Published September 1, 2026Editorially reviewed
Answer first
TL;DR
Review the source set, scope, systems, counts, lengths, fittings, equipment, supports, revisions, pricing inputs, exclusions, and exported estimate. Sample every major quantity back to its drawing location. A named estimator should approve the final takeoff before pricing or bid submission.
What should be checked before quantities?
Confirm that the input set is complete and current.
- Correct drawing issue and sheet list.
- Plumbing plans, risers, schedules, legends, and specifications included.
- Addenda and bulletins identified.
- Scope boundaries and alternates recorded.
- Units, scale, and measurement rules confirmed.
- Bid due date and output format recorded.
Which quantities need review?
Review each quantity class separately because the failure patterns differ.
| Quantity class | QA check |
|---|---|
| Fixtures | Count, type, schedule match, and carrier or accessory needs |
| Pipe | System, size, material, length, vertical distribution, and allowance rules |
| Fittings and valves | Type, size, system, and assembly logic |
| Equipment | Schedule match, capacity, accessories, and connection scope |
| Supports and penetrations | Hangers, sleeves, firestop, and specification requirements |
| Specialty systems | Gas, acid waste, storm, condensate, treatment, or project-specific scope |
Beam AI and Bobyard publish plumbing quantity categories that cover many of these checks. Their lists are useful prompts, but the contract documents and contractor scope remain controlling.
How should revisions be checked?
Compare the revised set to the exact prior issue.
Verify added, removed, and changed quantities by sheet and system. Confirm that fixture schedules, specifications, and keyed notes changed with the plan. Beam AI documents an addendum variance workflow, but the estimator should still confirm the affected scope.
What should be checked before pricing?
Do not price an unaccepted takeoff.
Confirm material catalog matches, labor units, productivity factors, waste, taxes, freight, equipment, subcontractor costs, overtime, location assumptions, overhead, markup, and alternates. Keep assumptions and exclusions visible in the estimate.
Who signs off?
Assign one accountable estimator.
The record should show the reviewer, date, drawing issue, exceptions, corrections, and final approval. Ruh AI documents estimator review and sign-off, while Beam AI offers a human-QA workflow. When software does not provide that layer, the contractor must supply it.
Source ledger
Which primary sources were reviewed?
Provider capabilities and prices are attributed to official pages. Company-published material describes what the provider documents and does not establish independent performance.
Buyer questions
Frequently asked questions
Should every quantity be traced to a drawing?
At minimum, sampled and high-risk quantities should retain a clear source reference. Full traceability is preferable when the software supports it.
What is the most common QA mistake?
Accepting a plausible total without checking system assignment, scope completeness, and addenda. Totals alone do not show whether the right work was counted.
Does this checklist replace an estimator?
No. It organizes the review. The estimator still interprets the documents and approves the commercial result.
Should the original AI output be saved?
Yes. Preserve the initial output, corrections, final version, and source set so the team can evaluate recurring errors.
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