How old are the homes in the Town of Union (Rock County), WI?

Name: Age of homes in the Town of Union (Rock County), WI, 2020–2024
Creator: US Census Bureau
License: https://www.census.gov/data/developers/about/terms-of-service.html

50.3% (±16.8 points) of the homes in the Town of Union (Rock County), WI were built before 1980 (2020–2024 American Community Survey).

20.5% were built before 1940.

1.7% were built in 2010 or later.

Figures last updated on November 12, 2026.

Built before 1980: 50.3% (±16.8 points)
Built before 1940: 20.5%
Built 2010 or later: 1.7%

When the homes in the Town of Union (Rock County) were built

Housing units by year structure built, 2020–2024
Year built	Town of Union (Rock County)	Rock County	Wisconsin	United States
2020 or later	0.0% (±2.5 points)	1.2%	1.4%	2.0%
2010 to 2019	1.7% (±1.7 points)	4.3%	7.1%	9.4%
2000 to 2009	12.8% (±5.4 points)	10.8%	12.5%	13.6%
1990 to 1999	28.6% (±8.5 points)	10.8%	12.5%	12.4%
1980 to 1989	6.6% (±3.0 points)	8.0%	9.5%	12.9%
1970 to 1979	13.2% (±6.4 points)	14.4%	14.2%	14.2%
1960 to 1969	12.5% (±12.9 points)	13.4%	9.4%	9.9%
1950 to 1959	1.7% (±1.8 points)	10.7%	10.3%	9.5%
1940 to 1949	2.4% (±2.1 points)	7.2%	5.3%	4.4%
1939 or earlier	20.5% (±8.1 points)	19.2%	17.8%	11.7%

In the Town of Union (Rock County), the share of homes built before 1980 is not measurably different from Rock County (64.9%).

It is not measurably different from Wisconsin (57.0%).

It is not measurably different from the national figure (49.7%).

In Rock County, the Town of Union (Rock County) ranks 24 of 28 places with a published estimate, from highest to lowest share of homes built before 1980.

Statewide, it ranks 1109 of 1,848.

Rankings use the estimates alone; where margins of error overlap, neighboring ranks may not truly differ.

Why the age of a home matters: lead-based paint

Federal law treats housing built before 1978 as likely to contain lead-based paint.

Before a lease or sale of most pre-1978 housing, the landlord or seller must disclose any known lead-based paint and hazards and give the tenant or buyer the EPA pamphlet (42 U.S.C. § 4852d; 40 CFR part 745, subpart F; 24 CFR part 35, subpart A).

A contractor paid to renovate, repair or paint a pre-1978 home must be a certified firm, use a certified renovator and follow lead-safe work practices under the Renovation, Repair and Painting Rule (40 CFR part 745, subpart E) whenever the job disturbs more than 6 square feet of painted surface in a room or more than 20 square feet outside; window replacement and demolition always count (40 CFR 745.83).

Certification comes from EPA, or from the state where EPA has authorized the state to run the program.

The Census Bureau groups construction by decade, so the share built before 1978 lies between the share built before 1970 (37.1%) and the share built before 1980 (50.3%).

Homes built before 1980 in places near the Town of Union (Rock County)

Nearest places with a published estimate, compared with the Town of Union (Rock County)
Place	Distance	Homes built before 1980	Compared with this place
Town of Union (Rock County)	—	50.3% (±16.8 points)	—
Evansville	2.1 mi	47.5% (±9.7 points)	Not measurably different
Brooklyn	4.5 mi	44.1% (±9.6 points)	Not measurably different
Town of Rutland	5.5 mi	49.2% (±13.5 points)	Not measurably different
Town of Brooklyn (Green County)	6.2 mi	39.4% (±8.9 points)	Not measurably different
Town of Magnolia	6.3 mi	61.5% (±18.4 points)	Not measurably different
Town of Porter	6.7 mi	60.4% (±14.3 points)	Not measurably different
Town of Albany (Green County)	7.9 mi	43.6% (±14.0 points)	Not measurably different
Town of Dunkirk	8.2 mi	65.2% (±9.8 points)	Not measurably different

None of the nearby places differs measurably from this one on this figure.

Distance is measured in a straight line between the Census Bureau’s internal points for each place.

Homes built before 1980 across Rock County, place by place

Rank	Place	Homes built before 1980
18	Janesville	62.7% (±3.3 points)
19	Town of Magnolia	61.5% (±18.4 points)
20	Town of Porter	60.4% (±14.3 points)
21	Milton	56.9% (±10.4 points)
22	Town of Center (Rock County)	54.6% (±11.2 points)
23	Town of Milton (Rock County)	52.7% (±15.7 points)
24	Town of Union (Rock County)	50.3% (±16.8 points)
25	Town of Janesville	48.6% (±15.0 points)
26	Evansville	47.5% (±9.7 points)
27	Town of Harmony (Rock County)	46.0% (±11.1 points)
28	Town of Fulton	40.6% (±12.4 points)

Showing 11 of 28 places in Rock County, ranked from highest to lowest.

Survey years: 2020–2024 (American Community Survey 5-year estimates).

Margins of error are at the 90% confidence level.

What you can do on Seayora in Town of Union (Rock County)

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Questions about Town of Union (Rock County)

How old are most homes in the Town of Union (Rock County)?

50.3% of homes in the Town of Union (Rock County), WI were built before 1980 (2020–2024 American Community Survey).

Do homes in the Town of Union (Rock County) need a lead paint disclosure?

A home built before 1978 does, before it is rented or sold, unless an exemption applies (42 U.S.C. § 4852d); between 37.1% and 50.3% of homes in the Town of Union (Rock County) were built before then.

Does a contractor need lead certification to work on older homes in the Town of Union (Rock County)?

Yes, when the job disturbs more than 6 square feet of paint in a room or 20 square feet outside, or replaces a window: the firm must be certified and a certified renovator must direct the work under the Renovation, Repair and Painting Rule (40 CFR part 745, subpart E).

Sources

Selected Housing Characteristics (DP04), 2020–2024 ACS 5-year estimates — Union town, Rock County, Wisconsin

To check these figures in the Census Bureau’s own API, request the variables below from the 2024 ACS 5-year data profile (acs/acs5/profile) for Union town, Rock County, Wisconsin (county subdivision:81650, in state:55 county:105).

Each estimate (E or PE) has a margin of error beside it (M or PM).

The API needs a free key.

Request a Census API key.

DP04_0017PE, DP04_0017PM, DP04_0018PE, DP04_0018PM, DP04_0019PE, DP04_0019PM, DP04_0020PE, DP04_0020PM, DP04_0021PE, DP04_0021PM, DP04_0022PE, DP04_0022PM, DP04_0023PE, DP04_0023PM, DP04_0024PE, DP04_0024PM, DP04_0025PE, DP04_0025PM, DP04_0026PE, DP04_0026PM

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Figures are published by the US Census Bureau, HUD, the Bureau of Labor Statistics and the FBI; Seayora reproduces them and does not adjust them, except where a sentence says it compares dollar figures after inflation. They describe the whole place, not any one building or street, and are not an appraisal, a rent determination, a tax bill, a safety rating or legal advice.