Window Replacement in Tennessee: Licenses and Climate
Replacing windows in Tennessee: when a state contractor license applies, the home improvement license in nine counties, Verify a License and ENERGY STAR zones.
In Tennessee, two state licenses may apply to a window job, and which one depends on the price and the county. The Tennessee Board for Licensing Contractors says a contractor's license is required before contracting, including bidding, "for projects of $25,000 or more" when acting as a prime contractor, one who contracts directly with the owner (Board: contractor license) 2. Below that, a home improvement license is required for residential remodeling projects from $3,000 to $24,999, but only in the counties that adopted the law: Bradley, Davidson, Hamilton, Haywood, Knox, Marion, Robertson, Rutherford and Shelby (Board: home improvement contractor) 1.
Both can be checked in the state's Verify a License search 34. The other half of the answer is climate: Tennessee's counties fall into ENERGY STAR's North-Central and South-Central window zones, roughly two to one 7.
The $25,000 contractor license
The board's contractor page sets the line at the project value. A contractor's license is needed for projects of $25,000 or more when acting as a prime contractor, certain subcontractor, or construction manager or consultant, and the requirement applies before contracting, "including bidding, offering to engage, or negotiating a price" (Board: contractor license) 2. The board's home page says the licensing requirements for contractors and home improvement contractors are in Tennessee Code Annotated, Title 62, Chapter 6 (Board for Licensing Contractors) 3.
The figure is a project value, not a per-window price, so the total on your written quote is the number to hold against it 2.
The home improvement license in nine counties
For residential jobs below the contractor line, the board describes a separate home improvement license. In its words, "a Home Improvement license is required for residential remodeling projects from $3,000 to $24,999; however, this only applies to the counties adopting the law" (Board: home improvement contractor) 1. The board lists nine counties 1:
- Bradley, Davidson, Hamilton, Haywood and Knox
- Marion, Robertson, Rutherford and Shelby
That list takes in Nashville (Davidson), Memphis (Shelby), Knoxville (Knox), Chattanooga (Hamilton) and Murfreesboro (Rutherford). The board says home improvement is defined in T.C.A. 62-6-501(4)(A) and includes improvements "such as repair, replacement, remodeling, alterations, or additions to any land or residential building" 1. The license calls for a surety bond of $10,000 and proof of general liability and workers' compensation coverage, among other items 1.
What it means for a window job
A window replacement on a home priced between $3,000 and $24,999 in one of those nine counties is the kind of job to check against this license 1. Outside those counties, the board's page does not describe a state home improvement license for that price range, so ask your city or county building office whether any local rule applies 1. Is the installer licensed by the board for this job size and county? The guide on how to choose a window installer covers references, written contracts and warranties.
How to verify a Tennessee license
The board's page links Verify a License 3. The state's Verify a License or Credential search looks up a license, credential, permit or registration for a person or business, and filters by last name, first name, organization name, board or program, license type, status, license number, city, state, ZIP code and county. The page says results update daily 4. Check that the company name and license number on the quote match, and that the license type fits the job.
The Nashville window replacement page covers local rules in Nashville and Davidson County. Whether your own job needs a permit depends on your city or county; the article on window replacement permits explains why answers differ.
Tennessee's climate, east to west
The 2025 State Climate Summary for Tennessee, from the North Carolina Institute for Climate Studies at North Carolina State University, says the state's central Southeast location exposes it to warm, humid air from the Gulf and to air masses from the continental interior, and that temperatures drop about 3°F per 1,000 feet of elevation gain 5. The summary notes that the Cumberland Plateau and the Great Smoky Mountains are noticeably cooler than the Great Valley of East Tennessee 5.
| Feature | What the summary reports |
|---|---|
| Summer highs | Low 80s°F in the East Tennessee mountains to low 90s°F in West Tennessee (1991 to 2020) 5 |
| January lows | Below 25°F in the far northeast; above 30°F in the southwest 5 |
| Seasonal averages | Winter 39.1°F, summer 75.8°F (long-term) 5 |
| Annual precipitation | Generally 45 to 60 inches; long-term average 52.3 inches 5 |
| Snowfall | 1 to 4 inches a year in the south to nearly a foot in the northeast, more in the Smokies 5 |
| Tornadoes | About 30 a year on average, 1995 to 2024 5 |
For windows, that means a real heating season in the higher, cooler east and hotter summers in West Tennessee 5. With 45 to 60 inches of precipitation a year in most places, ask how the installer will flash and seal each opening 5.
ENERGY STAR zones for Tennessee counties
ENERGY STAR sets window criteria by climate zone, based on ratings from the National Fenestration Rating Council (NFRC) (ENERGY STAR criteria) 8. ENERGY STAR's county list puts Tennessee's 95 counties in two zones (climate zone finder) 7:
| ENERGY STAR zone | Tennessee counties | U-factor | SHGC |
|---|---|---|---|
| North-Central | 61 counties, including Knox, Sullivan, Washington, Montgomery, Sumner, Wilson, Blount, Putnam | 0.25 or less | 0.40 or less 67 |
| South-Central | 34 counties, including Davidson, Shelby, Hamilton, Rutherford, Williamson, Madison, Maury, Tipton | 0.28 or less | 0.23 or less 67 |
Every ENERGY STAR window, in any zone, must also meet an air leakage limit of 0.3 cubic feet per minute per square foot 6.
Nashville, Memphis and Chattanooga are in South-Central counties; Knoxville, Clarksville and the Tri-Cities are in North-Central ones 7. The line runs close to home in Middle Tennessee: Davidson, Williamson and Rutherford are South-Central, while Sumner and Wilson, just to the north and east, are North-Central 7. Check your own county in the finder.
What the numbers mean
- U-factor measures how fast heat moves through the whole window; lower insulates better. The North-Central limit of 0.25 is tighter than South-Central's 0.28 6. The U-factor explainer covers how it is measured.
- SHGC (solar heat gain coefficient) is the share of the sun's heat that passes through. South-Central caps it at 0.23, which matters on west- and south-facing glass in hot West Tennessee summers; North-Central allows up to 0.40, letting more winter sun in 56. The article on the solar heat gain coefficient explains the trade-off.
The energy-efficient windows explainer and the article on low-E glass go deeper on reading the NFRC label.
Cost and next steps
Tennessee prices follow the same drivers as anywhere: the number of windows, frame material, glass package, installation method and labor. This article does not quote Tennessee prices, because the national surveys do not publish reliable state figures; the window replacement cost guide sets them side by side. Licensing works differently next door in North Carolina. Ask each installer to quote the same window, glass and installation method in writing, then use the article on how to compare window quotes.
When you are ready, you can compare quotes from window installers.
About these figures
- 1 Official record: Board for Licensing Contractors home improvement page ($3,000 to $24,999 residential remodeling, the nine adopting counties, the T.C.A. 62-6-501(4)(A) definition, $10,000 surety bond and coverage requirements), checked October 27, 2026.
- 2 Official record: Board for Licensing Contractors contractor page (license required before contracting or bidding on projects of $25,000 or more as a prime contractor), checked October 27, 2026.
- 3 Official record: Board for Licensing Contractors home page (Title 62, Chapter 6, and the Verify a License link), checked October 27, 2026.
- 4 Official record: Department of Commerce and Insurance Verify a License or Credential search fields and daily updates, checked October 27, 2026.
- 5 Reported: North Carolina Institute for Climate Studies 2025 State Climate Summary for Tennessee (Gulf and continental air, 3°F per 1,000 feet, summer highs, January lows, 39.1°F winter and 75.8°F summer averages, 45 to 60 inches and 52.3 inches of precipitation, snowfall, about 30 tornadoes a year from 1995 to 2024), checked October 27, 2026.
- 6 Official record: ENERGY STAR window criteria for the North-Central and South-Central zones and the 0.3 air leakage limit, checked October 27, 2026.
- 7 Official record: ENERGY STAR county climate zone list for Tennessee (95 counties: 61 North-Central, 34 South-Central), checked October 27, 2026.
- 8 Official record: ENERGY STAR statement that window criteria rest on NFRC ratings and vary by climate zone, checked October 27, 2026.
Sources
- Home Improvement Contractor, Tennessee Board for Licensing Contractors, Department of Commerce and Insurance (Official record). Checked October 26, 2026.
- Contractor, Tennessee Board for Licensing Contractors, Department of Commerce and Insurance (Official record). Checked October 26, 2026.
- TN Board for Licensing Contractors, Tennessee Board for Licensing Contractors, Department of Commerce and Insurance (Official record). Checked October 26, 2026.
- Verify a License or Credential, Tennessee Department of Commerce and Insurance (Official record). Checked October 26, 2026.
- State Climate Summaries 2025: Tennessee, North Carolina Institute for Climate Studies, North Carolina State University (Other). Checked October 26, 2026.
- ENERGY STAR Certification Criteria for Residential Windows, ENERGY STAR (U.S. Environmental Protection Agency) (Official record). Checked October 26, 2026.
- Windows, Doors, and Skylights Climate Zone Finder (with the county climate zone spreadsheet), ENERGY STAR (U.S. Environmental Protection Agency) (Official record). Checked October 26, 2026.
- What makes it ENERGY STAR? (residential windows, doors and skylights), ENERGY STAR (U.S. Environmental Protection Agency) (Official record). Checked October 26, 2026.