Attic Insulation in Johnston County, NC

Johnston County and Its Homes

Johnston County grew 18 percent from 2020 to 2025, to 256,448 people by the Census Bureau's estimate, in about 91,200 housing units.

Its eleven incorporated towns each have a page here: Clayton, Smithfield, Selma, Archer Lodge, Benson, Wilson's Mills, Four Oaks, Pine Level, Kenly, Princeton and Micro. About 30 percent of Johnston County's housing units are inside town limits, the rest in unincorporated areas.

A neoclassical stone courthouse with a row of columns in Smithfield, North Carolina — The Johnston County Courthouse in Smithfield, the county seat Photo: Ammodramus, CC0, via Wikimedia Commons

Johnston County at a Glance

Population: 256,448 (2025), 217,450 (2020)
Housing units: about 91,200
Median year built: 2000 (North Carolina: 1991)
Built before 1980: 22% (statewide: 34%)
Detached houses: 76%
Mobile homes: 13%
Owner-occupied: 76%
Heated with electricity: 78% (statewide: 65%)
Climate zone: 3 on both maps
Towns with pages here: 11

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

Towns in Johnston County

Clayton
32,633 people · median home 2006 · its own electric system
Smithfield
13,114 people · median home 1973 · its own electric system
Selma
7,406 people · its own electric system
Archer Lodge
5,649 people · median home 1996 · Duke Energy Progress
Benson
4,660 people · its own electric system
Wilson's Mills
2,987 people · median home 1997 · Duke Energy Progress
Four Oaks
2,978 people · median home 1985 · Duke Energy Progress
Pine Level
2,405 people · Duke Energy Progress
Kenly
1,722 people · median home 1973 · Duke Energy Progress
Princeton
1,544 people · median home 1977 · Duke Energy Progress
Micro
537 people · Duke Energy Progress

What We Do in Johnston County

Attic Insulation in Johnston County
Some 22 percent of Johnston 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 Johnston County
Wet, moldy or animal-soiled insulation comes out of Johnston County attics, and a mouse-soiled Johnston County attic is sanitized and deodorized; in the 10 percent of homes built before 1960, vermiculite is ruled out first.
Air Sealing in Johnston County
Some 78 percent of Johnston County homes heat with electricity, often through attic ducts; their joints and the ceiling's gaps are sealed first.

Homes in Johnston County

Half of Johnston County's 91,200 housing units were built before 2000: 15 percent before 1970, 22 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 2000s, under codes that asked for less than ENERGY STAR now suggests; ENERGY STAR notes insulation is often thinnest at the eaves. Among Johnston County towns, the median home is oldest in Kenly (1973) and newest in Clayton (2006).

Johnston County by type: 76 percent detached houses, 8 percent in buildings of two or more homes and 13 percent mobile homes. In Johnston County, 78 percent of homes heat with electricity, 12 percent with piped gas (24 percent statewide) and 8 percent with tank gas.

Johnston County Homes by Year Built

Before 1940: about 3,720 units, 4% (±1)
1940s: about 1,640 units, 2% (±1)
1950s: about 3,780 units, 4% (±1)
1960s: about 4,260 units, 5% (±1)
1970s: about 6,370 units, 7% (±1)
1980s: about 8,410 units, 9% (±1)
1990s: about 17,370 units, 19% (±1)
2000s: about 20,860 units, 23% (±1)
2010s: about 19,660 units, 22% (±1)
2020 or later: about 5,170 units, 6% (±1)

Climate Across Johnston County

NOAA 1991 to 2020 normals for Johnston County towns, by station: Smithfield station (Smithfield, Selma, Wilson's Mills, Four Oaks and 3 more): about 3,080 heating and 1,870 cooling degree days; Clayton Water Plant station (Clayton and Archer Lodge): about 3,390 heating and 1,580 cooling degree days; Dunn 4 NW station (Benson): about 2,910 heating and 1,970 cooling degree days; Wilson 3 SW station (Kenly): about 3,060 heating and 1,840 cooling degree days.

Power and Gas in Johnston County

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

Piedmont Natural Gas holds the Johnston County gas franchise (NC Utilities Commission map), and 12 percent of Johnston County homes heat with piped gas.

Who Supplies Power in Johnston County

Duke Energy Progress: Archer Lodge, Wilson's Mills, Four Oaks, Pine Level, Kenly, Princeton and Micro; homes near Clayton, Smithfield, Selma and Benson
Clayton's own electric system: Clayton
Smithfield's own electric system: Smithfield
Selma's own electric system: Selma
Benson's own electric system: Benson
South River EMC: homes near Benson
Wake Electric: other parts of Johnston County

Energy Programs for Johnston County Homes

Check each program's current terms for a Johnston 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 Johnston County

Smart $aver Insulate and Seal (Duke Energy rebate; Archer Lodge, Wilson's Mills, Four Oaks, Pine Level and more).
Home Energy House Call (Duke Energy home assessment; Archer Lodge, Wilson's Mills, Four Oaks, Pine Level and more).
ElectriCities energy audits (ElectriCities member towns; Clayton, Smithfield, Selma and Benson).
Energy audit (South River EMC; near Benson): a walk-through home energy audit for members.
Income-qualified Weatherization (Duke Energy income-qualified; Archer Lodge, Wilson's Mills, Four Oaks, Pine Level and more).
Low-income weatherization rebate (South River EMC; near Benson): weatherization, income-qualified.
Energy Saver North Carolina (statewide income-qualified; any Johnston County address).
Weatherization Assistance Program (statewide income-qualified; any Johnston 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

Johnston County Insulation FAQs

Do you serve all of Johnston County?

Yes: Clayton, Smithfield, Selma, Archer Lodge, Benson, Wilson's Mills, Four Oaks, Pine Level and three more towns, and every unincorporated Johnston County address.

Which utilities offer insulation rebates in Johnston County?

Duke Energy's Smart $aver Insulate and Seal (Archer Lodge, Wilson's Mills, Four Oaks, Pine Level and more).

Does attic insulation in Johnston County need a permit?

Ask Johnston County Building Inspections Department before work starts. For an address in Clayton, Smithfield, Selma or another Johnston County town, the town or city hall can tell you whether Johnston County's office handles its permits.