New Jersey mechanical, plumbing, fuel gas & energy codes
New Jersey's Uniform Construction Code (N.J.A.C. 5:23) adopts model codes by regulation through the DCA Division of Codes and Standards. It's uniform statewide, and local governments can't amend it. The 2024 I-Codes took effect Aug 17, 2026.
Quick answer: New Jersey currently uses the 2024 IMC for mechanical work and the 2024 NSPC (National Standard Plumbing Code) for plumbing (see sources and dates below). A2L status: Allowed: 2024 IMC adopted (Aug 17, 2026)
Adopted codes
Mechanical
2024
IMC
- Adopted as
- Mechanical Subcode, N.J.A.C. 5:23-3.20
- Effective
- 2026-08-17
- Source
- NJ DCA – Current Construction Codes
- Last checked
- 2026-10-29 verified
- Notes
- Adopted at 58 N.J.R. 8(2), effective Aug 17, 2026.
Plumbing
2024
NSPC (National Standard Plumbing Code)
- Adopted as
- Plumbing Subcode, N.J.A.C. 5:23-3.15
- Effective
- 2026-08-17
- Source
- NJ DCA – Current Construction Codes
- Last checked
- 2026-10-29 verified
- Notes
- New Jersey is one of the few states on the National Standard Plumbing Code. A NJ edition is being published.
Fuel Gas
2024
IFGC
- Adopted as
- Fuel Gas Subcode, N.J.A.C. 5:23-3.22
- Effective
- 2026-08-17
- Source
- NJ DCA – Current Construction Codes
- Last checked
- 2026-10-29 verified
Energy
Residential: 2024 IECC (low-rise); Commercial: ASHRAE 90.1-2022
IECC / ASHRAE 90.1
- Adopted as
- Energy Subcode, N.J.A.C. 5:23-3.18
- Effective
- 2026-08-17
- Source
- NJ DCA – Current Construction Codes
- Last checked
- 2026-10-29 verified
- Notes
- DOE BECP also lists 2024 IECC / 90.1-2022, effective 08/17/2026.
A2L refrigerants in New Jersey
New Jersey's adoption of the 2024 IMC brings in the model-code A2L provisions. Projects reviewed under the prior 2021 code during the grace period don't get those provisions. We haven't reviewed New Jersey's Chapter 11 modifications line by line.
Source: https://www.nj.gov/dca/codes/codreg/pdf_rule_adoptions/model_codes_2024_adopt.pdf · Last checked 2026-10-29 verified