State facts
Home facts by state
Each state page covers the age of its homes, how they are heated, the building climate zones, flood insurance, fire ants, and which agency licenses pest control, heating and cooling, home improvement and mold work.
| State | Housing units | Built before 1980 | Median year built | Main IECC 2021 zone |
|---|---|---|---|---|
| Alaska | 328,491 | 36.8% | 1986 | 7 (67.3% of residents) |
| Alabama | 2,337,265 | 42.1% | 1986 | 3A (80.6% of residents) |
| Arkansas | 1,394,673 | 39.6% | 1987 | 3A (75.5% of residents) |
| Arizona | 3,192,839 | 29.3% | 1992 | 2B (85.5% of residents) |
| California | 14,644,735 | 56% | 1976 | 3B (75.9% of residents) |
| Colorado | 2,589,053 | 39.7% | 1988 | 5B (93.7% of residents) |
| Connecticut | 1,541,822 | 67.2% | 1967 | (% of residents) |
| District of Columbia | 361,014 | 69% | 1958 | 4A (100% of residents) |
| Delaware | 464,203 | 41.9% | 1987 | 4A (100% of residents) |
| Florida | 10,256,470 | 34% | 1988 | 2A (71.6% of residents) |
| Georgia | 4,541,835 | 31.5% | 1992 | 3A (86.5% of residents) |
| Hawaii | 567,896 | 50.5% | 1980 | 1A (100% of residents) |
| Iowa | 1,437,699 | 61.6% | 1972 | 5A (89.1% of residents) |
| Idaho | 795,014 | 39% | 1991 | 5B (71.6% of residents) |
| Illinois | 5,457,452 | 63.5% | 1971 | 5A (88.9% of residents) |
| Indiana | 2,976,568 | 55% | 1976 | 5A (55.1% of residents) |
| Kansas | 1,293,635 | 55.9% | 1976 | 4A (97.9% of residents) |
| Kentucky | 2,023,116 | 47.1% | 1982 | 4A (100% of residents) |
| Louisiana | 2,108,902 | 46.3% | 1983 | 2A (78.5% of residents) |
| Massachusetts | 3,030,406 | 67.4% | 1964 | 5A (100% of residents) |
| Maryland | 2,560,784 | 51.2% | 1979 | 4A (98.4% of residents) |
| Maine | 751,876 | 54.4% | 1977 | 6A (95.1% of residents) |
| Michigan | 4,622,236 | 62.1% | 1972 | 5A (88.7% of residents) |
| Minnesota | 2,545,030 | 52.1% | 1979 | 6A (87.3% of residents) |
| Missouri | 2,825,287 | 52.7% | 1978 | 4A (95% of residents) |
| Mississippi | 1,341,114 | 41.5% | 1986 | 3A (83.1% of residents) |
| Montana | 528,419 | 48.9% | 1981 | 6B (100% of residents) |
| North Carolina | 4,895,668 | 33.9% | 1991 | 3A (89.4% of residents) |
| North Dakota | 377,281 | 47.8% | 1982 | 6A (71.8% of residents) |
| Nebraska | 863,444 | 57.2% | 1975 | 5A (100% of residents) |
| New Hampshire | 648,472 | 51.5% | 1979 | 5A (79.7% of residents) |
| New Jersey | 3,791,354 | 62.8% | 1970 | 4A (66.6% of residents) |
| New Mexico | 956,964 | 42.7% | 1985 | 4B (44.1% of residents) |
| Nevada | 1,326,471 | 22% | 1996 | 3B (73% of residents) |
| New York | 8,585,241 | 73.9% | 1959 | 4A (62.5% of residents) |
| Ohio | 5,292,391 | 63.4% | 1970 | 5A (66.6% of residents) |
| Oklahoma | 1,775,127 | 49.4% | 1980 | 3A (90.5% of residents) |
| Oregon | 1,857,992 | 49.1% | 1981 | 4C (86.4% of residents) |
| Pennsylvania | 5,806,452 | 67.2% | 1965 | 4A (51.2% of residents) |
| Rhode Island | 485,932 | 70.9% | 1962 | 5A (100% of residents) |
| South Carolina | 2,443,039 | 32.8% | 1992 | 3A (95.7% of residents) |
| South Dakota | 408,584 | 49.7% | 1980 | 6A (86.2% of residents) |
| Tennessee | 3,143,670 | 40.8% | 1987 | 3A (51.6% of residents) |
| Texas | 12,128,515 | 33.2% | 1992 | 2A (68.7% of residents) |
| Utah | 1,223,468 | 35.5% | 1992 | 5B (89.8% of residents) |
| Virginia | 3,684,756 | 43.5% | 1984 | 4A (79.2% of residents) |
| Vermont | 339,042 | 56% | 1976 | 6A (100% of residents) |
| Washington | 3,306,620 | 43.4% | 1985 | 4C (72.2% of residents) |
| Wisconsin | 2,778,572 | 57% | 1975 | 5A (68.5% of residents) |
| West Virginia | 861,325 | 55.9% | 1976 | 4A (68.9% of residents) |
| Wyoming | 277,141 | 49.1% | 1981 | 6B (70% of residents) |
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