Quick Answer: In California, a contractor’s bid is a firm written commitment to complete a defined scope of work at a set price — signing a contract based on a bid locks in that price (subject to change orders for scope changes). An estimate is an approximation of cost that is NOT a firm commitment — the actual cost can vary significantly from the estimate. A “rough estimate,” “ballpark,” or “budgetary number” given before design is complete is an estimate. California law (Business and Professions Code §7159) requires that any work over $500 have a written contract that includes a fixed price or cost-plus schedule — which is functionally a bid. When comparing multiple contractors, always get itemized written bids (not verbal estimates) so you’re comparing apples to apples.
Bid vs. Estimate vs. Quote vs. Proposal — What California Homeowners Need to Know
| Term | What It Means | Is It a Binding Price? |
|---|---|---|
| Bid | Firm written price for a defined scope of work | Yes, when signed as a contract |
| Estimate | Approximated cost — not firm, can vary | No — can change significantly |
| Quote | Usually a firm price for specific materials or labor | Yes (firm within an expiration date) |
| Proposal | A bid + explanation of scope and approach | Yes, when signed as a contract |
| Cost-Plus Contract | You pay actual costs + contractor’s markup % | No fixed price — risk of overruns |
| Fixed-Price Contract | Set total price regardless of contractor’s actual costs | Yes — protects homeowner |
California Contractor Contract Requirements
California Business and Professions Code §7159 requires that contracts over $500 be in writing and include: contractor’s name, address, and CSLB license number; description of the work to be done; materials and equipment to be used; start date and substantial completion date; payment schedule (California caps the initial deposit at 10% or $1,000 — whichever is LESS); a “Notice to Owner” about mechanic’s liens; and a “Right to Cancel” notice for door-to-door sales. Any contract missing these elements can be voided by the homeowner.
Quartz Construction provides detailed written fixed-price contracts for all San Jose remodeling projects. CSLB #1003436 | BBB A+ | Call (650) 749-7436.
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