Purge & Audit Before Issue: A 5-Minute Model Hygiene Routine

Item 7 of our MEP model setup checklist was “purge and audit before issue” — worth its own routine since it’s the one step that catches problems the rest of the checklist can’t.

The routine

1. Manage → Purge Unused — run it twice, not once. The first pass removes unused families/types/materials; some become unused only after the first purge removes what referenced them. A second pass catches the remainder. Stop after two passes — a third rarely finds anything new and isn’t worth the time.
2. Check the warnings dialog (Manage → Review Warnings) before purging, not after. Purge can silently resolve some warnings by deleting their source, which hides a problem instead of fixing it. Read the warning list first so you know what you’re actually dealing with.
3. Run Audit (File → Save As, check “Audit” in the options, or via the dedicated Audit command) periodically, not just before a milestone. Audit finds and repairs corruption in the file’s internal structure — the kind of silent corruption that eventually causes crashes or “sometimes this element won’t delete” symptoms. Weekly on active models is a reasonable cadence.
4. Time the reopen. After purge + audit, close and reopen the model, timing how long it takes. Target: under 2 minutes on a mid-range workstation for a typical mid-size MEP model. If it’s climbing past that on a model that hasn’t grown much in scope, something (bloated families, excessive in-place elements, view templates gone wild) needs investigating, not just repeated purging.
5. Save a compacted, audited version before handing off or archiving. Enable “Compact File” in the Save As options on the audit pass — this is the version that goes to the coordination team or gets archived as a milestone snapshot, not a quick unaudited save.

Why this order

Warnings before purge (item 2) because purge is destructive to visibility into existing problems — you want to see what’s actually wrong before a cleanup operation potentially hides it. Audit (item 3) is separate from purge: purge removes unused content, audit repairs structural corruption; conflating them means skipping one because you did the other.

Common mistake

Treating a single purge pass as “done” and skipping the second pass — the newly-unused elements the first pass exposes are exactly the ones most likely to be genuinely dead weight (nested families only referenced by other now-deleted families), and they’re the ones a single-pass habit consistently misses.