How Old Is Treasure Valley Housing? Lead Paint and Asbestos Exposure by City
U.S. Census Bureau ACS, EPA, OSHA. Data covers 2020 to 2024 (American Community Survey 5-year estimates).
Summary
In Boise, 42.0% of housing units, about 44,700, were built before 1980, the closest Census cut-off to the 1978 federal ban on lead paint. In Meridian the share is 6.6%. Boise holds 77.0% of Ada County's pre-1980 housing but 50.3% of its housing overall. Older homes are where lead paint and asbestos rules most often apply during a remodel.
Boise has the oldest housing of the eight Treasure Valley cities measured, with a median year built of 1986 (±2). Star has the newest, at 2011 (±2). Source [2]
In Boise, 42.0% (±1.3 points) of housing units, an estimated 44,682, were built before 1980, compared with 6.6% (±0.9) in Meridian, 6.5% (±4.1) in Star and 7.3% (±2.4) in Kuna. Our calculation from [1]
Boise contains 77.0% of Ada County's pre-1980 housing units (44,682 of 58,054) while holding 50.3% of the county's total housing units. Our calculation from [1]
Across Ada and Canyon counties combined, an estimated 85,319 housing units, 28.4% of 300,575, were built before 1980. Our calculation from [1]
The Treasure Valley's housing is newer than the nation's: 49.7% of U.S. housing units were built before 1980, against 39.0% in Idaho, 30.6% in Canyon County and 27.5% in Ada County. Our calculation from [1]
More than half of Star's housing units, 52.1% (±6.6 points), were built in 2010 or later, followed by Kuna at 43.1%, Eagle at 42.9% and Meridian at 39.8%, against 13.1% in Boise and 11.4% nationally. Our calculation from [1]
Boise has an estimated 6,661 housing units built in 1939 or earlier, Nampa 2,639 and Caldwell 1,426; in each of the three cities that is about 6% of the housing stock. Source [1]
EPA states that 87% of homes built before 1940, 69% of homes built from 1940 to 1959 and 24% of homes built from 1960 to 1977 are likely to have lead-based paint. These are national figures. Source [3]
EPA's Renovation, Repair and Painting rule covers paid renovations in housing built before 1978. Its only size exemption is for minor work disturbing 6 square feet or less of painted surface per room indoors, or 20 square feet or less outdoors, and that exemption never covers window replacement or demolition. Source [4]
Since April 22, 2010, a firm must be EPA-certified to perform covered renovations, and EPA, not the state, administers the rule in Idaho. Source [4], [5]
OSHA's construction standard requires employers to presume asbestos in thermal system insulation and surfacing material in buildings constructed no later than 1980, and in asphalt and vinyl flooring installed no later than 1980, unless testing shows otherwise. Source [6]
The federal asbestos air-toxics rule excludes residential buildings with four or fewer dwelling units from its definition of a regulated facility, and EPA says federal law does not require accreditation for people who remove asbestos in detached single-family homes, while recommending trained professionals. Source [7], [8]
| Area | Median year built | Housing units | Units built before 1980 | Built before 1980 | Built before 1960 | Built before 1940 | Built 2010 or later |
|---|---|---|---|---|---|---|---|
| Boise | 1986 (±2) | 106,279 | 44,682 | 42.0% (±1.3) | 17.2% (±0.9) | 6.3% (±0.5) | 13.1% (±0.8) |
| Meridian | 2007 (±2) | 49,586 | 3,254 | 6.6% (±0.9) | 1.7% (±0.5) | 0.9% (±0.4) | 39.8% (±1.7) |
| Eagle | 2007 (±2) | 13,550 | 1,710 | 12.6% (±3.3) | 3.4% (±2.5) | 2.5% (±2.4) | 42.9% (±3.5) |
| Nampa | 2000 (±1) | 40,529 | 10,483 | 25.9% (±2.0) | 14.9% (±1.6) | 6.5% (±0.8) | 22.4% (±1.8) |
| Caldwell | 2003 (±2) | 22,378 | 6,524 | 29.2% (±2.7) | 14.9% (±2.1) | 6.4% (±1.2) | 31.8% (±2.7) |
| Kuna | 2008 (±1) | 9,391 | 690 | 7.3% (±2.4) | 4.0% (±2.0) | 2.5% (±1.8) | 43.1% (±4.1) |
| Star | 2011 (±2) | 5,519 | 357 | 6.5% (±4.1) | 2.2% (±1.4) | 1.6% (±1.1) | 52.1% (±6.6) |
| Garden City | 1995 (±2) | 5,916 | 1,489 | 25.2% (±4.4) | 5.0% (±2.7) | 0.8% (±0.7) | 18.7% (±4.1) |
| Ada County | 1997 (±1) | 211,440 | 58,054 | 27.5% (±0.8) | 10.1% (±0.5) | 3.9% (±0.3) | 24.8% (±0.8) |
| Canyon County | 1999 (±1) | 89,135 | 27,265 | 30.6% (±1.4) | 15.0% (±1.0) | 7.0% (±0.6) | 23.6% (±1.1) |
| Idaho | 1991 (±1) | 795,014 | 309,996 | 39.0% (±0.5) | 17.2% (±0.3) | 7.9% (±0.2) | 18.1% (±0.4) |
| United States | 1980 (±1) | 143,775,355 | 71,388,105 | 49.7% | 25.6% | 11.7% | 11.4% |
| Ada + Canyon combined | Not published | 300,575 | 85,319 | 28.4% (±0.7) | 11.5% (±0.5) | 4.8% (±0.3) | 24.4% (±0.6) |
Shares and their margins of error are our arithmetic on Census table B25034, using the Census Bureau's formulas for derived estimates. The combined Ada and Canyon row is a sum of the two county rows, not a Census geography.
The federal ban on lead-containing paint for consumer use applies to paint manufactured after February 27, 1978. The Census Bureau reports year built by decade, so "built before 1980" is the closest available measure. It slightly overstates the pre-1978 count, because it includes homes built in 1978 and 1979.
Housing units include houses, apartments, condominiums and manufactured homes, occupied or vacant. These are counts of units, not of buildings or of single-family houses.
The margins of error matter for the smaller cities. Boise as the oldest and Star as the newest by median year built are safe statements. Star, Meridian and Kuna are statistically tied on pre-1980 share, and Boise, Nampa and Caldwell are tied on pre-1940 share, so this study does not rank within those groups.
- Housing-age figures are from the U.S. Census Bureau's American Community Survey 2020 to 2024 5-year estimates, tables B25034 (Year Structure Built) and B25035 (Median Year Structure Built), taken from the Bureau's published summary files.
- Geographies are the cities of Boise, Meridian, Eagle, Nampa, Caldwell, Kuna, Star and Garden City, Ada County, Canyon County, Idaho and the United States. All 288 cells were cross-checked against data.census.gov with no mismatches.
- Pre-1980, pre-1960, pre-1940 and 2010-or-later counts are sums of the decade bins. Shares are those sums divided by total housing units. Margins of error for sums and shares follow the Census Bureau's approximation formulas and are at the 90% confidence level.
- Lead and asbestos rules are quoted from the Code of Federal Regulations and from EPA and OSHA pages, read on the review date shown.
- Year built is reported by the household or estimated by the Census Bureau, by decade. It does not show whether a specific home contains lead paint or asbestos; only testing does.
- EPA's 87%, 69% and 24% figures are national, not Idaho-specific, and EPA's page does not name the survey they come from.
- The 2020 to 2024 estimates are a five-year average, not a single-year snapshot.
- Small cities have wide margins of error. Star's pre-1980 share is 6.5% plus or minus 4.1 points.
- This page summarizes federal rules. Idaho and local requirements were not reviewed beyond the Idaho DEQ compliance page, and this is not legal advice.
Each reference below is cited for a specific claim on this page. Codes, fees and product specifications change — confirm current requirements with the authority having jurisdiction before relying on them for a project decision.
- [1] ACS 2020–2024 5-year, Table B25034, Year Structure Built (U.S. Census Bureau)
Cited for: Housing units by decade built for all 12 areas. Accessed November 12, 2026.
- [2] ACS 2020–2024 5-year, Table B25035, Median Year Structure Built (U.S. Census Bureau)
Cited for: Median year built. Accessed November 12, 2026.
- [3] Reduce the Risk of Lead Exposure in the Home (U.S. Environmental Protection Agency)
Cited for: Share of homes likely to have lead-based paint, by era. Accessed November 12, 2026.
- [4] 40 CFR Part 745, Subpart E, Residential Property Renovation (Electronic Code of Federal Regulations)
Cited for: Renovation, Repair and Painting rule scope, exemption and firm certification. Accessed November 12, 2026.
- [5] Lead Renovation, Repair and Painting Program (U.S. Environmental Protection Agency)
Cited for: States that run their own program; Idaho is not among them. Accessed November 12, 2026.
- [6] 29 CFR 1926.1101, Asbestos (construction) (Electronic Code of Federal Regulations)
Cited for: Presumed asbestos-containing material in buildings from 1980 or earlier. Accessed November 12, 2026.
- [7] 40 CFR 61.141, Asbestos NESHAP definitions (Electronic Code of Federal Regulations)
Cited for: Exclusion of residential buildings with four or fewer units. Accessed November 12, 2026.
- [8] Protect Your Family from Exposures to Asbestos (U.S. Environmental Protection Agency)
Cited for: Federal accreditation not required in detached single-family homes. Accessed November 12, 2026.
- [9] 16 CFR Part 1303, Ban of Lead-Containing Paint (Electronic Code of Federal Regulations)
Cited for: The February 27, 1978 ban date. Accessed November 12, 2026.
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Iron Crest Remodel. "How Old Is Treasure Valley Housing? Lead Paint and Asbestos Exposure by City." Published November 12, 2026; reviewed November 12, 2026. https://ironcrestremodel.com/research/hazards/treasure-valley-housing-age-lead-asbestos
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