Plain English:
Project Basis Gate
This article explains the 2024 IMC model-code path. Before project use, confirm the adopted code edition, local amendments, controlling administrative provisions, permit-application date, and current AHJ procedures. The locally adopted requirements control.
Inspections (111.1): Permit work must stay visible and accessible until approved. An approval never legalizes a violation.
Required stages (111.2): Confirm every locally required inspection stage and exception before concealment. Any adopted exception allowing limited operation before inspection must be confirmed with the AHJ; do not assume a universal 48-hour heater rule.
Requests & access (111.2.2-111.2.3): The permit holder schedules inspections and provides safe access. The permit holder - or an authorized representative who can answer technical questions about the installed work - should be present during the inspection. Do not cover or proceed past a stage without approval. Noncompliant portions stay exposed until corrected.
Inspection scheduling: Confirm the AHJ's current request method, notice window, cutoff time, access rules, and required representative. Do not assume a universal 24- or 48-hour notice period.
Third-party help (111.2.4): AHJ can accept inspection and test reports from approved inspection agencies (approved third parties). Confirm the agency is specifically approved by this AHJ before using third-party reports to satisfy an inspection requirement.
Prefabricated assemblies (111.2.5): Evaluation report required; AHJ or an approved agency performs follow-up factory inspections; keep test/inspection records available.
Testing (111.3): Systems must be tested by the permit holder, witnessed by the AHJ; permit holder provides equipment/labor; if something fails, correct and resubmit.
On Plans: Why It Matters in Design & Construction
Inspection sequencing and visibility control protect life safety and your schedule. If you bury or conceal work early, expect demo and delay. Plan prefabricated assemblies with an evaluation report and follow-up inspection path, and treat testing as a witnessed event-tools, personnel, and scripts ready.
Code Path: What to Show
Annotate inspection hold points directly on affected sheets - slab, shaft, and ceiling details.
Include a test matrix: what is tested, who performs it, instruments, pass/fail criteria, and AHJ witness requirement.
Show 'no concealment before inspection' callouts on all sheet details where work will be buried.
Check: Before You Cover
Confirm the required inspection stages: Underground -> Rough-in -> Final (plus any special inspections).
Verify the inspection-request method and notice window directly with the AHJ; jurisdictional procedures control.
For prefabricated assemblies: confirm evaluation report IDs and who performs factory follow-up inspections.
Review Risk:
Don't conceal work before inspection clearance - this is the leading cause of inspection failure.
Don't skip the AHJ witness requirement for required tests - third-party reports must come from an approved agency.
Don't miss the evaluation report requirement for prefabricated assemblies - it must be on file before installation.
Field Tip:
Provide a one-page Inspection Plan in your set and hand it to the GC:
Stages & holds: Underground -> Rough-in -> Final (plus any special inspections).
"No cover" notes: Callouts on sheets showing inspection holds at slabs, shafts, and ceilings.
Prefab path: List evaluation report IDs and who performs factory follow-ups.
Test matrix: What is tested, who performs, instruments, pass/fail criteria, and AHJ witness requirement.
Limited pre-inspection operation: If the adopted code includes an exception, document the local request window, authorization, and no-concealment condition on the affected detail.
Masterbuild QA Lens
Inspection failures are rarely technical - they are sequencing failures. The most common cause is work concealed before the inspection call. Pre-mobilization: put inspection hold points on the drawings, communicate the holds to the GC, and confirm the inspector is scheduled before any phase closes.
Drawing / Submittal Check
Annotate inspection holds directly on the affected sheets - not just on M-001. On slab plans: note underground inspection hold before pour. On mechanical drawings: note rough-in hold before ceiling or wall close. On equipment pads: note equipment inspection hold before utility connection. On underground plans: note pressure test hold before backfill. Holds on the drawings become holds in the field.
Common Review Risk
Three patterns cause most inspection failures: (1) concealing before the call - work closed before the inspector arrives; (2) skipping a stage - underground to final without rough-in sign-off; (3) arriving unprepared for the witness event - pressure test without the right equipment, balancing without the test records, prefab evaluation report not on site. All three are process failures, not code errors.
When To Escalate
Escalate when an AHJ fails a required inspection, demands a retest with criteria not in the approved test matrix, or introduces a new hold point that puts a contractual occupancy milestone at risk.
Rated Assembly Coordination
Inspections cover damper installation, penetration sealing, and access panel placement in rated assemblies. Confirm each inspection phase - rough-in, above-ceiling, final - has a corresponding drawing that shows what the inspector needs to verify.