Tennessee enforces the 2021 IECC commercial, with exceptions

Record of adoption

In force since

Apr 17, 2025

Legal citation

Tenn. Comp. R. & Regs. 0780-02-02-.01(1)

Adopted by

Tennessee Department of Commerce and Insurance, State Fire Marshal’s Office

Second reading

Agreed Oct 19, 2026

Applies

Statewide, with exceptions

DOE lists ASHRAE 90.1-2019 as the alternative path. The rule removes C405.11, C405.12 and C408 commissioning and keeps the 2006 IECC for certain F-1, F-2, S-1 and S-2 occupancies; Public Chapter 149 (2025) also exempts the 2021 roof reflectance/emittance requirements from July 1, 2025.

Exceptions

• Exempt jurisdictions (municipalities certified to enforce their own building and fire codes, which must be kept within 7 years of the latest edition and approved/audited by the State Fire Marshal) are not subject to the statewide codes except for state buildings, educational occupancies and state-licensed occupancies.

How Tennessee adopts the IECC commercial

• Agency rule
• A recent law changed the process

The State Fire Marshal’s Office (Dept. of Commerce and Insurance) adopts model-code editions by rulemaking under T.C.A. 68-120-101 (chapters 0780-02-01 NEC, 0780-02-02 building/fire/energy, 0780-02-23 residential), filing with the Secretary of State. No legislative approval step was found; the General Assembly constrains content by statute (for example no mandatory sprinklers in one- and two-family dwellings, 2/3 local vote for local sprinkler mandates) and in 2025 Public Chapter 149 carved a roof-reflectance requirement out of the 2021 IECC.

Cycle. Irregular, roughly every 4 to 8 years and not every code at once: NEC 2017 since 2018; residential IRC/IECC 2018 since 2020; IBC/IFC/commercial IECC 2021 since 2025.

Laws, rulings, and other actions

1. Apr 3, 2025Legislation
   HB 801, Public Chapter 1492025 regular session

   From July 1, 2025 the 2021 IECC roof solar reflectance and thermal emittance requirements for low-pitched roofs do not apply, and the fire marshal may make rules to implement.

   Enacted Apr 3, 2025, effective Apr 3, 2025, and Jul 1, 2025

   open.pluralpolicy.com (opens in a new tab)

How it was checked

Verified

Two separate readings of the state’s own record agree, and the passage is on file word for word.

Read twice: a second, blind reading of the state’s record agreed with the first on Oct 19, 2026.

The state’s record was last read on Oct 19, 2026, from five source pages.

Evidence 5 sources

Sources for the record itself come first, the state’s own records ahead of others. A label marks a source about something else, such as an exception. A source marked secondary is not the state’s own record.

• “For commercial buildings, the International Energy Conservation Code (IECC), 2021 edition,”

• “They become effective April 17, 2025.”

• About a law or bill

Tracker cross-checks

Code adoption trackers are a cross-check. They are not Tennessee’s own record.

• DOE’s energycodes.govCross-checkAgrees with the record

  Current state code: 2021 IECC and ASHRAE 90.1-2019; Effective date: 04/17/2025; Mandatory Statewide

  energycodes.gov (opens in a new tab)Read Oct 17, 2026

Related pages

• See Tennessee’s IECC commercial on the map
• IECC commercial adoption in every state
• All six codes in Tennessee

Other codes in Tennessee

• NEC2017 NECPartial
• IBC2021 IBCVerified
• IRC2018 IRCPartial
• IFC2021 IFCVerified
• IECC residential2018 IECCPartial