How to compare contractor bids: a line-by-line method

Start with comparable inputs

Contractors cannot produce comparable proposals from different information. Give each bidder the same drawings, room list, product schedule, known conditions, photographs, and desired timing. Record every clarification you provide after the walkthrough and share material changes with all active bidders.

• Exact areas and work included
• Products already selected
• Items the owner will purchase
• Known damage or prior reports
• Permit and design assumptions
• Desired alternates shown separately

Build a scope matrix

Place contractor names across the top of a table and scope items down the left. Transfer what each proposal actually says; do not fill gaps with assumptions. Mark each line included, excluded, allowance, unit-priced, or unclear.

• Protection, demolition, hauling, and cleanup
• Framing and hidden-condition repairs
• Plumbing, electrical, and mechanical work
• Waterproofing, insulation, and air sealing
• Cabinets, fixtures, finishes, and paint
• Permits, testing, inspections, and closeout

Normalize products and allowances

An allowance is a placeholder, not a final product price. Two proposals with different cabinet, tile, fixture, or appliance allowances are not directly comparable. Ask what quantity, tax, delivery, waste, markup, and installation the allowance includes.

• Write the same target selection beside every bid
• Add likely overages to the comparison total
• Separate material allowance from installation labor
• Confirm whether unused allowance is credited
• Flag products without model numbers or performance requirements

Compare schedule and staffing assumptions

A proposed duration is meaningful only when you understand start conditions, crew availability, inspections, decisions, long-lead materials, and owner-supplied items. Ask who supervises daily work and which major trades are subcontracted.

• Realistic start window rather than an unsupported date
• Milestones and dependencies
• Expected workdays and site hours
• Responsibility for ordering and storage
• Process for delays and schedule updates

Compare payment and change risk

Review current CSLB rules before signing. A proposal should explain progress payments and how extra or changed work becomes a written change order. Do not treat a low base price as complete when foreseeable work is deferred to open-ended extras.

• Payment tied to described progress
• Written change approval before changed work begins
• Labor rates or unit prices where appropriate
• Treatment of credits and deleted work
• Documentation required for concealed discoveries

Score confidence separately from price

Use one score for scope completeness and another for contractor fit. Consider relevant experience, verified license information, references, communication, supervision, warranty process, and the quality of questions asked during estimating. Then compare normalized expected totals—not just the bold number on page one.

Use the free comparison worksheet

Our printable worksheet provides a common scope table, allowance log, questions, and decision record. Complete it before the final contractor interviews so unresolved items can be answered in writing.

Frequently asked questions