State facts
Tennessee: homes, climate zones and who licenses the work
Tennessee has 3.1 million housing units. 40.8% were built before 1980, and the median year built is 1987. 66.9% of occupied homes are lived in by their owners.
How old the homes are
Tennessee housing units, by year built
Layers drawn to scale
Age changes what applies to a house. In general, anyone paid to do work that disturbs painted surfaces in a home built before 1978 must be certified in lead-safe work practices under the EPA's Renovation, Repair and Painting Rule, which the EPA administers directly in Tennessee.
How homes are heated
How homes in Tennessee are heated
Main heating fuel, share of 2.8 million occupied homes
- Electricity 63.7%
- Utility gas 30.5%
- Propane or other tank gas 3.6%
- Wood 1.1%
- No fuel used 0.5%
- Fuel oil or kerosene 0.3%
- Other fuel 0.2%
- Solar energy <0.1%
- Coal or coke <0.1%
Climate and building zones
The 2021 International Energy Conservation Code assigns every county a climate zone from 1 to 8 and a moisture regime: A for moist, B for dry, C for marine. Zones 7 and 8 have no letter. Here is how Tennessee's residents divide among them, by the county they live in.
| IECC 2021 zone | Share of residents | Counties |
|---|---|---|
| 3A | 51.6% | 34 |
| 4A | 48.4% | 61 |
ENERGY STAR rates windows, doors and skylights for four climate zones of its own. Tennessee spans 2: South-Central (51.6% of residents), North-Central (48.4% of residents).
By NOAA's 1991–2020 climate normals, counties here average 83 days a year with a low of 32°F or colder, weighted by where people live. The range runs from 63 days in the mildest county to 126 in the coldest.
Flood risk and flood insurance
0.7% of residential structures in Tennessee carry a National Flood Insurance Program policy: 18,014 policies, in FEMA's count as of August 3, 2026.
In FEMA's National Risk Index, 4 of 95 counties rate high or very high for riverine flooding.
Fire ants and termites
87 of Tennessee's 95 counties are inside the federal imported fire ant quarantine, home to 93.4% of its residents. The federal quarantine requires a certificate to move soil, sod, nursery plants with soil attached, used soil-moving equipment, and hay or straw stored on the ground out of the quarantined area.
Who licenses the work in Tennessee
Before anyone starts work, check the license with the agency below. Where the state does not license a trade, cities and counties may; ask the one where the house is.
- Pest control A company offering custom pesticide application must hold a pest control charter for each location, with at least one licensee in each category of service offered; household pest work falls under the General Pest and Rodent Control (GRC) license. Agency: Tennessee Department of Agriculture. Who to call about pest control.
- Heating and cooling HVAC contractors need a state contractor's license with the CMC-C (HVAC, Refrigeration and Gas Piping) or CMC classification for projects of $25,000 or more; smaller HVAC jobs are regulated locally. Agency: Tennessee Board for Licensing Contractors (Department of Commerce and Insurance). Look up a license. Who to call about heating and cooling.
- Window replacement and other home improvement A state contractor's license is required for projects of $25,000 or more; a Home Improvement license is required for residential remodeling from $3,000 to $24,999 only in the counties that adopted the law. Agency: Tennessee Board for Licensing Contractors (Department of Commerce and Insurance). Look up a license. Who to call about window replacement.
- Mold remediation Mold remediation is a specialty classification (S-F Mold Remediation) of the state contractor's license, which applies to projects of $25,000 or more. Agency: Tennessee Board for Licensing Contractors (Department of Commerce and Insurance). Look up a license. Who to call about water damage and mold.
Checked 2026-09-29. Licensing rules change; the agency's own page is the authority.
Sources
- U.S. Census Bureau American Community Survey 2020–2024 5-year estimates, tables B25034, B25035, B25040 and B25003 data.census.gov
- Pacific Northwest National Laboratory Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates basc.pnnl.gov
- U.S. Department of Energy Prototype Building Models (climate zones 1–8 and moisture regimes A, B, C) energycodes.gov
- ENERGY STAR Climate zones by county for windows, doors and skylights energystar.gov
- NOAA National Centers for Environmental Information U.S. Climate Normals 1991–2020, annual and seasonal ncei.noaa.gov
- Federal Emergency Management Agency OpenFEMA NFIP Residential Penetration Rates (as of 2026-08-03) fema.gov
- Federal Emergency Management Agency National Risk Index, county ratings fema.gov
- USDA Animal and Plant Health Inspection Service Imported fire ant quarantine map aphis.usda.gov
- Electronic Code of Federal Regulations 7 CFR part 301, subpart P, Imported Fire Ant ecfr.gov
- Tennessee Department of Agriculture tn.gov tn.gov
- Tennessee Board for Licensing Contractors (Department of Commerce and Insurance) support.commerce.tn.gov support.commerce.tn.gov
- Tennessee Board for Licensing Contractors (Department of Commerce and Insurance) support.commerce.tn.gov support.commerce.tn.gov
- Tennessee Board for Licensing Contractors (Department of Commerce and Insurance) tn.gov tn.gov
- Tennessee Board for Licensing Contractors (Department of Commerce and Insurance) tn.gov tn.gov
- epa.gov epa.gov epa.gov