Williamson County, Tennessee - Building Codes Department

Unincorporated Williamson County, Tennessee

county

1320 West Main St., Franklin, TN 37064

Not required

Required

Williamson County (unincorporated) has adopted and enforces the 2021 edition of the International Residential Code. The County's Building Codes Department states it in its own signed guidance letter of August 1, 2025, over the name of the Director/Building Official: "Williamson County (unincorporated) adopted and enforces the 2021 version of the International Residential Code (IRC)." The same letter directs that reroofing work "shall comply with adopted codes and ordinances, including Chapter 9/Roof Assemblies of the 2021 IRC" even where no permit is required. Whether the County has enacted local amendments to that code has not been established here; no county amendment list was read, so no claim is made either way.

Not required — No inspection of any kind is required for a residential roof repair or replacement in unincorporated Williamson County, so there is no mid-roof, deck, dry-in or final stage to schedule. The County's own August 1, 2025 guidance letter states it directly: "a building permit and inspection is not required for residential roof repairs or replacements," and again "Even though a permit and inspection is not required for a roof repair or replacement..." The letter closes by saying the Building and Neighborhood Services Department "is regularly asked about roof repairs and replacements and there is no other action for us in such cases." The absence of a mid-roof inspection here follows from the absence of any permit at all, which is a different situation from a jurisdiction that permits the work and inspects it only once at completion.

NO PERMIT AT ANY SIZE, and no dollar or square-footage threshold exists to cross. This is unusual and it is the County's own published position, not an inference. Williamson County Building Codes issues a standing letter, "Re: Code Requirements for Roof Repair or Replacement," dated August 1, 2025 and signed by the Director/Building Official, which reads: "Per section R105.2.2 of the Code, application or notice to the Building Official is not required for ordinary repairs to structures. Accordingly, a building permit and inspection is not required for residential roof repairs or replacements." The letter applies to repairs and to full replacements alike and sets no size, cost or scope limit on the exemption. Two limits do apply and the County states both. First, quoting IRC Section R105.2: "exemption from permit requirements of the Code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction." Second: "Even though a permit and inspection is not required for a roof repair or replacement the construction shall comply with adopted codes and ordinances, including Chapter 9/Roof Assemblies of the 2021 IRC," and "roof assemblies and materials shall be installed in accordance with the manufacturer's installation instructions." So the work is unpermitted, not unregulated: the code still governs, there is simply no county application, fee or inspection attached to it. This applies in the unincorporated county only — Franklin, Brentwood, Nolensville, Thompson's Station, Fairview and the Williamson County portion of Spring Hill run their own permitting.

9.75% combined. That is the Tennessee state rate of 7.00% plus the Williamson County local-option rate of 2.75%. The county rate was read directly from the Tennessee Department of Revenue's own quarterly Streamlined Sales Tax rate file for the quarter beginning July 1, 2026, jurisdiction code 187 (Williamson County), which carries 2.75% with an effective date of April 1, 2018 and no end date — the same file shows the prior 2.25% rate running from April 1, 1991 to March 31, 2018. Tennessee's local sales tax is levied at the county level with no separate city add-on layer, so 9.75% applies throughout Williamson County, inside its municipalities as well as in the unincorporated area this record covers.