We're launching IMC Chapter 3, Section 301 as a concise three-part series. This is the section where plan-review friction shows up-listings, labeling, plastics, and wind/flood/seismic basics.
We'll cover 301 in three focused parts:
Part 1: 301.1-301.5 - Scope, Energy Utilization, Identification, Plastics, Third-Party Proof
Part 2: 301.6-301.13 - Fuel Gas, Listed/Labeled, Label Information, Electrical, Plumbing Connections, Fuel Types, Vibration Isolation
Part 3: 301.14-301.18 - Repair, Wind Resistance, Flood Hazard, Rodent proofing, Seismic Resistance
Start with Part 1 (301.1-301.5) linked above.
Code Path: IMC Section 301.1 (Scope) -> Section 301.3 (Equipment Identification) -> Section 301.7 (Listed/Labeled) -> Section 301.9 (Label Information) -> Section 301.15-301.18 (Wind, Flood, Seismic). Reference IFGC for fuel gas, NFPA 70 for electrical, IBC for structural.
Section 301.1 applies to all mechanical systems covered by the IMC - not just HVAC.
Section 301.7 requires all equipment to be listed and labeled for its application and installed per the manufacturer's instructions.
Sections 301.15-301.18: Structural compliance (wind, flood, seismic) is required regardless of whether the AHJ flags it proactively.
Check: Before You Submit
Confirm M-001 states the applicable code edition and scope (new, alteration, or replacement) before any other notes.
Verify every piece of equipment on the schedule has a manufacturer, model, and listing reference shown.
Confirm mounting heights, clearances, and installation details are shown for all equipment in garages or at-grade installations.
Review Risk:
A listed product installed outside its listing conditions or without the required manufacturer's instructions on site.
Equipment identification (301.3) failures - missing nameplates or tag references on drawings - trigger field inspection holds.
Missing flood elevation callouts on equipment in flood hazard areas generates AHJ corrections during permit review.
Masterbuild QA Lens
A listed appliance installed wrong is still a redline. Confirm every piece of equipment in the schedule has a matching listing, is installed per the manufacturer instructions and the applicable code section, and that the permit set shows it. Listing plus compliance equals approval - only one of those two is not enough.
Drawing / Submittal Check
M-001 must state the adopted edition of the IMC, the scope of the project (new, alteration, or addition), the occupancy classification, and any adopted local amendments to IMC Ch3. If the project involves regulated occupancies (hazardous, institutional, assembly), call out the applicable Ch3 section on M-001. Reviewers who cannot identify the project scope from M-001 will ask before opening the first mechanical sheet.
Common Review Risk
The permit application, cover-sheet scope, equipment schedules, and field work describe different limits. Reconcile the approved scope before procurement or installation.
When To Escalate
Escalate when the permit scope does not match the drawings or the field team proposes work beyond the approved documents. A material mismatch can require revised documents, AHJ direction, or enforcement action.