How to Compare Contractor Proposals

A comparison becomes fair only when contractors use the same drawings, quantities, specifications, site conditions, taxes, exclusions, schedule and responsibility basis.

How to assess this decision in practice

Create a normalisation table before ranking prices. Move each proposal onto the same scope, quantity, specification, provisional-sum, tax, exclusion, schedule and responsibility basis. A total-price difference becomes meaningful only after those bases align.

A low price may reflect efficiency, but it may also result from missing items, low quantities, alternatives, an unrealistic schedule or risk shifted to the owner. Clarifications should be recorded and incorporated into contract documents rather than remaining conversational.

What to check

Use this list as a starting point. The depth of review should still match the project stage, decision value, documents and risks.

1. Use the same clarification list and proposal template.
2. Separate direct prices, provisional sums, allowances, taxes, contingency and owner works.
3. Flag blank items, quantity differences, alternatives and exclusions.
4. Compare project organisation, method, schedule, labour, procurement and quality controls.
5. Review payment structure, retention, variations, warranty, defects and document close-out.

Turn the review into a recorded decision

1. Set the baseline: documents, conditions, dates, parties, reviewed areas and access limitations.
2. Separate observed facts, third-party statements, assumptions, risks and professional opinions.
3. For each issue, define the required decision, authority, action owner, target and closure evidence.
4. Retain document versions and approvals so later changes can be compared against the correct basis.

Questions before deciding

A useful answer should be traceable to documents, site conditions, a responsible party or a clearly stated assumption boundary.

• Does the total cover the same scope?
• Which assumptions have the largest price impact?
• How are variations valued and approved?

How to document the outcome

Record information sources, review dates, documents read, people interviewed, inaccessible conditions, key findings, decisions, owners and follow-up deadlines. Separate facts, third-party statements, assumptions and recommendations.

For legal, structural, geotechnical, tax, permitting, land, design or specialist-testing decisions, use appropriately authorised and qualified professionals.