 2026 |
| Project Definitions | As needed | February 2026 |
Want to see how we use this data?
Our methodology page explains exactly how we combine these sources to calculate cost estimates.
View Methodology