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Reference

Codes, permits, and inspections
in Middle Tennessee.

Who issues your permit, which edition of the code you build to, what the energy code actually asks for in climate zone 4, and what the inspector looks at, stage by stage. Cheatham County first, then Ashland City, Nashville, and the counties around us. Every fact is cited to the agency's own page and dated. The office that issues your permit is the final word; when in doubt, call them, and bring the answer to our counter.

Where You Are Building (615) 792-5156
How Tennessee does it

One state code, and three kinds of county.

The State Fire Marshal's Office adopts the residential building code for the whole state: today the 2018 International Residential Code and the 2018 energy code, in force since July 16, 2020. When the state moved its commercial codes to the 2021 editions in April 2025, it left the house codes at 2018.

Every city and county then falls into one of three buckets. Exempt means it runs its own program with its own inspectors, and may adopt its own edition of the code; Cheatham County, Ashland City, Nashville, and every county around us are exempt. State program means the Fire Marshal's inspectors come out. Opted out means the local government passed a resolution and no residential code is enforced at all, though an owner can still request a state inspection and get a Certificate of Occupancy for it.

The practical rule: the office that issues your permit is the office whose edition you build to, and the permit names it.

What Tennessee changed

The amendments that matter at the counter.

Energy. The state rule replaces the 2018 insulation and window tables with the 2009 ones, makes the blower-door test optional (a visual inspection stands in), and makes duct testing optional. And since July 1, 2023, state law keeps every local government at that level for one- and two-family houses: no city or county may go stricter. That is why Nashville's 2024 energy code carries the same numbers as ours.

Fire sprinklers in houses are not mandatory in Tennessee. Electrical chapters of the IRC are replaced by the state electrical rule, and electrical permits are issued separately by the State.

Every material lesson on this site also cites the current model code (the 2021 IECC) so you can see where the numbers are headed. A window at U-0.30 and a ceiling at R-49 clear every code in the state with room to spare. The lessons explain why you might want to build above code anyway; this page tells you what code is.

Where You Are Building

Cheatham County, Ashland City, Nashville.

Three offices, each with its own edition and its own inspection routine. A lot inside Ashland City limits permits with the town; the rest of the county permits with the county.

Home county

Cheatham County (unincorporated)

  • Who issues the permit

    Cheatham County Department of Codes, Building Safety, and Land Use. 338 Frey Street, Ashland City. (615) 792-7915. Monday to Thursday, 7:30 to 4:30; applications until 4:00; closed Fridays.

  • Code edition

    2018 International Residential Code (with the 2018 IBC and 2018 IPMC). The county runs its own inspections; it is exempt from the state program.

  • Inspections

    Footing, foundation, framing with mechanical and plumbing rough-in, insulation, final. No occupancy until the building official issues the Certificate of Occupancy.

  • Separate permits

    Electrical permits come from the State (TDCI); septic from TDEC. Adequate-facilities tax and impact fees are paid here before a one- or two-family permit is issued, including for lots inside Ashland City.

Inside city limits

Town of Ashland City

  • Who issues the permit

    Building Codes, Planning and Zoning Department, 405 N Main Street, Ashland City. (615) 792-4211. Permit applications run through the town's online portal.

  • Code edition

    2018 ICC code cycle by town ordinance. The town runs its own inspections.

  • Who can pull it

    Licensed contractors. A homeowner may pull one permit every two years for their own residence.

  • Before the permit

    County adequate-facilities tax and impact fees are paid at the County Building Commissioner's office first. A construction-site maintenance ordinance has applied since August 2023.

Service area

Metro Nashville and Davidson County

  • Who issues the permit

    Metro Codes and Building Safety. (615) 862-6500; inspections scheduled at (615) 862-6550 or through ePermits for licensed contractors.

  • Code edition

    2024 International Residential Code and the rest of the 2024 I-Codes, adopted July 16, 2025, with the 2023 NEC. Projects designed under the 2018 codes had a 180-day grace period to mid-January 2026.

  • Energy code

    The 2024 IECC as adopted is amended to meet, and not exceed, the State's 2018 IECC as amended. The zone 4 values are the same as the rest of Tennessee.

  • Inspections

    Metro issues a project-specific inspection checklist with the permit rather than one published sequence. A Building Final is not performed until every trade permit (gas and mechanical, plumbing, electrical) is finaled; a Use and Occupancy letter follows.

The counties around us

CountyWho issues the permitCode editionNotes
Dickson CountyPlanning & Zoning, 4 Court Square, Charlotte. (615) 789-7003.Not stated on the county site; ask the office.Permits issued to the owner or the contractor only. The City of Dickson permits separately.
Robertson CountyPlanning Department, 511 S Brown St, Springfield. (615) 382-6198.2021 IBC and 2018 IECC named; IRC edition not stated.Trusses require a Tennessee engineer's stamp. A Home Improvement license county.
Williamson CountyBuilding Codes, 1320 West Main St, Franklin. (615) 790-5718.2021 IRC (sprinklers and electrical chapters excluded), 2018 IECC with the 2009 tables. Effective September 30, 2024.Published sequence: footings, foundation, slab, slab plumbing, framing, mechanical, plumbing, insulation, final and CO, storm water.
Sumner CountyBuilding & Codes, 355 N Belvedere Dr, Room 208, Gallatin. (615) 452-1467.2021 ICC codes, since May 19, 2023.
Montgomery CountyBuilding and Codes, 350 Pageant Lane, Suite 309, Clarksville. (931) 648-5718.2018 IRC, IBC, IPC, IFGC, IPMC, since January 1, 2021.Unincorporated county only; Clarksville permits separately.

All five counties run their own inspection programs (exempt on the State Fire Marshal's list, current to August 21, 2026). Cities inside them may permit separately. Confirm the edition with the office before you order windows or insulation.

Energy Code, Climate Zone 4

What the inspector asks for, and what the model code says.

Cheatham County and all of Middle Tennessee are climate zone 4A, mixed-humid. The first column is what is enforced here (the 2018 IECC with Tennessee's 2009 tables, and Nashville's 2024 code pinned to the same). The other two are the model codes the material lessons cite, so you can see the gap.

ComponentTennessee, as enforced2018 IECC (model)2021 IECC (model)
Window U-factor (max)0.350.320.30
Skylight U-factor (max)0.600.550.55
Window SHGC (max)not required0.400.40
CeilingR-38R-49R-60
Wood-frame wallR-13R-20, or R-13 + R-5 continuousR-30; R-20 + R-5 ci; R-13 + R-10 ci; R-20 ci alone
Floor over unconditioned spaceR-19R-19R-19
Basement wallR-10 ci or R-13R-10 ci or R-13R-10 ci or R-13
Slab edgeR-10, 2 ftR-10, 2 ftR-10 ci, 4 ft
Crawl-space wallR-10 ci or R-13R-10 ci or R-13R-10 ci or R-13
At the counter

A Low-E argon double-pane window at U-0.27 to 0.30 clears the Tennessee number and the 2021 number both; a builder-grade unit at U-0.35 clears only ours. R-38 in the ceiling passes here; R-49 is the model code and is one of the cheaper upgrades on the house because the attic is open and the blown-in is by the bag. The insulation lesson and the window label lesson run the numbers.

The Inspections

Five stops between the footing and the keys.

Cheatham County's sequence, which is also the shape of everyone else's. The state program folds the first two into one and skips the insulation stop; Williamson County adds slab, slab plumbing, and storm water; Nashville hands you a project-specific checklist with the permit. Electrical is inspected under its own state permit.

  1. Step 01

    Footing

    Before concrete: trench depth and width, rebar, and that the footing sits on undisturbed soil below frost. The state program calls this the foundation inspection.

  2. Step 02

    Foundation

    Walls or piers before backfill, anchor bolts, and (where there is one) the slab with its vapor retarder and any under-slab plumbing.

  3. Step 03

    Rough-in

    Framing, with the mechanical and plumbing rough-ins in the walls. Grade stamps, span tables, headers, hangers and their nails, engineered-wood reports, truss drawings, fire blocking, and window and door openings all get looked at here.

  4. Step 04

    Insulation

    R-values on the bags against the energy table, batts fitted without compression or gaps, air sealing at plates and penetrations, and the vapor retarder where one is called for. Nothing gets covered until it passes.

  5. Step 05

    Final

    Egress windows, tempered glass labels where the code wants them, smoke and CO alarms, handrails and guards, deck ledger and fasteners, GFCI protection, grading, and the house number. Passing it is what gets the Certificate of Occupancy.

What gets looked at, and the lesson for it

StageMaterialWhat the inspector readsLesson
Rough-inFraming lumber and engineered woodGrade stamp (agency, grade, species, moisture), APA stamp on sheathing, span tables, ICC-ES reports on I-joists and LVL, truss design drawings.Read the spec
Rough-inFasteners and connectorsThe nail or screw the hanger catalog calls for, hot-dip galvanized or stainless in treated lumber, ESR numbers on structural screws.Read the spec
Rough-inWindows and doorsOpenings framed to the maker's rough-opening sheet; egress sizes; tempered glass where the code requires it.Read the spec
InsulationInsulation and air sealingR-value on the bag against the zone 4 table, batts uncompressed, sealed plates and penetrations, the vapor retarder rule for zone 4A.Read the spec
FinalDecking and railsLedger attachment and flashing, joist hangers with the right nails, guard height and baluster spacing, stair rise and run.Read the spec
FinalRoofingUnderlayment and ice barrier where required, drip edge, flashing at walls and penetrations, fire class of the covering.Read the spec
FinalSiding and trimClearances at grade and roof, kick-out and step flashing, weather-resistive barrier, and the maker's nail schedule.Read the spec

Licenses

Who is allowed to bid the job.

$25,000 and up

Contractor's license

Required by the Tennessee Board for Licensing Contractors for any project whose total cost, labor and materials, is $25,000 or more, and required before you offer a price or bid. Masonry subcontractors: the portion over $100,000. License numbers are public on the board's site.

$3,000 to $24,999

Home Improvement license

Residential remodeling in that range needs a Home Improvement license only in the counties that adopted the law: Davidson and Robertson are on the list in our area. Cheatham, Dickson, Williamson, Sumner, and Montgomery are not.

For the money

Why an investor should ask

A licensed contractor has posted financials or a bond, carries the board's monetary limit, and can be looked up. An unlicensed bid at $25,000 or more is not a cheaper bid; it is a bid the permit office may not accept, on a house the buyer's lender will ask about.

Sources

Where each fact came from.

Checked 2026-09-02. Codes change; the office that issues your permit is the authority.
Tennessee adoption and amendments: SFMO codes history · Rule 0780-02-23 (July 2020) · SFMO jurisdictions list · opt-out jurisdictions · Public Chapter 312 (2023) · SFMO residential FAQs.
Cheatham County: Building & Codes · adopted codes and applications · required permits and inspections (rev. July 22, 2024). Ashland City: Building Codes, Planning and Zoning · residential permits.
Metro Nashville: adopted codes list · 2024 codes adoption (July 2025) · requesting an inspection · Use and Occupancy letter.
Neighbors: Dickson County · Robertson County · Williamson County adopted codes and inspections · Sumner County · Montgomery County.
Energy tables and climate zone: DOE Building America insulation table · fenestration table · climate regions by county. Licensing: Board for Licensing Contractors · Home Improvement license.

Frequently Asked

Codes and permits, answered.

Which building code does Cheatham County, Tennessee use?
The 2018 International Residential Code, with the 2018 IBC and 2018 IPMC, enforced by the county's own Department of Codes, Building Safety, and Land Use for the unincorporated county. The Town of Ashland City enforces the 2018 ICC cycle inside city limits through its own Building Codes department. Both run their own inspections rather than the state's. Checked 2026-09-02 against the county and town sites.
What energy code does Tennessee enforce for houses?
The 2018 IECC, amended: the state rule replaces the 2018 insulation and window tables with the 2009 ones, makes the blower-door test optional in favor of a visual inspection, and makes duct testing optional. In climate zone 4 that means windows at U-0.35 or lower, no solar-heat-gain limit, R-38 in the ceiling, R-13 in a wood-frame wall, and R-19 in a floor over unconditioned space. Since July 1, 2023, no city or county in Tennessee may enforce a stricter energy code on a one- or two-family house.
Do I need a permit to build a house in Ashland City?
Yes. Inside city limits the permit comes from the Town of Ashland City's Building Codes, Planning and Zoning Department, and the county's adequate-facilities tax and impact fees are paid at the County Building Commissioner's office first. Outside city limits the permit comes from Cheatham County. Electrical permits are separate, from the State, and septic permits come from TDEC.
What inspections does a new house need in Cheatham County?
Five, in order: footing, foundation, framing with the mechanical and plumbing rough-ins, insulation, and final. The house cannot be used or occupied until the building official issues the Certificate of Occupancy. The state program's own sequence, where it inspects, is foundation, slab, rough-in, and final.
Does Nashville use a different building code than the rest of Tennessee?
Yes, a newer one. Metro Nashville adopted the 2024 International Codes effective July 16, 2025, while the State and Cheatham County are on the 2018 editions and several neighboring counties are on 2021. The energy code is the exception: Metro amended its 2024 IECC to meet and not exceed the State's 2018 IECC as amended, so the insulation and window numbers are the same across the area.
Do I need a contractor's license in Tennessee?
For any project where the total cost, labor and materials, is $25,000 or more, yes: a license from the Tennessee Board for Licensing Contractors, required before you bid. Between $3,000 and $24,999 of residential remodeling, a Home Improvement license is required only in the counties that adopted that law; Davidson and Robertson are on the list, Cheatham is not. License numbers are public on the board's site; ask for it and check it.

Stop By the Desk

Let’s talk it through in person.

Bring your plans or just your questions. We’ll get you squared away.
119 Cumberland St, Ashland City. The coffee’s on.

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