Cedar Point, NC
3 miles east
Median home built 2000 (Swansboro: 2002); Its NOAA station logs about 290 more heating degree days than Swansboro's
Attic insulation in Cedar PointAttic Insulation in Swansboro, NC
Blown-in attic insulation for Swansboro, NC, in Onslow County, plus removal and air sealing.
About Swansboro and Its Homes
Swansboro was laid out in the early 1770s at the mouth of the White Oak River and recognized by the General Assembly in 1783. Most of the old houses in its historic district are frame homes from the lumber boom of roughly 1880 to 1925, trimmed with moldings cut at the town's own sawmills.
Swansboro, in Onslow County, grew from 3,754 people in 2020 to 4,174 in 2025 (Census Bureau estimates), on 2.23 square miles. That makes Swansboro the third-largest town in Onslow County.
Swansboro has about 1,850 housing units, 2 percent of Onslow County's.
Swansboro at a Glance
- County: Onslow County
- Population: 4,174 (2025), 3,754 (2020), up 11.2%
- Land area: 2.23 square miles (1,872 people each)
- Housing units: about 1,850 (±208)
- Median year built: 2002 (±5); Onslow County: 1998
- Owner-occupied: 72% (±14); Onslow County: 64%
- Detached houses: 78% (±8); Onslow County: 65%
- Attached houses: 7% (±5)
- Apartments: 13% (±7)
- Mobile homes: under 7%
- Climate zone: 3 on both maps
- ENERGY STAR target for Swansboro attics: R-49 from bare, R-38 over 3 to 4 inches (R-value guide)
Census Bureau estimates for Swansboro, 2020 to 2024 (± margin of error).
Swansboro Homes and Their Attics
Lumber Boom Houses Along the White Oak
The Swansboro Historic District, listed in 1990, has a nomination that names the I-house as the main type of the lumber years: two stories, one room deep, with a symmetrical three-bay front. Gable-fronted side-hall houses and one-story houses with two-room or center-hall plans fill out the streets, many with beaded tongue-and-groove walls and ceilings inside. Nearly all were built between the late 1880s and 1925. Some of these houses may still run on their first wiring, porcelain knobs and tubes strung across the attic joists. ENERGY STAR flags that kind of wiring as dangerous once insulation buries it. Have an electrician look at it and fix it before anything is blown in over the ceilings.
Attic Insulation in Swansboro
If the joists show above the insulation in a Swansboro attic, ENERGY STAR says to add more insulation.
In 2010 or later, about 35 percent of Swansboro homes went up; check their air sealing as well as the depth.
The Local Climate
Swansboro's center sits about 20 feet above sea level, 15 miles from NOAA's New River Marine Corps Air Facility station, the best match for Swansboro. The station's 1991 to 2020 normals average about 2,500 heating and 2,020 cooling degree days a year, so Swansboro attics work in both seasons.
Readings change over short distances around Swansboro: NOAA's Newport/Morehead City Weather Office station, 15 miles away, averages about 2,780 heating degree days. The state energy code marks Onslow County warm and humid.
Homes by Age: What It Means for the Attic
About 78 percent of Swansboro housing units are detached single-family houses.
From 1990 to 2009, about 30 percent of Swansboro homes were built to codes below ENERGY STAR's target; check their eaves, where ENERGY STAR says insulation is often thinnest.
Homes by Year Built
- Before 1940: under 1%
- 1940s: under 25%, about 230 units
- 1950s: 9% (±8), about 170 units
- 1960s: under 4%, about 30 units
- 1970s: 7% (±5), about 125 units
- 1980s: 4% (±3), about 85 units
- 1990s: 11% (±6), about 210 units
- 2000s: 21% (±9), about 380 units
- 2010s: 29% (±10), about 530 units
- 2020 or later: 5% (±5), about 95 units
Air Sealing and Duct Sealing in Swansboro
In Swansboro, 96 percent of homes heat with electricity; where that heat is forced air, ducts often run through the attic.
Air sealing comes first, as the EPA advises: wire and pipe holes, wall tops and soffits.
How Homes Here Are Heated
- Electricity: 96% (±5), about 1,610 households; Onslow County: 92%
- Bottled or tank gas: under 6%, about 50 households
Power, Gas and Rebates
Duke Energy Progress serves most of Swansboro, Jones-Onslow EMC and Carteret-Craven Electric Cooperative its edges; your bill says which. For gas, Swansboro is in the Onslow County franchise of Piedmont Natural Gas, whose mains may not reach every street in Swansboro. Duke's free House Call fits many Swansboro homes: 96 percent heat with electricity.
Rebate to check in Swansboro: Smart $aver Insulate and Seal (Duke Energy; Insulation Pros is an approved trade ally). Before a job in Swansboro, check its current terms; the Onslow County page lists every program.
Attic Insulation Removal in Swansboro
In a Swansboro attic, only wet, moldy or animal-soiled insulation is vacuumed out (ENERGY STAR's test), once the cause is fixed, and after mice that Swansboro attic is sanitized and deodorized; dry, clean insulation stays.
Also Serving Near Swansboro
Nearest to Swansboro first.
Peletier, NC
4 miles northeast
Median home built 1995 (Swansboro: 2002); 803 people, about a fifth of Swansboro's population
Attic insulation in PeletierBogue, NC
6 miles east
Median home built 1998 (Swansboro: 2002); 706 people, about a sixth of Swansboro's population
Attic insulation in BogueEmerald Isle, NC
6 miles east
Median home built 1989 (Swansboro: 2002)
Attic insulation in Emerald Isle
Swansboro Insulation FAQs
Does the Historic Preservation Commission have to approve insulating my Swansboro attic?
Not the insulation work. Swansboro's town council created its local historic district in 1985 or 1986, and outside changes there go through the town's Historic Preservation Design Standards and a certificate of appropriateness. State law keeps a commission's review to the exterior, not the arrangement inside. Blowing in insulation and sealing the attic floor are inside work. Cutting in a ridge vent or new soffit vents is exterior work, and that part waits for the town's approval. The local district's edges are not the same as the National Register district's, so check its map too.
Should the louvered vents in the gables of my old house be closed up?
No. The district's nomination lists louvered gable vents among the details of Swansboro's turn-of-the-century houses, and where they open into the attic they let its air out. In ENERGY STAR's picture of a vented attic, outside air enters at the soffits and leaves up top, through a ridge vent or gable vents. Blocking that path traps summer heat and moisture up there. We keep insulation clear of the vents, and baffles hold a channel open at the eaves. Changing the vents themselves in the local district is outside work for the town to approve.
Does attic insulation in Swansboro need a permit?
Swansboro Town Hall can say whether Onslow County Building Guides, the town itself or another office handles permits in Swansboro; ask before work starts.
Helpful Guides
- Onslow County is warm and humid by the state energy code: attic condensation and mold
- Median home built 2002: a hot upstairs and bonus rooms over garages
- Power from Duke Energy Progress: high summer electric bills
Sources
Census Bureau figures for Swansboro, NOAA normals for the New River Marine Corps Air Facility station, Duke Energy Progress (October 2026). Compiled by Insulation Pros. How the town pages are made.
Sources for the Swansboro notes and questions (read October 20, 2026):
- Swansboro, in The North Carolina Gazetteer (William S. Powell, 2nd ed., UNC Press 2010), NCpedia
- Swansboro Historic District, National Register nomination (NC HPO)
- Historic and Architectural Resources of Onslow County, North Carolina, National Register multiple property documentation form (NC HPO)
- Attic Insulation Project, ENERGY STAR
- Town of Swansboro Architectural Survey Update, final report, 2022 (Richard Grubb and Associates for the Town of Swansboro, filed with the NC HPO)
- N.C. Gen. Stat. 160D-947, Certificate of appropriateness required
- About Attic Ventilation, ENERGY STAR do-it-yourself guide
Swansboro, NC
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Insulation Pros is an insulation contractor serving North Carolina, Swansboro and the rest of Onslow County included.
Reach us
Send the square footage of your Swansboro attic, or call (336) 870-3893.