What Makes Up a Contractor's Price
A professional contractor's price covers four components — and understanding each one helps you evaluate whether a bid is fair:
| Component | Typical % of Total | What It Covers |
|---|---|---|
| Labor | 40–60% | Wages, payroll taxes, workers' comp insurance, crew benefits |
| Materials | 25–40% | Product cost + markup (15–30%) for purchasing risk, delivery, waste |
| Overhead | 10–20% | Office, fleet, insurance (GL + WC), estimating, admin, software |
| Profit | 10–20% | Return on business risk; funds equipment, working capital, growth |
A $15,000 roof bid might contain: $6,500 labor, $5,000 materials (including $1,000 markup), $1,500 overhead allocation, and $2,000 profit. A $12,000 bid from a competitor might have the same or similar labor and material cost — but lower overhead (smaller operation) or lower profit target. Neither is automatically wrong or right.
Labor Cost Drivers
Labor is the most market-variable component — and the reason the same project costs 30–50% more in San Francisco than Houston. Labor cost to a contractor includes:
- Wages: Skilled tradespeople earn $25–$75/hour depending on trade and market
- Payroll taxes: Social Security (6.2%), Medicare (1.45%), FUTA/SUTA — adds 8–12% above wages
- Workers' compensation insurance: Rates vary by trade risk — roofing WC can be 15–25% of wages in some states; general carpentry 5–10%. This is why roofing always seems expensive relative to simpler trades.
- General liability insurance: $1–3% of revenue for most contractors; more for high-risk trades
- Subcontractor markup: When the primary contractor subs out specialty work, they typically mark up the sub's price 10–25% to cover coordination, management, and their own liability exposure
Material Markup
Contractors typically mark up materials 15–30%. This is legitimate overhead recovery for: purchasing and managing delivery, maintaining relationships with suppliers, carrying risk on damaged or defective materials, and absorbing the cost of waste/cutoffs. On a $5,000 material purchase, a 20% markup ($1,000) is reasonable overhead compensation.
On large projects, you may be able to negotiate "cost-plus" pricing where you see actual material invoices. This is more common in custom work and large-scope remodeling than in standard trade work (roofing, HVAC, concrete). Most contractors on smaller projects use bundled pricing because unbundling creates more administrative work than either party benefits from.
Why Bids Vary by 20–40% for the Same Project
Legitimate reasons for bid variation:
- Different overhead structures: A solo owner-operator has $2,000/month in overhead; a regional contractor has $50,000/month. They need to recover different amounts from each project.
- Different material specifications: Two roofers may both say "30-year shingles" — one is quoting Owens Corning Duration (premium), one is quoting a value-tier product. Always confirm the specific brand and product line.
- Different scope interpretations: One contractor includes disposal, one doesn't. One includes permit, one assumes you'll pull your own. One includes replacing deteriorated decking, one excludes it until they get up there.
- Current workload: A contractor with a full backlog bids high; one needing work bids tight. This is rational market behavior.
Illegitimate reasons for low bids:
- Missing scope: The intentional lowball — excludes items to look cheapest, then adds change orders
- Uninsured/underinsured labor: Skipping workers' comp cuts labor cost 15–25%, but shifts the accident liability to your homeowner's insurance (and your legal exposure)
- Substandard materials: Brand substitutions that look equivalent but aren't (common in HVAC, windows, roofing underlayments)
How to Read an Itemized Bid
Always request an itemized bid, not a lump sum. A professional bid should include:
- Specific material brands, models, and quantities
- Labor scope with clear inclusions and exclusions
- Permit as a line item (if your project requires one)
- Disposal/dumpster as a line item
- Warranty terms (labor warranty separate from manufacturer material warranty)
- Payment schedule tied to project milestones, not arbitrary dates
Compare bids at the line-item level, not the total. A bid that's $1,500 lower than the others often has $1,500 less scope buried in the fine print. The cheapest total is meaningless if the scope differs.
Red Flags in Contractor Bids
- Lump sum only, won't itemize: A legitimate contractor can itemize their bid. Refusal to do so is a red flag.
- Large upfront deposit demand: 10–25% upfront is normal for materials. Asking for 50%+ before work starts is unusual and risky — use a credit card if possible for fraud protection.
- No permit line item for permitted work: If your project requires a permit (most structural, electrical, HVAC, and roofing work does) and the bid doesn't include it, either the contractor is planning to skip the permit or they haven't disclosed the cost. Both are problems.
- No insurance documentation: Ask for a Certificate of Insurance before signing. You want to see active General Liability ($1M per occurrence minimum) and Workers' Compensation coverage. If they can't provide it, they don't have it.
- Price guaranteed to match insurance: Contractors who will "do whatever insurance pays" may be defrauding your insurer or planning to use inferior materials/labor to fit a constrained budget.
- Change order language is vague: Good contracts specify how changes are priced (unit rates or time-and-material with caps). Vague change order language enables abuse.
How to Negotiate Effectively
- Scope reduction: Ask what you can remove from scope to hit your budget — often the contractor can propose alternatives (e.g., standard rather than premium finish, deferred phases) that protect value
- Bundling: If you have multiple projects, give them all to one contractor — the reduced mobilization cost and scheduling efficiency often produces 8–15% discounts
- Timing: Projects scheduled in the contractor's slow season (winter for exterior work, summer for HVAC in cold climates) often bid lower because contractor utilization is lower
- Payment terms: Offering quicker payment or credit card processing (contractors lose 2.5–3%) is sometimes used as a negotiating chip
- Don't use the lowest bid as a hammer: Telling your preferred contractor to match the lowest bid creates a race to the bottom — it signals you haven't thought carefully about why bids differ and encourages scope cutting rather than honest pricing
Frequently Asked Questions
Why do contractor bids vary so much for the same project?
Legitimate variation comes from different overhead structures, material specifications, and scope interpretations. Illegitimate variation comes from missing scope items, uninsured labor, and intentional lowballing with expectation of change orders. Always compare bids line-by-line, not just the total price — a $1,500 gap often hides $1,500 of missing scope.
Should I hire the cheapest contractor?
Rarely. The lowest bid typically signals missing scope, uninsured labor, or a contractor with cash flow problems. Get 3 itemized bids, compare scope line-by-line, verify insurance, and choose based on value. The median bid is usually the most reliable data point — it represents what the market actually charges for the full, properly-insured scope.
How much upfront deposit is reasonable?
10–25% upfront is standard for materials on most projects. Never pay more than 33% before work begins. Larger projects often use milestone-based payment schedules (e.g., 25% at start, 25% at rough-in, 40% at substantial completion, 10% at final). Never pay in full before completion — retaining 10% through final inspection protects you against incomplete punch-list items.
Related Cost Guides
📋 Always Itemize
Never accept a lump-sum bid for a significant project. Itemized bids let you compare scope line-by-line, identify what competitors are omitting, and negotiate specific components. A contractor who refuses to itemize is hiding something.