Give every bidder the same property brief
Provide the same roof-area labels, leak history, prior records, access constraints, requested material options and concealed-work questions. Identify which items are mandatory and which are alternates. If a bidder sees a condition that changes the brief, ask for it in writing and distribute any resulting clarification consistently. This does not force identical methods; it makes departures visible. Record the date and version of the brief attached to each estimate so later revisions are not mistaken for the original offer.
Build a line-by-line comparison matrix
Create rows for mobilization, removal, disposal, deck allowances, underlayment, membranes, covering, flashings, penetrations, ventilation, drainage interfaces, protection, cleanup, taxes and closeout. Place each bidder's response in the matching row and quote their exclusions accurately. A blank cell is a question, not an automatic inclusion. Separate quantities, unit prices and allowances from lump sums so council or owner can see where estimates place uncertainty.
Check quantities, units and allowances
Confirm what measurement underlies the roof area and how waste, complex geometry or small sections are treated. For deck replacement, identify whether the unit is a sheet, square foot or another measure and what labour, disposal and material are included. Ask whether an allowance is a budget placeholder, a maximum or reconciled to actual quantities. Comparable arithmetic prevents a seemingly inexpensive proposal from becoming more costly simply because ordinary scope was omitted or hidden-work units were undefined. Illustrative comparison, not a project quote: for the same roof area, material and tear-off scope, A includes two sheathing sheets with material, labour and disposal defined. B says “deck repairs as needed” without a unit or included quantity. Ask B to define that row and both bidders how additional quantities are priced and approved before comparing totals.
Compare concealed-work processes, not guesses
No bidder can fully price unseen deck or transition conditions without an agreed assumption or investigation. Compare how each proposal will identify, photograph, measure, approve and price a discovery. Ask who has authority to stop work or authorize the change and how weather protection is maintained while a decision is pending. Treat structural or hazardous-material issues as separate qualified-review questions rather than forcing them into an ordinary sheathing allowance.
Evaluate schedule and property protection
Compare proposed start windows, estimated sequence, crew access, material storage, occupied-area coordination and weather response. Dates should be understood as written commitments or estimates according to the actual contract, not promises inferred from a sales conversation. Ask how entrances, vehicles, landscaping and neighbouring property will be protected and how daily cleanup is handled. WorkSafeBC's material can inform safety awareness, while work methods and regulatory compliance remain the contractor's responsibility.
Read change, payment and warranty terms
Review deposit, progress billing, holdback or other payment terms with appropriate advice for the actual contract. Require a written change process that identifies scope, cost, schedule impact and approval. Ask for the actual product and workmanship documents, including registration steps, exclusions and owner obligations. Do not award points for a warranty headline without reading the supplied terms. Ensure the contracting party, estimate validity and taxes are identified so the commercial comparison reflects the documents on offer.
Score completeness before price
Resolve material gaps and obtain revised written proposals where necessary. Then score scope completeness, evidence process, exclusions, communication, schedule, closeout and price using criteria chosen before the final decision. Record reference checks or qualifications only when they have been genuinely verified; do not invent credentials or local experience. The final note should explain why the selected proposal offers the best fit for the defined scope, not simply state that it had the lowest or highest total.