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North Carolina mechanical, plumbing, fuel gas & energy codes

The North Carolina Building Code Council adopts the NC State Building Code, and the Office of the State Fire Marshal (NCDOI) administers it. The 2018 NC codes (based on the 2015 I-Codes) are still in force because the 2024 NC codes have been delayed several times.

Quick answer: North Carolina currently uses the 2018 NC IMC (2015 base) for mechanical work and the 2018 NC IPC (2015 base) for plumbing (see sources and dates below). A2L status: AHJ approval path under the 2018 NC Mechanical Code

Adopted codes

Mechanical
2018 NC
IMC (2015 base)
Adopted as
2018 North Carolina Mechanical Code
Effective
2019-01-01
Source
NC OSFM – Codes, Current and Past
Last checked
2026-10-29 verified
Notes
2018 NC codes are based on the 2015 I-Codes with NC amendments and are still in force. The 2024 NC codes are adopted but not yet effective.
Plumbing
2018 NC
IPC (2015 base)
Adopted as
2018 North Carolina Plumbing Code
Effective
2019-01-01
Source
NC OSFM – Codes, Current and Past
Last checked
2026-10-29 verified
Notes
2018 NC codes are based on the 2015 I-Codes with NC amendments and are still in force. The 2024 NC codes are adopted but not yet effective.
Fuel Gas
2018 NC
IFGC (2015 base)
Adopted as
2018 North Carolina Fuel Gas Code
Effective
2019-01-01
Source
NC OSFM – Codes, Current and Past
Last checked
2026-10-29 verified
Notes
2018 NC codes are based on the 2015 I-Codes with NC amendments and are still in force. The 2024 NC codes are adopted but not yet effective.
Energy
Residential: 2015 IECC; Commercial: 2015 IECC & ASHRAE 90.1-2013
IECC / ASHRAE 90.1
Adopted as
State energy code (per U.S. DOE BECP)
Effective
Res 2019-01-01; Com 2019-01-01
Source
U.S. DOE Building Energy Codes Program – North Carolina
Last checked
2026-10-29 verified
Notes
2018 NC Energy Conservation Code, with NC amendments.

A2L refrigerants in North Carolina

OSFM guidance (June 4, 2024) says the 2018 NCMC, which is based on the 2015 IMC, sharply restricts A2Ls. It lays out three paths. Paths 1 and 2 are alternative-method approvals under Section 105.2, using ASHRAE 15-2022 or the approved 2024 NCMC Chapter 11. Path 3 is the restrictive prescriptive route. Expect to need code-official approval.

Source: https://www.ncosfm.gov/guidance-papers/a2l-refrigeration-system-installation-under-2018-north-carolina-mechanical-code/open · Last checked 2026-10-29 verified

How A2L rules work nationally

Local amendments & things to watch

  • 2024 NC State Building Code delayed: S.L. 2025-2 §5.12 makes it effective 12 months after the State Fire Marshal certifies that the code is published and the Residential Code Council is fully constituted. verified source
  • The NC licensing board for plumbing, heating and fire sprinkler contractors says the earliest possible effective date is May 1, 2027, and it hasn't been set (update of June 1, 2026). Licensing exams stay on the 2018 codes until then. verified source