How old are the homes in Knowlton Township, NJ?

Name: Age of homes in Knowlton Township, NJ, 2020–2024
Creator: US Census Bureau
License: https://www.census.gov/data/developers/about/terms-of-service.html

52.8% (±9.7 points) of the homes in Knowlton Township, NJ were built before 1980 (2020–2024 American Community Survey).

27.3% were built before 1940.

1.8% were built in 2010 or later.

Figures last updated on November 12, 2026.

Built before 1980: 52.8% (±9.7 points)
Built before 1940: 27.3%
Built 2010 or later: 1.8%

When the homes in Knowlton Township were built

Housing units by year structure built, 2020–2024
Year built	Knowlton Township	Warren County	New Jersey	United States
2020 or later	0.7% (±1.0 points)	0.6%	1.1%	2.0%
2010 to 2019	1.1% (±1.2 points)	3.2%	6.2%	9.4%
2000 to 2009	6.8% (±3.2 points)	11.7%	9.2%	13.6%
1990 to 1999	20.1% (±9.6 points)	11.7%	8.9%	12.4%
1980 to 1989	18.6% (±4.4 points)	12.6%	11.8%	12.9%
1970 to 1979	14.3% (±4.6 points)	13.4%	12.3%	14.2%
1960 to 1969	2.2% (±1.6 points)	9.2%	12.8%	9.9%
1950 to 1959	6.9% (±3.2 points)	9.0%	13.8%	9.5%
1940 to 1949	2.1% (±1.3 points)	5.1%	6.5%	4.4%
1939 or earlier	27.3% (±7.7 points)	23.6%	17.4%	11.7%

In Knowlton Township, the share of homes built before 1980 is not measurably different from Warren County (60.3%).

It is also lower than in New Jersey (62.8%).

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

In Warren County, Knowlton Township ranks 13 of 22 places with a published estimate, from highest to lowest share of homes built before 1980.

Statewide, it ranks 439 of 564.

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 (38.5%) and the share built before 1980 (52.8%).

Homes built before 1980 in places near Knowlton Township

Nearest places with a published estimate, compared with Knowlton Township
Place	Distance	Homes built before 1980	Compared with this place
Knowlton Township	—	52.8% (±9.7 points)	—
Portland	2.0 mi	84.2% (±17.5 points)	Higher
Upper Mount Bethel Township	4.3 mi	52.5% (±10.0 points)	Not measurably different
Delaware Water Gap	4.6 mi	77.1% (±18.4 points)	Higher
Hope Township	4.7 mi	62.3% (±13.7 points)	Not measurably different
Blairstown Township	4.9 mi	61.5% (±14.5 points)	Not measurably different
Belvidere Town	6.9 mi	88.7% (±14.1 points)	Higher
East Bangor	7.3 mi	71.5% (±13.2 points)	Higher
Smithfield Township (Monroe County)	7.4 mi	35.6% (±6.9 points)	Lower

Nearby places with a measurably lower figure: Smithfield Township (Monroe County), PA (35.6%).

Nearby places with a measurably higher figure: Portland, PA (84.2%), Delaware Water Gap, PA (77.1%), Belvidere Town, NJ (88.7%).

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

Homes built before 1980 across Warren County, place by place

Rank	Place	Homes built before 1980
7	Hackettstown Town	67.8% (±8.2 points)
8	Oxford Township	66.4% (±12.3 points)
9	Hope Township	62.3% (±13.7 points)
10	Blairstown Township	61.5% (±14.5 points)
11	Liberty Township	58.5% (±11.2 points)
12	Washington Township (Warren County)	56.4% (±11.7 points)
13	Knowlton Township	52.8% (±9.7 points)
14	Hardwick Township	50.3% (±10.3 points)
15	Lopatcong Township	50.0% (±9.7 points)
16	Franklin Township (Warren County)	49.8% (±10.0 points)
17	Mansfield Township (Warren County)	47.7% (±10.1 points)
18	Allamuchy Township	44.5% (±9.3 points)
19	Frelinghuysen Township	43.5% (±7.6 points)

Showing 13 of 22 places in Warren 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.

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Questions about Knowlton Township

How old are most homes in Knowlton Township?

52.8% of homes in Knowlton Township, NJ were built before 1980 (2020–2024 American Community Survey).

Do homes in Knowlton Township 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 38.5% and 52.8% of homes in Knowlton Township were built before then.

Does a contractor need lead certification to work on older homes in Knowlton Township?

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 — Knowlton township, Warren County, New Jersey

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 Knowlton township, Warren County, New Jersey (county subdivision:37320, in state:34 county:041).

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.