Morrisville, NC
4 miles north
Median home built 2007 (Cary: 1999); Center about 200 feet lower than Cary's
Attic insulation in MorrisvilleAttic Insulation in Cary, NC
Blown-in attic insulation for Cary, NC, in Wake County, plus removal and air sealing.
About Cary and Its Homes
Cary began as a railroad stop: the North Carolina Rail Road came through in 1856, and the town was incorporated in 1871. Its 2001 historic district nomination covers houses from the 1890s to the 1940s south of the tracks and marks 1945 as the start of the great postwar suburban growth.
Cary, in Wake County, grew from 174,773 people in 2020 to 183,582 in 2025 (Census Bureau estimates), on 60.1 square miles. That makes Cary the second-largest town in Wake County.
Cary has about 74,000 housing units; 67 percent of the town's households own their home.
Cary at a Glance
- County: Wake County
- Population: 183,582 (2025), 174,773 (2020), up 5.0%
- Land area: 60.1 square miles (3,053 people each)
- Housing units: about 74,000 (±1,157)
- Median year built: 1999 (±2); Wake County: 2000
- Owner-occupied: 67% (±1); Wake County: 64%
- Detached houses: 59% (±1); Wake County: 58%
- Attached houses: 14% (±1)
- Apartments: 26% (±2)
- Climate zone: 4 (state code), 3 (2021 map)
- ENERGY STAR target for Cary attics: R-49 from bare, R-38 over 3 to 4 inches (R-value guide)
Census Bureau estimates for Cary, 2020 to 2024 (± margin of error).
Cary Homes and Their Attics
I-Houses and Bungalows Along South Academy Street
The Cary Historic District holds thirty historic houses dated from about 1890 to 1945, with South Academy Street as its spine. Most are modest frame or brick-veneered bungalows and period cottages, and a few are two-story frame I-houses under the triple-A roof the nomination calls common for the period. Should one of those tall frame houses turn out to be balloon framed, the hollow spaces inside its walls can open directly into the attic, with no plate capping them. House air then climbs those channels unchecked. We locate those openings and block them from above before laying any insulation.
The Research Triangle Park Years
IBM announced in 1965 that it was coming to the area, and by 1982 its employment had reached 8,500. Raleigh's postwar survey records that for the rest of the century, North Raleigh and Cary took in some three-quarters of the families of Research Triangle Park employees, in new subdivisions. Cary's housing numbers elsewhere on this page put the large majority of homes in 1970 or after. If your ceilings have recessed cans, look for an IC rating on the housing. ENERGY STAR keeps insulation back 3 inches from cans that lack the rating, while rated fixtures can be covered, and every can is a leak point worth sealing.
Attic Insulation in Cary
If the joists show above the insulation in a Cary attic, ENERGY STAR says to add more insulation.
From 1990 to 2009, 48 percent of Cary homes were built to codes below ENERGY STAR's target; check their eaves, where ENERGY STAR says insulation is often thinnest.
The Local Climate
Cary's center sits about 500 feet above sea level, 5 miles from NOAA's Apex station, the best match for Cary. The station's 1991 to 2020 normals average about 3,350 heating and 1,610 cooling degree days a year, so at Cary's station, heating needs outweigh cooling.
Homes by Age: What It Means for the Attic
Some 59 percent of Cary housing units are detached single-family houses.
In 2010 or later, 26 percent of Cary homes went up; check their air sealing as well as the depth.
About 12 percent of Cary's housing units predate 1980; nearly all predate the state's 1978 insulation rule too. Some 26 percent of Cary units sit in buildings of two or more homes, where the attic is often shared.
Homes by Year Built
- Before 1940: 0% (±1), about 300 units
- 1940s: 0% (±1), about 70 units
- 1950s: 1% (±1), about 680 units
- 1960s: 2% (±1), about 1,820 units
- 1970s: 8% (±1), about 6,000 units
- 1980s: 14% (±1), about 10,500 units
- 1990s: 25% (±1), about 18,500 units
- 2000s: 23% (±1), about 17,000 units
- 2010s: 22% (±1), about 16,500 units
- 2020 or later: 3% (±1), about 2,500 units
Air Sealing and Duct Sealing in Cary
In Cary, 43 percent of homes heat with electricity and 55 percent with piped gas; forced air from either moves through ducts.
Air sealing comes first, as the EPA advises: wire and pipe holes, wall tops and soffits.
How Homes Here Are Heated
- Electricity: 43% (±2), about 30,000 households; Wake County: 55%
- Piped gas: 55% (±2), about 38,000 households
Power, Gas and Rebates
Duke Energy supplies Cary's electricity. For gas, Cary is in the Wake County franchise of Enbridge Gas North Carolina, and 55 percent of the town's homes heat with piped gas. Duke's free House Call fits many Cary homes: 43 percent heat with electricity.
Rebate to check in Cary: Smart $aver Insulate and Seal (Duke Energy; Insulation Pros is an approved trade ally). Before a job in Cary, check its current terms; the Wake County page lists every program.
Attic Insulation Removal in Cary
In a Cary attic, only wet, moldy or animal-soiled insulation is vacuumed out (ENERGY STAR's test), once the cause is fixed, and after mice that Cary attic is sanitized and deodorized; dry, clean insulation stays.
Also Serving Near Cary
Nearest to Cary first.
Apex, NC
5 miles southwest
Median home built 2008 (Cary: 1999); Power from its own town system (Cary: Duke Energy)
Attic insulation in ApexHolly Springs, NC
9 miles south
50,288 people, about a quarter of Cary's population
Attic insulation in Holly SpringsRaleigh, NC
11 miles east
Median home built 1997 (Cary: 1999); Center about 180 feet lower than Cary's
Insulation contractor serving RaleighFuquay-Varina, NC
13 miles south
Median home built 2011 (Cary: 1999); 48,536 people, about a quarter of Cary's population
Attic insulation in Fuquay-Varina
Cary Insulation FAQs
Does being in the Cary Historic District restrict changes to my house?
Not on its own. Its National Register listing dates to 2001. The state preservation office is clear that Register status, by itself, ties no conditions to repairs or changes an owner pays for privately. Separately, Cary has its own Historic Preservation Commission, which oversees outside changes only where the town has designated a local landmark or district. Insulating the attic is indoor work either way. Ask the town before adding roof vents.
Why does the bonus room over my Cary garage never feel right?
Start with the floor. Building America's guide for a room over a garage puts air sealing that floor first. The cavities are then filled so the insulation presses up against the subfloor rather than sagging away from it. Air slipping between the garage and the room above undoes the heating and cooling. Garage insulation is a service we offer, and we can check the floor and the small attics beside the room together.
How is an old brick chimney handled in an attic near downtown Cary?
Sealed at the gap, then kept clear of insulation. Three houses in the district inventory are described with an interior brick chimney, meaning the stack rises through the ceiling into the attic. ENERGY STAR's approach is a collar of aluminum flashing over the gap, its edges run with caulk rated for high heat, plus a sheet-metal guard holding loose insulation away. Codes usually ask for 2 inches from masonry. Foam is never used there.
Are there rebates for attic insulation in Cary?
Duke Energy's Smart $aver Insulate and Seal is the one to check: a rebate for attic insulation done together with air sealing, and a separate one for duct sealing, when the attic starts at R-19 or less; a contractor in Duke's Smart $aver network must do the work, and Insulation Pros is an approved Duke Energy trade ally. Check its current terms. The Wake County page lists every other program.
Does attic insulation in Cary need a permit?
Cary Town Hall can say whether Wake County Permits and Inspections, the town itself or another office handles permits in Cary; ask before work starts.
Helpful Guides
- Power from Duke Energy: high summer electric bills and home energy audits
Sources
Census Bureau figures for Cary, NOAA normals for the Apex station, Duke Energy (October 2026). Compiled by Insulation Pros. How the town pages are made.
Sources for the Cary notes and questions (read October 20, 2026):
- Cary Historic District, National Register nomination (NC HPO)
- Cary, in The North Carolina Gazetteer (William S. Powell, 2nd ed., UNC Press 2010), NCpedia
- NC Listings in the National Register of Historic Places, NC State Historic Preservation Office
- Building Construction Problem Areas, weatherization training text, Iowa Department of Health and Human Services
- Post-World War II and Modern Architecture in Raleigh, North Carolina, 1945-1965, National Register multiple property documentation form (NC HPO)
- Year Structure Built (table B25034), Cary town, American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau via Census Reporter
- Attic Insulation Project, ENERGY STAR
- Attic Air Sealing Project, ENERGY STAR
- 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)
- N.C. Gen. Stat. 160D-947, Certificate of appropriateness required
- Floor Above Garage, Building America Solution Center (Pacific Northwest National Laboratory, U.S. Department of Energy)
- Furnace Flues Require Special Sealing Techniques, ENERGY STAR do-it-yourself guide
Serving Cary, NC
Insulation Pros is an insulation contractor serving North Carolina, Cary and the rest of Wake County included.
Reach us
Send the square footage of your Cary attic, or call (336) 870-3893.