Attic Insulation in Princeton, NC
Blown-in attic insulation for Princeton, NC, 6 miles from Pine Level, plus removal and air sealing.
About Princeton and Its Homes
Princeton grew up in the 1850s around a North Carolina Railroad depot built on Wiley Hastings's land, was incorporated as Boon Hill in 1861 and took its present name in 1873. A 1983 nomination describes Hastings's own house of about 1845 as a story-and-a-half frame home with bedrooms tucked under its roof.
Princeton, in Johnston County, grew from 1,322 people in 2020 to 1,544 in 2025 (Census Bureau estimates), on 1.17 square miles.
Princeton has about 780 housing units, 1 percent of Johnston County's; about 50 percent of the town's households own their home.
Princeton at a Glance
- County: Johnston County
- Population: 1,544 (2025), 1,322 (2020), up 16.8%
- Land area: 1.17 square miles (1,320 people each)
- Housing units: about 780 (±186)
- Median year built: 1977 (±4); Johnston County: 2000
- Owner-occupied: 50% (±7); Johnston County: 76%
- Attached houses: 5% (±5)
- Apartments: 19% (±11)
- Mobile homes: under 25%
- Climate zone: 3 on both maps
- ENERGY STAR target for Princeton attics: R-49 from bare, R-38 over 3 to 4 inches (R-value guide)
Census Bureau estimates for Princeton, 2020 to 2024 (± margin of error).
Princeton Homes and Their Attics
Knee Walls in a Story-and-a-Half House of the 1840s
The Hastings-McKinnie House stands at the southeastern edge of town, on the tract where Hastings laid out much of the town's street plan. Its 1983 National Register nomination describes a frame house of one and a half stories under a gable roof, with an upstairs hall and two bedrooms that all have knee walls. In a house built this way, the upper rooms sit partly inside the roof. The narrow wedges of attic behind those short walls, and the floor spaces under them, are common air leaks. They get sealed and insulated along with the main attic, or the upstairs stays hard to heat and cool.
Attic Insulation in Princeton
About 35 percent of Princeton's homes predate 1970; if your joists show above the insulation, ENERGY STAR says to add more insulation.
The Local Climate
Princeton's center sits about 150 feet above sea level, 11 miles from NOAA's Smithfield station, the best match for Princeton. The station's 1991 to 2020 normals average about 3,080 heating and 1,870 cooling degree days a year, so at Princeton's station, heating needs outweigh cooling.
Homes by Age: What It Means for the Attic
Built from 1940 to 1969, about 30 percent of Princeton homes often have little insulation. From 1990 to 2009, about 15 percent of Princeton homes were built to codes below ENERGY STAR's target; check their eaves, where ENERGY STAR says insulation is often thinnest.
About 55 percent of Princeton's housing units predate 1980; nearly all predate the state's 1978 insulation rule too.
Homes by Year Built
- Before 1940: 8% (±5), about 65 units
- 1940s: 13% (±6), about 105 units
- 1950s: 6% (±4), about 50 units
- 1960s: 8% (±4), about 65 units
- 1970s: 20% (±11), about 160 units
- 1980s: 14% (±13), about 110 units
- 1990s: 7% (±5), about 60 units
- 2000s: 10% (±5), about 80 units
- 2010s: 9% (±5), about 70 units
- 2020 or later: 3% (±2), about 20 units
Air Sealing and Duct Sealing in Princeton
In Pine Level, the nearest town to Princeton with solid figures, about 90 percent of homes heat with electricity.
Air sealing comes first, as the EPA advises: wire and pipe holes, wall tops and soffits.
How Homes Here Are Heated
- Electricity: 79% (±14), about 530 households; Johnston County: 78%
- Piped gas: 4% (±4), about 25 households
- Bottled or tank gas: 17% (±7), about 115 households
Power, Gas and Rebates
Duke Energy Progress supplies Princeton's electricity. For gas, Princeton is in the Johnston County franchise of Piedmont Natural Gas, whose mains may not reach every street in Princeton. Bottled or tank gas, bought by the delivery, heats about 17 percent of homes in Princeton.
Rebate to check in Princeton: Smart $aver Insulate and Seal (Duke Energy; Insulation Pros is an approved trade ally). Before a job in Princeton, check its current terms; the Johnston County page lists every program.
Attic Insulation Removal in Princeton
In a Princeton attic, only wet, moldy or animal-soiled insulation is vacuumed out (ENERGY STAR's test), once the cause is fixed, and after mice that Princeton attic is sanitized and deodorized; dry, clean insulation stays.
Also Serving Near Princeton
Nearest to Princeton first.
Micro, NC
7 miles north
537 people, about a third of Princeton's population
Attic insulation in MicroSelma, NC
9 miles northwest
Power from its own town system (Princeton: Duke Energy Progress); 7,406 people, about 5 times Princeton's population
Attic insulation in SelmaPikeville, NC
10 miles east
Median home built 1974 (Princeton: 1977); 738 people, about half of Princeton's population
Attic insulation in Pikeville
Princeton Insulation FAQs
Do the National Register listings in Princeton restrict work on nearby houses?
No. The town has three individual listings, the Hastings-McKinnie House, the old graded school and the Wood-Rains Cotton Gin, and no listed district. In the preservation office's words, being on the National Register leaves an owner who spends private money free to maintain or change the property, even one of the listed buildings. Johnston County's local commissions on the 2023 state roster are Benson's and Smithfield's. And sealing and insulating an attic is work done from inside.
My Princeton house dates from the early 1900s. Who checks the wiring first?
An electrician, before any insulation goes in. Power came to town in 1915, the cotton gin's nomination notes, in the years when merchants were trading wooden storefronts for brick. Wiring put in around then can include knob-and-tube. ENERGY STAR lists it among the conditions to correct first, since insulation in contact with it is a fire risk. Until that is done, the area around live wiring of that kind is left uncovered.
Could the old insulation in a Princeton attic be vermiculite?
It could: about 30 percent of Princeton's homes predate 1960. If a Princeton attic holds a pebble-like gray-brown or silver-gold fill, leave it undisturbed: the EPA says vermiculite may contain asbestos.
Does attic insulation in Princeton need a permit?
Princeton Town Hall can say whether Johnston County Building Inspections Department, the town itself or another office handles permits in Princeton; ask before work starts.
Helpful Guides
- Power from Duke Energy Progress: high summer electric bills and home energy audits
Sources
Census Bureau figures for Princeton, NOAA normals for the Smithfield station, Duke Energy Progress (October 2026). Compiled by Insulation Pros. How the town pages are made.
Sources for the Princeton notes and questions (read October 20, 2026):
- Hastings-McKinnie House, National Register nomination (NC HPO)
- Princeton, in The North Carolina Gazetteer (William S. Powell, 2nd ed., UNC Press 2010), NCpedia
- Attic Air Sealing Project, ENERGY STAR
- Building Construction Problem Areas, weatherization training text, Iowa Department of Health and Human Services
- NC Listings in the National Register of Historic Places, NC State Historic Preservation Office
- What Is the National Register of Historic Places?, NC State Historic Preservation Office
- Historic Preservation Commission Staff in North Carolina, listed by county, as of 2/20/2023 (NC HPO)
- Wood-Rains Cotton Gin, National Register nomination (NC HPO, listed 2023)
- Attic Insulation Project, ENERGY STAR
Princeton, NC
Open in Google Maps (opens in a new tab)Serving Princeton, NC
Insulation Pros is an insulation contractor serving North Carolina, Princeton and the rest of Johnston County included.
Reach us
Send the square footage of your Princeton attic, or call (336) 870-3893.