Permits through August 2026Yearly permits since 1995Williamson County index 1978–2025
Williamson County (100 = first year)United States, rebased to the same startNBER recession
House prices are indexed by county, not by city: this is Williamson 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.
Williamson County Unincorporated Area, Tennessee (Williamson County), authorised 412 housing units through building permits in the 12 months to August 2026, −7.6% on the previous 12 months.
412 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 13,495 units, with the busiest year 1996 (853 units). Williamson County's FHFA house price index rose +128.3% over the ten years to 2025.
412units permitted, 12 months to August 2026−7.6% on the previous 12 months
412single-family units100% of the total
0units in 5+ unit buildings0% of the total
—units per 1,000 residentsWilliamson County 6.6 · Tennessee 5.7
Permits by month and structure type
Housing units authorised in Williamson County Unincorporated Area by month, latest 24 monthssingle-family2+ unit buildings
Units, 12 months to August 2026
Williamson County Unincorporated Area
Williamson County
Tennessee
United States
All housing units
412
1,792
41,556
1,418,086
Single-family (1 unit)
412 (100%)
1,286 (72%)
30,956 (74%)
888,241 (63%)
2 units
0
0
508
34,814
3–4 units
0
15
481
17,298
5 or more units
0 (0%)
491 (27%)
9,611 (23%)
477,733 (34%)
Units per 1,000 residents
—
6.6
5.7
4.1
Change on previous 12 months
−7.6%
+30.0%
−4.5%
−0.1%
Permits by year since 1995
Housing units authorised in Williamson County Unincorporated Area by year, 1995–2025single-family2+ unit buildings
13,495 units since 1995; the busiest year was 1996. Annual figures include units imputed for months a place did not report.
Home prices in Williamson County
FHFA's index for Williamson County rose +128.3% over the ten years to 2025 (+8.6% a year) and +2.8% in the latest year, against +113.5% and +2.4% for Tennessee. 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 Williamson County Unincorporated Area, TN?
412 housing units were authorised by building permits in the 12 months to August 2026, against 446 in the previous 12 months.
What kind of housing is being permitted in Williamson County Unincorporated Area?
412 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 Williamson 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; Williamson County runs at 6.6 units per 1,000 residents and Tennessee at 5.7.
How have home prices moved in Williamson County?
FHFA's index for Williamson County rose +128.3% over the ten years to 2025 and +2.8% 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 907000); 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.