City of Brentwood, Tennessee - Planning and Codes Department

City of Brentwood, Williamson County, Tennessee

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Brentwood, TN

Required

The Codes Enforcement Section lists the adopted building codes as the International Residential Code, 2018 edition, including appendices E and F; the International Building Code, 2018 edition; the International Energy Conservation Code, 2018 edition; the International Swimming Pool and Spa Code, 2018 edition including appendices A and B; the International Property Maintenance Code; and the 2017 National Electrical Code, which the city notes is regulated and enforced by the State Fire Marshal's Office rather than by the city. The codified provisions sit in Brentwood Municipal Code Chapter 14, Buildings and Building Regulations, current through Supplement No. 58, Update 1. Tennessee sets a statewide minimum of the 2018 International Residential Code for one- and two-family dwellings and requires a local government's adopted edition to be "current within seven (7) years of the date of the latest edition published," so a Tennessee city may adopt a newer code than the state minimum but not an older one.

Not required — Brentwood imposes no impact-resistance or hail-rating requirement on roof coverings. Municipal Code Chapter 14, Buildings and Building Regulations, was read in full and contains no reference to UL 2218, to FM 4473, or to a Class 4 or Class IV impact classification, and no requirement of that kind expressed in any other wording. Nor does it amend any provision of the roof assemblies chapter of the adopted residential code, so nothing in the model text has been stiffened in this direction either.

Brentwood publishes no dollar or square-footage threshold for roofing, and it has one provision about roofs that a roofer should read carefully because it exempts something other than the permit. Municipal Code section 14-71 is headed "Seal exemptions" and opens: "Plans and specifications for all buildings and structures shall be submitted by a registered architect or engineer, subject to the following exceptions." Its item (5), headed Roofing design, reads: "Normal maintenance, repair or replacement of an existing roof where the weight, drainage, fire protection, and other code related requirements of the original design are not changed or compromised." THAT IS AN EXEMPTION FROM SEALED PLANS, NOT FROM A PERMIT. It means an ordinary reroof does not need drawings stamped by an architect or engineer; it does not remove the work from the permit requirement, and reading it as though it did would be an expensive mistake. The city's separate list of local modifications to section R105.2 of the residential code, the provision that actually governs work exempt from a permit, reaches accessory structures, fences over seven feet high, decks and playground equipment - roofing is not among them. Note also that the seal exemption is conditional on its own terms: a reroof that changes the weight, the drainage or the fire protection of the original design falls outside it.

Two layers maximum - one overlay is permitted, and a second existing layer requires a tear-off. Brentwood adopts the 2018 International Residential Code and its Municipal Code Chapter 14 was read in full - roughly a hundred thousand characters covering adoption, administration, permits, fees, seal exemptions, inspections and the local modification list. It contains no amendment to section R908 or to any part of the roof assemblies chapter, so the adopted code text governs unchanged. Section R908.3.1.1 of the 2018 International Residential Code provides that a roof recover shall not be permitted where any of three conditions occur, the third being "where the existing roof has two or more applications of any type of roof covering." One existing layer may be recovered; a second forces removal. The other two conditions apply whatever the layer count: a covering that is water soaked or has deteriorated to the point that it is not an adequate base for additional roofing, and a covering of slate, clay, cement or asbestos-cement tile. TENNESSEE PUTS A FLOOR UNDER THIS THAT IS WORTH KNOWING: the statewide minimum for one- and two-family dwellings is the 2018 International Residential Code, and Tenn. Comp. R. & Regs. 0780-02-23-.12(2) provides that "no city, county, town, municipal corporation, metropolitan government, or political subdivision of the State of Tennessee shall adopt or enforce any ordinance prescribing less stringent standards ... than those established hereunder" without the state fire marshal's written approval. A Tennessee jurisdiction may therefore be stricter than the two-layer rule but cannot be more permissive than it.

9.25% in the City of Brentwood - the 7% Tennessee state sales tax plus the 2.25% local tax levied by the city. Tennessee sets the state rate and lets each county or incorporated city levy its own local tax on top: the Department of Revenue states that "any county or incorporated city, by resolution or ordinance, may levy the local sales and use tax on the same privileges that are subject to the state's sales or use tax," and that "the local tax rate may not be higher than 2.75% and must be a multiple of .25." THAT CAP IS WHY A CITY RATE IS NOT ADDED TO ITS COUNTY RATE: several Tennessee cities levy the full 2.75% while sitting in a county that levies less, and stacking the two would exceed the statutory maximum. Where an incorporated city has its own rate, that rate is the local rate inside the city; where it has none, the county rate applies. The figures here are from the Department of Revenue's own machine-readable rate file for the third quarter of 2026, which the Department publishes for use in tax calculation applications. BRENTWOOD IS THE CASE THAT PROVES THE POINT ABOVE, AND IT RUNS THE UNEXPECTED WAY. Williamson County levies 2.75%, the statutory maximum, but the City of Brentwood levies 2.25% and the city rate is what applies inside the city. A job in Brentwood is therefore half a point cheaper on tax than a job in the unincorporated county around it, and quoting the county rate inside the city would overstate the tax.