Tennessee HVAC permit requirements

2018 International Residential Code (IRC) with Tennessee amendments (effective July 16, 2020), per Tenn. Comp. R. & Regs. 0780-02-23-.02(1)(a). The amendments: R313 sprinklers not mandatory; the IRC electrical chapters are deleted; the seismic figure is replaced; an R314.6 exception is added; N1102.4.1.2 testing is replaced with the 2009 IRC testing/visual-inspection option; N1103.3.3/N1103.3.4 duct testing and duct leakage are made optional; the 2018 insulation/U-factor tables are replaced with the 2009 IRC tables; N1102.4.4 is deleted; log-wall footnotes are added. No amendment touches Chapters 14 or 16 (mechanical).

One- and two-family dwellings and townhomes: 2018 IECC with state amendments (effective July 16, 2020). R402.4.1.2 testing is replaced with the 2009 IECC testing option / visual inspection option. R403.3.3 duct testing and R403.3.4 duct leakage are optional. Tables R402.1.2/R402.1.4 are replaced with 2009 IECC Tables 402.1.1/402.1.3. Commercial uses the 2021 IECC (effective April 17, 2025).

2018 IRC M1401.3 is kept; the 0780-02-23-.02(1)(a) amendment list does not touch Chapter 14. M1401.3: equipment 'shall be sized in accordance with ACCA Manual S or other approved sizing methodologies based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies.' 2018 IECC R403.7 (same Manual S/J language) is also not among the IECC amendments in .02(1)(b).

2018 IRC M1601.1 is kept (not in the state amendment list). Duct systems 'shall be installed in accordance with the provisions of this section and ACCA Manual D, the appliance manufacturer's installation instructions or other approved methods.' Alternatives to Manual D are allowed.

Rule 0780-02-23-.05 requires a state building permit only for 'construction': new one- and two-family dwellings or townhouses, change of occupancy, and additions of 30 sq ft or more of interior space. 'Construction' expressly excludes 'renovation'. The rule and the SFMO pages do not address standalone HVAC changeouts.

SFMO FAQ: 'energy code compliance to be met through meeting the standards of either Chapter 11 of the 2018 IRC or the 2018 edition of the International Energy Conservation Code.' Envelope testing may be replaced by the 2009 visual inspection option. Named tools (REScheck/performance/ERI) are not stated in state sources.

The permit form must state 'location where the work will be performed', 'a description of the work', 'use and occupancy', 'valuation', 'square footage', and the applicant's signature, plus proof of licensure (T.C.A. Title 62, Ch. 6). Since Oct 1, 2011, 'plumbing and mechanical systems' are inspected at rough-in and final. No load-calculation submittal is listed.

core.tn.gov