Attic Insulation in Onslow County, NC

Onslow County and Its Homes

Onslow County grew 6 percent from 2020 to 2025, to 217,175 people by the Census Bureau's estimate, in about 87,400 housing units.

Its five incorporated towns each have a page here: Jacksonville, Holly Ridge, Swansboro, Richlands and North Topsail Beach. About 40 percent of Onslow County's housing units are inside town limits, the rest in unincorporated areas.

A brick courthouse with a white cupola and flags in Jacksonville, North Carolina — The Onslow County Courthouse in Jacksonville, the county seat Photo: Indy beetle, CC0, via Wikimedia Commons

Onslow County at a Glance

Population: 217,175 (2025), 204,984 (2020)
Housing units: about 87,400
Median year built: 1998 (North Carolina: 1991)
Built before 1980: 26% (statewide: 34%)
Detached houses: 65%
Mobile homes: 12%
Owner-occupied: 64%
Heated with electricity: 92% (statewide: 65%)
Climate zone: 3 on both maps, warm-humid
Towns with pages here: 5

Census Bureau estimates for Onslow County (housing: 2020 to 2024).

Towns and Communities in Onslow County

Jacksonville
72,732 people · median home 1992 · Duke Energy Progress
Holly Ridge
5,908 people · median home 2015 · Duke Energy Progress
Swansboro
4,174 people · median home 2002 · Duke Energy Progress
Richlands
2,485 people · Duke Energy Progress
North Topsail Beach
1,097 people · median home 1989 · power varies by address
Surf City
Pender County town · about 430 residents in Onslow County

Unincorporated communities the Census Bureau maps in Onslow County: Piney Green (about 6,000 housing units, median year built 1994), Half Moon (about 3,100 housing units, median year built 1988), Sneads Ferry (about 2,000 housing units, median year built 1986) and Pumpkin Center (median year built 1986).

What We Do in Onslow County

Attic Insulation in Onslow County
Some 26 percent of Onslow County housing units predate 1980; joists showing above their insulation mean more blown-in fiberglass is due, R-49 from bare.
Attic Insulation Removal in Onslow County
Wet, moldy or animal-soiled insulation comes out of Onslow County attics, and a mouse-soiled Onslow County attic is sanitized and deodorized; in the 8 percent of homes built before 1960, vermiculite is ruled out first.
Air Sealing in Onslow County
Some 92 percent of Onslow County homes heat with electricity, often through attic ducts; their joints and the ceiling's gaps are sealed first.

Homes in Onslow County

Half of Onslow County's 87,400 housing units were built before 1998: 15 percent before 1970, 26 percent before 1980 (nearly all before the state's 1978 insulation rule) and 27 percent in 2010 or later. The largest share went up in the 2010s; in attics that new, check the air sealing as well as the depth. Among Onslow County towns, the median home is oldest in North Topsail Beach (1989) and newest in Holly Ridge (2015).

Onslow County by type: 65 percent detached houses, 13 percent in buildings of two or more homes and 12 percent mobile homes. In Onslow County, 92 percent of homes heat with electricity, 4 percent with piped gas and 3 percent with tank gas.

Onslow County Homes by Year Built

Before 1940: about 460 units, 1% (±1)
1940s: about 1,730 units, 2% (±1)
1950s: about 4,780 units, 5% (±1)
1960s: about 6,000 units, 7% (±1)
1970s: about 9,360 units, 11% (±1)
1980s: about 11,530 units, 13% (±1)
1990s: about 11,870 units, 14% (±1)
2000s: about 18,020 units, 21% (±2)
2010s: about 20,120 units, 23% (±2)
2020 or later: about 3,490 units, 4% (±1)

Climate Across Onslow County

The state energy code marks Onslow County warm and humid.

NOAA 1991 to 2020 normals for Onslow County towns, by station: Surf City station (Holly Ridge and North Topsail Beach): about 2,770 heating and 1,740 cooling degree days; Jacksonville EOC station (Jacksonville): about 2,770 heating and 1,880 cooling degree days; New River Marine Corps Air Facility station (Swansboro): about 2,500 heating and 2,020 cooling degree days; Richlands station (Richlands): about 3,080 heating and 1,630 cooling degree days.

Power and Gas in Onslow County

The card lists Onslow County's town utilities by the territory maps; a power bill confirms the one at an address.

Piedmont Natural Gas holds the Onslow County gas franchise (NC Utilities Commission map), and 4 percent of Onslow County homes heat with piped gas.

Who Supplies Power in Onslow County

Duke Energy Progress: Jacksonville, Holly Ridge, Swansboro and Richlands; parts of North Topsail Beach
Jones-Onslow EMC: parts of North Topsail Beach; homes near Jacksonville, Holly Ridge, Swansboro and Richlands
Carteret-Craven Electric Cooperative: homes near Swansboro

Energy Programs for Onslow County Homes

Check each program's current terms for an Onslow County home; some pay only through the utility's contractor network. Insulation Pros is an approved Duke Energy trade ally for Duke's rebate.

Programs for Onslow County

Smart $aver Insulate and Seal (Duke Energy rebate; Jacksonville, Holly Ridge, Swansboro, Richlands and more).
Home Energy House Call (Duke Energy home assessment; Jacksonville, Holly Ridge, Swansboro, Richlands and more).
Online Energy Audit (Jones-Onslow EMC; North Topsail Beach, near Jacksonville, near Holly Ridge, near Swansboro and more): an online energy audit tool for members.
Income-qualified Weatherization (Duke Energy income-qualified; Jacksonville, Holly Ridge, Swansboro, Richlands and more).
Energy Saver North Carolina (statewide income-qualified; any Onslow County address).
Weatherization Assistance Program (statewide income-qualified; any Onslow County address).
Piedmont Natural Gas lists rebates for high-efficiency gas furnaces, and none for insulation or air sealing (program page).

Get Your Free Estimate

or call (336) 870-3893

Onslow County Insulation FAQs

Do you serve all of Onslow County?

Yes: Jacksonville, Holly Ridge, Swansboro, Richlands and North Topsail Beach, the parts of Surf City inside Onslow County, and every unincorporated Onslow County address.

Which utilities offer insulation rebates in Onslow County?

Duke Energy's Smart $aver Insulate and Seal (Jacksonville, Holly Ridge, Swansboro, Richlands and more).

Does attic insulation in Onslow County need a permit?

Ask Onslow County Building Guides before work starts. For an address in Jacksonville, Holly Ridge, Swansboro or another Onslow County town, the town or city hall can tell you whether Onslow County's office handles its permits.