How to Review a Drawing Revision Before Updating a Quote

When a drawing revision arrives mid-quote, the natural instinct is to compare the new set with the old one, adjust a few quantities, and keep pricing. That works for minor changes, but it creates real risk when the revision affects scope boundaries, material specifications, connection details, finishes, or commercial terms that the estimator has already built into the quote.

A structured drawing revision review starts by confirming what changed, not guessing. ISO 19650 guidance treats revision and status as metadata, not optional descriptions, and makes the point that information should be reviewed against requirements before it is accepted for use. For estimating teams, that means revision control is a formal step between file receipt and pricing adjustment, not a quick visual check.

Start with a revision comparison using actual tools rather than flipping between PDF tabs. Acrobat Compare Files generates a report of differences between two versions. Bluebeam offers Compare Documents for markup-based comparison and Overlay Pages for colour-stacked visual comparison, including batch variants and alignment methods where drawings are not perfectly matched. For scanned drawings, Bluebeam's Compare Documents works better than vector overlay methods.

Compare these specific elements: title-block revision letter or number, issue date, sheet count, material call-outs and specifications, dimensions and tolerances, connection details and finishes, notes and general clauses, and the drawing list or register if included. A connection detail change from bolted to welded, or a plate thickness change from 10 mm to 12 mm, can alter pricing scope even when the overall arrangement looks the same.

The Australian Steel Institute notes that tender-stage documentation should contain enough information to price every structural steel member with indicative connection detail. When a revision arrives, check whether the updated documentation still meets that standard. If the revision introduces new ambiguity or removes previously clear information, that is a review point, not a pricing adjustment.

Not every revision requires a full requote. Categorise the impact before pricing changes. Minor administrative changes such as a corrected title-block date or non-material note clarification are low risk — update the file register and proceed with the existing quote, noting the revision.

Scope-affecting changes such as a revised member size, added connection detail, changed material grade, or updated finish specification are medium to high risk. Compare quantities, reassess labour assumptions, and update the estimate before proceeding. If the change affects more than one discipline or subcontract scope, notify the relevant parties before finalising price adjustments.

Commercial changes such as a revised delivery programme, changed tender conditions, added alternates, or a scope reduction that removes previously quoted work are high risk. Pause pricing and confirm the commercial basis with the client or internal lead before making any adjustments. A revision that changes the tender validity period or delivery terms may need a new quote basis entirely.

Conflicting or incomplete revisions where a new issue sheet contradicts an unchanged sheet from the previous set are also high risk. Log the conflict and request clarification before adjusting pricing. Do not assume the later revision dominates across all disciplines — coordination issues between architectural and structural sheets are a known problem in fabrication quoting.

A simple revision register for quote tracking captures: project or RFQ code, sheet or document number, old revision, new revision, date received, scope impact assessment (minor, scope change, commercial change, or conflicting), quantity impact notes, reviewer initials, review date, and whether the quote was updated or requoted. This follows the same evidence-tracking discipline described in the <a href="/blog/organise-rfq-files-before-estimating">RFQ file organisation guide</a>, now applied specifically to mid-quote changes.

The register serves two purposes. It documents what the estimator reviewed and decided, which matters when a post-award dispute arises about which revision was priced. And it creates a feedback loop for future quotes: teams can see which revision types most often trigger material commercial changes and adjust their intake triage accordingly.

When the revision confirms the previous pricing scope with no material change, proceed without adjustment and update the file register. When the revision adds detail that confirms assumptions already stated in the quote, proceed without adjustment but update the assumptions register to reflect the confirmed scope.

When the revision changes quantities, material specifications, or connection details within the existing scope boundaries, update the estimate with revised quantities and review labour and material pricing before finalising. When the revision changes scope boundaries, commercial terms, or delivery conditions, pause pricing, escalate to project lead or client, and confirm whether a revised quote basis is needed.

When the revision conflicts with other issued documents or is incomplete, pause pricing and request clarification from the issuer. Do not assume the drafting inconsistency is harmless. When multiple revisions arrive in sequence without clear consolidation, treat the latest package as provisional until the governing revision set is confirmed, using the same intake control principles from the <a href="/blog/rfq-intake-checklist-fabrication-estimating">RFQ intake checklist</a>.

How should I compare two revisions of the same drawing? Use actual comparison tools rather than visual flipping. Acrobat Compare Files generates a difference report. Bluebeam Compare Documents highlights markups and Overlay Pages colour-stacks changes, including batch comparison where multiple drawings are involved.

When should I requote rather than adjust? When the revision changes scope boundaries, commercial terms, material specifications, or delivery conditions. Minor administrative changes do not need a requote, but any change that alters the pricing basis does.

What if the revision arrives after I have sent the quote? Log the revision and assess materiality. If the change affects the quoted scope or price, notify the client and issue a revised quote or addendum. If the change is minor, log it and confirm acceptance with the client.

Should I keep the old revision after a new one arrives? Yes. Move superseded revisions into a clearly labelled archive folder rather than deleting them. The decision trail matters for post-award review and dispute prevention.

How do I handle a revision that only affects some sheets in a multi-sheet set? Isolate the affected sheets, compare the specific changes, assess whether the change propagates to connected sheets or assemblies, and update only the affected scope items. Do not requote the entire package unless the change cascades.

What if the client says just use the latest revision without specifying what changed? Treat this as a clarification trigger. Request a transmittal or revision note that identifies the specific changes, or run a comparison yourself and document what you found before pricing.