State facts
Ohio: homes, climate zones and who licenses the work
Ohio has 5.3 million housing units. 63.4% were built before 1980, and the median year built is 1970. 67.2% of occupied homes are lived in by their owners.
How old the homes are
Ohio 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 Ohio.
How homes are heated
How homes in Ohio are heated
Main heating fuel, share of 4.9 million occupied homes
- Utility gas 64.0%
- Electricity 26.0%
- Propane or other tank gas 5.6%
- Fuel oil or kerosene 1.7%
- Wood 1.4%
- Other fuel 0.7%
- No fuel used 0.5%
- Coal or coke 0.1%
- Solar energy <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 Ohio's residents divide among them, by the county they live in.
| IECC 2021 zone | Share of residents | Counties |
|---|---|---|
| 5A | 66.6% | 64 |
| 4A | 33.4% | 24 |
ENERGY STAR rates windows, doors and skylights for four climate zones of its own. Ohio spans 2: Northern (66.6% of residents), North-Central (33.4% of residents).
By NOAA's 1991–2020 climate normals, counties here average 116 days a year with a low of 32°F or colder, weighted by where people live. The range runs from 92 days in the mildest county to 148 in the coldest.
- SEER2 Requirements by State: What a New AC Must Meet
- What Size AC Do I Need? How a Load Calculation Answers It
- Do Heat Pumps Work in Cold Weather? What to Check Before Buying
- No Heat in Winter: How to Stay Safe Until the Furnace Is Fixed
- Ice Dams: Why They Leak Into Ceilings and How to Stop Them
- Crawl Space Moisture: Vented vs. Sealed Crawl Spaces
- Condensation on the Inside of Windows: Causes and Fixes
Flood risk and flood insurance
0.4% of residential structures in Ohio carry a National Flood Insurance Program policy: 18,040 policies, in FEMA's count as of August 3, 2026.
In FEMA's National Risk Index, 6 of 88 counties rate high or very high for riverine flooding.
Fire ants and termites
No county in Ohio is inside the federal imported fire ant quarantine.
Who licenses the work in Ohio
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 Pesticide Business License is required for anyone who applies pesticides for hire or performs wood-destroying insect inspections, and applicators are licensed in categories such as 10a (General Pest) and 10b (Termite). Agency: Ohio Department of Agriculture, Division of Plant Health, Pesticide Regulation. Look up a license. Who to call about pest control.
- Heating and cooling The state licenses HVAC contractors for commercial work; residential HVAC contractors are regulated by local building and health departments, which may require the state license. Agency: Ohio Construction Industry Licensing Board (OCILB), Ohio Department of Commerce, Division of Industrial Compliance. Look up a license. Who to call about heating and cooling.
- Window replacement and other home improvement No statewide license. Residential contractors are not required to be licensed by the state; local building departments may have their own licensing or registration. Who to call about window replacement.
- Mold remediation We found no statewide license for this work in official sources. Cities and counties may license it; ask the one where the house is. 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
- Ohio Department of Agriculture, Division of Plant Health, Pesticide Regulation agri.ohio.gov agri.ohio.gov
- Ohio Department of Agriculture, Division of Plant Health, Pesticide Regulation dam.assets.ohio.gov dam.assets.ohio.gov
- Ohio Department of Agriculture, Division of Plant Health, Pesticide Regulation agri.ohio.gov agri.ohio.gov
- Ohio Construction Industry Licensing Board (OCILB), Ohio Department of Commerce, Division of Industrial Compliance com.ohio.gov com.ohio.gov
- Ohio Construction Industry Licensing Board (OCILB), Ohio Department of Commerce, Division of Industrial Compliance elicense4.com.ohio.gov elicense4.com.ohio.gov
- com.ohio.gov com.ohio.gov com.ohio.gov
- epa.gov epa.gov epa.gov