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Public Bidding · 11 min read

Bidding public work: a contractor's checklist for prevailing-wage projects

Davis-Bacon classifications, state prevailing-wage schedules, certified payroll, and the most common scoping errors that sink first-time public bidders.

Public work is different — here’s how

Bidding federal, state, or municipal projects requires more compliance work than private commercial. The labor cost is published by classification, payroll has to be certified weekly, and bid bonds + performance bonds are usually required. First-time public bidders routinely under-estimate by 15-25% because they miss the compliance overhead.

This is the checklist we run on every public-bid estimate at Vortex.

Step 1: Identify which wage regime applies

Federal projects (>$2,000 contract value) trigger Davis-Bacon Act prevailing wages. The wage determination (WD) is published on sam.gov for the project’s county. Apply by trade classification.

Federally-assisted projects (HUD, DOT, EPA-funded work) often trigger Davis-Bacon even if the contracting party is a state or local agency. Read the contract documents carefully for federal funding flags.

State-funded projects in most US states trigger that state’s prevailing wage law:

  • California: Department of Industrial Relations (DIR) wage rates
  • New York: NYSDOL prevailing wage schedules
  • Illinois: IDOL prevailing wage rates
  • Pennsylvania: PA Prevailing Wage Act
  • Massachusetts, New Jersey, Washington, Oregon, Minnesota: each has its own

Right-to-work states (Texas, Florida, North Carolina, etc.) often have no state prevailing-wage requirement, but cities or counties within them may have local prevailing-wage ordinances. Always check the contracting agency’s bid documents.

Step 2: Pull the correct wage determination

Davis-Bacon WDs are published by county and by construction type (Building, Heavy, Highway, Residential). The wrong WD applied = wrong labor cost = wrong bid.

A common error: using a Building WD on a project that includes both vertical building work AND site civil work. The site work needs the Heavy or Highway WD applied to site-trade labor, not the Building WD. We’ve seen this miss alone create 8-12% labor cost errors.

For state schedules, pull the current annual or quarterly schedule from the state Department of Labor website. Make sure you’re using the schedule that’s effective on the bid date or the contract start date depending on the state’s rules.

Step 3: Map each estimating labor classification to a WD classification

Davis-Bacon and state WDs publish rates by classification — “Carpenter”, “Iron Worker (Structural)”, “Operating Engineer Group I”, etc. Your estimating productivity references (NECA, MCAA, RSMeans) use somewhat different classification names.

Build a mapping table for every project:

Estimating classificationWD classificationHourly rateFringeTotal
Electrician (residential)Electrician (Inside Wireman)$48.50$24.20$72.70
HVAC mechanicMechanical Equipment Service Mechanic$42.30$19.40$61.70
Concrete finisherCement Mason$39.80$18.90$58.70

Apply Total = base + fringe to all your labor hours in the estimate. The fringe (health, pension, vacation) is required for compliance even if you don’t actually contribute to multi-employer plans — you can pay it directly to the worker as cash wages.

Step 4: Certified payroll budget

Every week of every Davis-Bacon project, you submit a certified payroll showing every worker’s classification, hours, rate, and fringe payment. This is administrative overhead that costs real money — typically 0.5-1.0% of total contract value when factored honestly.

Budget for:

  • Weekly payroll processing time (1-2 hours per week per project)
  • Payroll software with Davis-Bacon support (or a service like LCPtracker or B2GNow at $200-500/month per project)
  • Audit response time if DOL or the agency selects your project for review

Step 5: Bonds and insurance

Bid bonds (typically 5% of bid value) are required for almost all public bids. The cost is usually paid by the surety carrier upfront and recovered if you win the bid. Budget for the surety relationship — first-time bidders sometimes can’t get bonded.

Performance and payment bonds (each typically 100% of contract value) are required at award. Bond premium runs 1-2% of contract value depending on contractor credit and contract size. Always include this in your bid.

Insurance requirements vary by agency but federal work typically requires:

  • General liability $1M occurrence / $2M aggregate (or higher for larger projects)
  • Auto liability $1M
  • Workers compensation per state statutory
  • Project-specific umbrella

Read the spec section carefully for actual requirements. Don’t carry less than required; don’t bid carrying more than necessary.

Step 6: Buy-American and small business compliance

Federal projects almost always carry Buy American Act requirements — domestically produced iron, steel, manufactured products. Some federally-assisted projects carry stricter Buy America requirements. Specify-and-source decisions during estimating affect whether your bid pricing is even compliant.

Federal projects also carry small business set-aside requirements. If you’re a Small Disadvantaged Business (SDB), 8(a), Women-Owned Small Business (WOSB), HUBZone, or Service-Disabled Veteran-Owned Small Business (SDVOSB), you may have preferential bidding status. If you’re not, certain projects are reserved for those that are.

Step 7: Scope-of-work compliance

Federal and many state contracts require Critical Path Method scheduling. Budget for:

  • Initial baseline schedule preparation
  • Monthly schedule updates
  • Time Impact Analysis (TIA) per AACE recommended practice on any time-affected change order

Federal contracts often require submittal logs, RFI logs, and as-built drawings maintained in specific formats. These are compliance overhead that costs real money.

The 10 most common scoping errors on public-bid estimates

  1. Wrong WD classification or wrong WD county
  2. Forgetting fringe benefits in labor cost
  3. Missing certified payroll administrative overhead
  4. Wrong bond rate or no bond cost at all
  5. Insurance carried below requirement (bid noncompliant) or above (bid uncompetitive)
  6. Missing Buy America compliance on a federally-assisted project
  7. Set-aside misclassification (claiming SDB when you’re not)
  8. Missing schedule and submittal overhead
  9. CPM scheduling cost not budgeted
  10. As-built and closeout documentation cost not budgeted

The bottom line

Public-bid work isn’t harder than private commercial — it’s just more administrative. Get the compliance overhead in your estimate up-front, win bids at margins that account for the actual cost of doing the work, and don’t let an inexperienced estimator give you a bid that wins on paper but loses on certified payroll cost.

Vortex Estimating routinely supports public-bid projects with full Davis-Bacon, state prevailing wage, and federal compliance scope. Send us your spec package and we’ll quote turnaround within 4 business hours.

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