Permits through August 2026Yearly permits since 1995Rock County index 1975–2025
Rock County (100 = first year)United States, rebased to the same startNBER recession
House prices are indexed by county, not by city: this is Rock 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.
In the 12 months to August 2026, building permits in Janesville, Wisconsin, covered 133 housing units (+84.7% year on year); the place lies in Rock County.
97 of those units were single-family houses (73%), 28 were in two- to four-unit buildings and 8 in buildings of five or more units. That is 2.0 units per 1,000 residents, below the county's 2.5 and well below the state's 4.3.
Since 1995 the place has authorised 7,029 units, with the busiest year 1995 (522 units). Rock County's FHFA house price index rose +115.5% over the ten years to 2025.
133units permitted, 12 months to August 2026+84.7% on the previous 12 months
97single-family units73% of the total
8units in 5+ unit buildings6% of the total
2.0units per 1,000 residentsRock County 2.5 · Wisconsin 4.3
Permits by month and structure type
Housing units authorised in Janesville by month, latest 24 monthssingle-family2+ unit buildings
Units, 12 months to August 2026
Janesville
Rock County
Wisconsin
United States
All housing units
133
413
25,771
1,418,086
Single-family (1 unit)
97 (73%)
339 (82%)
13,316 (52%)
888,241 (63%)
2 units
16
38
1,306
34,814
3–4 units
12
12
42
17,298
5 or more units
8 (6%)
24 (6%)
11,107 (43%)
477,733 (34%)
Units per 1,000 residents
2.0
2.5
4.3
4.1
Change on previous 12 months
+84.7%
+16.3%
+5.6%
−0.1%
Permits by year since 1995
Housing units authorised in Janesville by year, 1995–2025single-family2+ unit buildings
7,029 units since 1995; the busiest year was 1995. Annual figures include units imputed for months a place did not report.
Home prices in Rock County
FHFA's index for Rock County rose +115.5% over the ten years to 2025 (+8.0% a year) and +5.1% in the latest year, against +95.5% and +5.4% for Wisconsin. 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 Janesville, WI?
133 housing units were authorised by building permits in the 12 months to August 2026, against 72 in the previous 12 months.
What kind of housing is being permitted in Janesville?
97 single-family units, 16 in two-unit buildings, 12 in three- and four-unit buildings and 8 in buildings of five or more units.
How does Janesville compare with its county and state?
2.0 units per 1,000 residents in Janesville, 2.5 in Rock County and 4.3 in Wisconsin.
How have home prices moved in Rock County?
FHFA's index for Rock County rose +115.5% over the ten years to 2025 and +5.1% 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 424500); 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.