How to Evaluate a Construction Bid: Why the Lowest Number Is Rarely the Right Answer

The Price Is Not the Proposal

When commercial owners select contractors on price alone, they are not comparing the same thing. Two proposals for the same project can vary by 20–30% not because one contractor is more efficient, but because one has included more scope, fewer exclusions, and better-defined allowances.

The lowest number is frequently the proposal with the most exclusions, the most aggressive allowances, and the most room to generate change orders during construction. Selecting on price alone is how projects that start on budget end over budget.

What Bid Leveling Is

Bid leveling is the process of normalizing proposals from multiple contractors so that they can be compared on an apples-to-apples basis. It requires reviewing each proposal against the same scope document and identifying where each contractor's bid diverges from that scope.

A leveled bid tabulation shows, for each line item, what each contractor included, excluded, and qualified. Items that one contractor included and another excluded are identified and priced consistently so the total cost comparison reflects the same scope for everyone.

What to Look for in Exclusions

The exclusion log is the most important section of any commercial proposal. Exclusions define what the contractor is not responsible for—and therefore what additional costs may emerge during construction.

• —Scope-based exclusions: Categories of work explicitly removed from the proposal. These need to be priced separately and compared across bidders.
• —Allowance assumptions: Vague allowances that may be far below actual cost. Ask what the allowance is based on and what the contractor's expectation is for final cost.
• —Escalation clauses: Some proposals include material escalation language that allows the contractor to reprice if material costs increase. Understand what this exposure is before signing.
• —Permit and fee assumptions: Some contractors include permit fees in their GMP; others exclude them. Normalize this across proposals.

Qualifications Review

Beyond scope and price, the proposal's qualifications section defines the assumptions under which the contractor developed their number. Changes to those assumptions—a longer schedule, a more complex phasing plan, different access conditions—may affect the final cost even if the scope doesn't change.

Review qualifications carefully and ask each contractor to clarify anything that is ambiguous or that differs from the project requirements.

Selection Criteria Beyond Price

• —Relevant project experience—same building type, same scale, same delivery method
• —Quality and completeness of the proposal itself—is it documented or is it a cover letter with a number?
• —Subcontractor relationships—does the contractor have reliable trade partners or are they going to be scrambling for subs?
• —Project management systems—how do they track costs, schedule, and change orders?
• —References from similar projects—not just any projects

Iron Sparrow Construction is based in North Carolina and takes on commercial and residential construction projects across the United States. Contact our team to discuss your project.