Permits through August 2026Yearly permits since 1995Jefferson County index 1991–2025
Jefferson County (100 = first year)United States, rebased to the same startNBER recession
House prices are indexed by county, not by city: this is Jefferson County's FHFA index, with the national index rebased to the same start.
Census Bureau notes: building permit figures cover new privately owned housing units authorised by permit-issuing places; permits do not mean the units were started or completed, and places that report less often than monthly are imputed in monthly totals. FHFA notes: The FHFA HPI is a broad measure of the movement of single-family house prices. The FHFA HPI is a weighted, repeat-sales index, meaning that it measures average price changes in repeat sales or refinancings on the same properties.
Jefferson County Unincorporated Area, Idaho (Jefferson County), authorised 299 housing units through building permits in the 12 months to August 2026, +9.5% on the previous 12 months.
299 of those units were single-family houses (100%), 0 were in two- to four-unit buildings and 0 in buildings of five or more units.
Since 1995 the place has authorised 5,341 units, with the busiest year 2021 (363 units). Jefferson County's FHFA house price index rose +145.6% over the ten years to 2025.
299units permitted, 12 months to August 2026+9.5% on the previous 12 months
299single-family units100% of the total
0units in 5+ unit buildings0% of the total
—units per 1,000 residentsJefferson County 8.8 · Idaho 9.1
Permits by month and structure type
Housing units authorised in Jefferson County Unincorporated Area by month, latest 24 monthssingle-family2+ unit buildings
Units, 12 months to August 2026
Jefferson County Unincorporated Area
Jefferson County
Idaho
United States
All housing units
299
309
18,471
1,418,086
Single-family (1 unit)
299 (100%)
299 (97%)
14,341 (78%)
888,241 (63%)
2 units
0
0
316
34,814
3–4 units
0
0
664
17,298
5 or more units
0 (0%)
10 (3%)
3,150 (17%)
477,733 (34%)
Units per 1,000 residents
—
8.8
9.1
4.1
Change on previous 12 months
+9.5%
+12.8%
+1.3%
−0.1%
Permits by year since 1995
Housing units authorised in Jefferson County Unincorporated Area by year, 1995–2025single-family2+ unit buildings
5,341 units since 1995; the busiest year was 2021. Annual figures include units imputed for months a place did not report.
Home prices in Jefferson County
FHFA's index for Jefferson County rose +145.6% over the ten years to 2025 (+9.4% a year) and +6.4% in the latest year, against +149.0% and +2.3% for Idaho. Full county page: decade table, peak-to-low declines, every ZIP code and every permit-issuing place in the county.
Questions and answers
How many homes are being built in Jefferson County Unincorporated Area, ID?
299 housing units were authorised by building permits in the 12 months to August 2026, against 273 in the previous 12 months.
What kind of housing is being permitted in Jefferson County Unincorporated Area?
299 single-family units, 0 in two-unit buildings, 0 in three- and four-unit buildings and 0 in buildings of five or more units.
How does Jefferson County Unincorporated Area compare with its county and state?
No population estimate is attached to this permit-issuing area, so a per-resident rate is not shown; Jefferson County runs at 8.8 units per 1,000 residents and Idaho at 9.1.
How have home prices moved in Jefferson County?
FHFA's index for Jefferson County rose +145.6% over the ten years to 2025 and +6.4% in the latest year; the county page has the full series.
What does a permit count?
A housing unit authorised by a building permit for new privately owned residential construction, as reported to the Census Bureau Building Permits Survey by the permit-issuing office. Permits are not completions; some permitted units are never built, and places that report only annually are imputed in monthly figures.
Provenance
Permits: US Census Bureau, Building Permits Survey, place-level monthly and annual files through August 2026 (permit office 469000); county and state comparisons from the county and state files. Population: Census Bureau vintage 2025 estimates for incorporated places, matched on FIPS place code where the permit office is one. House price index: Federal Housing Finance Agency. Public domain. Corrections · Building Permits Survey.