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Connecticut: homes, climate zones and who licenses the work

Connecticut has 1.5 million housing units. 67.2% were built before 1980, and the median year built is 1967. 66.5% of occupied homes are lived in by their owners.

How old the homes are

Connecticut housing units, by year built

Layers drawn to scale

Connecticut housing units by year built 67.2% of Connecticut housing units were built before 1980 and 32.8% in 1980 or later. 2020 or later: 0.7%; 2010–2019: 4.5%; 2000–2009: 7.1%; 1990–1999: 7.5%; 1980–1989: 12.9%; 1970–1979: 13.7%; 1960–1969: 13.0%; 1950–1959: 14.1%; 1940–1949: 6.3%; 1939 or earlier: 20.2%. Before 1980 67.2% 1980 or later 32.8% 2020 or later 0.7% 2010–2019 4.5% 2000–2009 7.1% 1990–1999 7.5% 1980–1989 12.9% 1970–1979 13.7% 1960–1969 13.0% 1950–1959 14.1% 1940–1949 6.3% 1939 or earlier 20.2%
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, tables B25034, B25035 and B25003; heating fuel below from B25040.

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 Connecticut.

How homes are heated

How homes in Connecticut are heated

Main heating fuel, share of 1.4 million occupied homes

  • Utility gas 36.3%
  • Fuel oil or kerosene 36.3%
  • Electricity 18.4%
  • Propane or other tank gas 5.8%
  • Wood 1.4%
  • Other fuel 1.0%
  • No fuel used 0.5%
  • Solar energy 0.2%
  • Coal or coke <0.1%
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, table B25040 (occupied housing units).

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 Connecticut's residents divide among them, by the county they live in.

IECC 2021 zoneShare of residentsCounties

ENERGY STAR rates windows, doors and skylights for four climate zones of its own. Connecticut spans 0: .

By NOAA's 1991–2020 climate normals, counties here average 121 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 152 in the coldest.

Flood risk and flood insurance

2.1% of residential structures in Connecticut carry a National Flood Insurance Program policy: 21,002 policies, in FEMA's count as of August 3, 2026.

In FEMA's National Risk Index, 5 of 9 counties rate high or very high for riverine flooding; 3 of 9 counties rate high or very high for coastal flooding; 6 of 9 counties rate high or very high for hurricanes.

Fire ants and termites

No county in Connecticut is inside the federal imported fire ant quarantine.

Who licenses the work in Connecticut

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.

Checked 2026-09-29. Licensing rules change; the agency's own page is the authority.

Sources

  1. U.S. Census Bureau American Community Survey 2020–2024 5-year estimates, tables B25034, B25035, B25040 and B25003 data.census.gov
  2. Pacific Northwest National Laboratory Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates basc.pnnl.gov
  3. U.S. Department of Energy Prototype Building Models (climate zones 1–8 and moisture regimes A, B, C) energycodes.gov
  4. ENERGY STAR Climate zones by county for windows, doors and skylights energystar.gov
  5. NOAA National Centers for Environmental Information U.S. Climate Normals 1991–2020, annual and seasonal ncei.noaa.gov
  6. Federal Emergency Management Agency OpenFEMA NFIP Residential Penetration Rates (as of 2026-08-03) fema.gov
  7. Federal Emergency Management Agency National Risk Index, county ratings fema.gov
  8. USDA Animal and Plant Health Inspection Service Imported fire ant quarantine map aphis.usda.gov
  9. Electronic Code of Federal Regulations 7 CFR part 301, subpart P, Imported Fire Ant ecfr.gov
  10. Connecticut Department of Energy and Environmental Protection portal.ct.gov portal.ct.gov
  11. Connecticut Department of Energy and Environmental Protection portal.ct.gov portal.ct.gov
  12. Connecticut Department of Consumer Protection cga.ct.gov cga.ct.gov
  13. Connecticut Department of Consumer Protection portal.ct.gov portal.ct.gov
  14. Connecticut Department of Consumer Protection portal.ct.gov portal.ct.gov
  15. Connecticut Department of Consumer Protection cga.ct.gov cga.ct.gov
  16. portal.ct.gov portal.ct.gov portal.ct.gov
  17. epa.gov epa.gov epa.gov