/ Field knowledge · IMC 101
Fuel gas is not in the IMC.
IMC 101: fuel gas is not here — that is the IFGC. 1–2 family homes under three stories can follow IMC or IRC. Confirm with the AHJ before the first M-sheet. Appendices apply only if the jurisdiction adopted them in writing.
Educational 2024 IMC 101. Confirm adopted edition. Distinct from 102 applicability. This is not a permit routing.
- IMC covers design, installation, maintenance, alteration, and inspection of mechanical systems: HVAC, exhaust, ventilation, refrigeration, and related systems.
- 101.1 maintenance is in scope: installed systems must be maintained in safe operating condition. The IMC is not just a construction code.
- Fuel gas piping, gas-fired appliances, and venting follow the IFGC. If fuel gas and HVAC appear on the same permit scope, the gas portion is routed to a separate IFGC permit unless the AHJ accepts a combined set.
- 1–2 family homes under 3 stories can follow IMC or IRC. Confirm the applicable code with the AHJ before the first mechanical drawing is issued.
- Appendices apply only if specifically adopted by ordinance. Do not apply an appendix unless you can cite the jurisdiction’s adoption in writing.
- 101.3 purpose: safety, health, public welfare, and property protection.
M-001 four items from Daily Code Talk: adopted IMC edition, IFGC reference if gas is in scope, IRC vs IMC election for residential, adopted appendices (or “none adopted”).
HVAC and gas on the same M-sheets
The AHJ will hold the mechanical permit until gas scope is explicitly separated and routed. Fix it on M-001, not in response to a comment. A 2-minute “IMC or IRC for this scope?” call can save two weeks of redlines.
Source: DCT 101 · applicability: 102 · official: 104 · permits: 105.
What to send
Whether gas is in scope, whether this is 1–2 family under three stories, and the M-001 code-basis note.
If gas and HVAC are on the same M-sheet
Send M-001. Masterbuild will say whether 101 even has an IMC path for that gas — or this is already IFGC.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval. Confirm the adopted edition. Ez and Voz values below are 2024 IMC 403.3.1.1 education from Daily Code Talk — not a sealed outdoor-air design. This page is not a fee quote.