Tennessee mechanical, plumbing, fuel gas & energy codes
Tennessee's State Fire Marshal's Office (Department of Commerce & Insurance) adopts statewide building, mechanical, plumbing, fuel gas and energy codes. Exempt cities and counties with approved inspection programs can adopt their own codes, as long as they're at least as strict and approved by OSFM.
Quick answer: Tennessee currently uses the 2021 IMC for mechanical work and the 2021 IPC for plumbing (see sources and dates below). A2L status: Allowed by state law (Public Chapter 771 of 2022)
Adopted codes
Mechanical
2021
IMC
- Adopted as
- Rule 0780-02-02 (State Fire Marshal adopted codes)
- Effective
- 2025-04-17
- Source
- TN SFMO – Currently Adopted Codes
- Last checked
- 2026-10-29 verified
Plumbing
2021
IPC
- Adopted as
- Rule 0780-02-02 (State Fire Marshal adopted codes)
- Effective
- 2025-04-17
- Source
- TN SFMO – Currently Adopted Codes
- Last checked
- 2026-10-29 verified
Fuel Gas
2021
IFGC
- Adopted as
- Rule 0780-02-02 (State Fire Marshal adopted codes)
- Effective
- 2025-04-17
- Source
- TN SFMO – Currently Adopted Codes
- Last checked
- 2026-10-29 verified
Energy
Residential: 2018 IECC; Commercial: 2021 IECC & ASHRAE 90.1-2019
IECC / ASHRAE 90.1
- Adopted as
- State energy code (per U.S. DOE BECP)
- Effective
- Res 2020-07-16; Com 2025-04-17
- Source
- U.S. DOE Building Energy Codes Program – Tennessee
- Last checked
- 2026-10-29 verified
- Notes
- Residential (one- and two-family and townhomes) uses the 2018 IECC with amendments.
A2L refrigerants in Tennessee
Public Chapter 771 (SB 1801, effective Apr 8, 2022) says state and local building standards can't prohibit or limit equipment that uses a refrigerant listed under federal safety standards, if it's installed under the federal use conditions.
Source: https://wapp.capitol.tn.gov/apps/BillInfo/Default?BillNumber=SB1801&ga=112 · Last checked 2026-10-29 verified