Cary, NC
5 miles northeast
Median home built 1999 (Apex: 2008); Power from Duke Energy (Apex: a town system)
Attic insulation in CaryAttic Insulation in Apex, NC
Blown-in attic insulation for Apex, NC, 5 miles from Cary, plus removal and air sealing.
About Apex and Its Homes
Apex began as a depot on the Chatham Railroad, which reached it in 1869, and was chartered in 1873. Its National Register district records frame houses from the 1870s into the 1950s around Salem Street, while most homes in town are far newer and stand in later subdivisions.
Apex, in Wake County, grew from 65,249 people in 2020 to 80,419 in 2025 (Census Bureau estimates), on 25.7 square miles. That makes Apex the third-largest town in Wake County.
Apex has about 27,000 housing units, 5 percent of Wake County's; 77 percent of the town's households own their home.
Apex at a Glance
- County: Wake County
- Population: 80,419 (2025), 65,249 (2020), up 23.2%
- Land area: 25.7 square miles (3,128 people each)
- Housing units: about 27,000 (±732)
- Median year built: 2008 (±1); Wake County: 2000
- Owner-occupied: 77% (±2); Wake County: 64%
- Detached houses: 67% (±2); Wake County: 58%
- Attached houses: 16% (±2)
- Apartments: 16% (±2)
- Climate zone: 4 (state code), 3 (2021 map)
- ENERGY STAR target for Apex attics: R-49 from bare, R-38 over 3 to 4 inches (R-value guide)
Census Bureau estimates for Apex, 2020 to 2024 (± margin of error).
Apex Homes and Their Attics
Queen Anne Cottages East of the Railroad
In 1906 the Apex Land and Improvement Company split farmland east of the tracks into house lots along Hughes, Mason, Olive and Moore streets. Over the next decade, the 1995 nomination for this part of the district records, families there built frame Queen Anne houses. A number had pyramidal roofs, cross gables, hipped dormers, bay windows and front and rear ells. A roof put together from that many pieces covers several attic pockets, not one big room. The main block, each ell and each wing can hide a separate space. We open up and look into every section, then spread the new layer level across all of them.
Bungalows With Interior Chimneys Near Salem Street
The 1994 district nomination singles out a 1917 bungalow on South Salem Street, drawn by Raleigh architect Frank Simpson, with interior chimneys under a side-gable roof. On Center Street it lists bungalows from about 1915 to 1925 with dormers, one of them with inside brick chimneys. The 2002 addition, on Hunter, Grove and Thompson streets, is mostly bungalows, triple-A houses and hip-roofed cottages. When an Apex bungalow chimney climbs up past the ceiling joists, any gap between the brick and the framing lets house air slip up through the slack. We bridge that slack with thin aluminum sheet, sealed at its edges with high-heat caulk. A small sheet-metal dam then stands off the masonry so loose fill cannot slump against it.
Minimal Traditional and Ranch Houses After 1940
The district's 1995 nomination records the first ranch house in Apex, built in 1950 on South Hughes Street. The 2008 addition carries the story to 1959. Its one-story Minimal Traditional and Ranch houses from the 1940s and 1950s sit farther from Salem Street than the older homes, turned with their long side to the street. Many were built of concrete block or sided with asbestos shingles. With a roof pitched that low, the rafters come down almost onto the ceiling joists at the outer walls. ENERGY STAR finds the middle of an attic sometimes well covered while the strip along the eaves stays thin. We work the fill out into that strip and fit baffles first, so soffit air still has a channel.
Attic Insulation in Apex
If the joists show above the insulation in an Apex attic, ENERGY STAR says to add more insulation.
In 2010 or later, 46 percent of Apex homes went up; check their air sealing as well as the depth.
The Local Climate
Apex's center sits about 500 feet above sea level, 1 mile from NOAA's Apex station, the best match for Apex. The station's 1991 to 2020 normals average about 3,350 heating and 1,610 cooling degree days a year, so at Apex's station, heating needs outweigh cooling.
Homes by Age: What It Means for the Attic
Some 67 percent of Apex housing units are detached single-family houses.
From 1990 to 2009, 44 percent of Apex 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: 1% (±1), about 185 units
- 1940s: 0% (±1), about 80 units
- 1950s: 1% (±1), about 235 units
- 1960s: 1% (±1), about 175 units
- 1970s: 1% (±1), about 350 units
- 1980s: 7% (±2), about 1,780 units
- 1990s: 20% (±2), about 5,300 units
- 2000s: 24% (±2), about 6,300 units
- 2010s: 36% (±2), about 9,500 units
- 2020 or later: 10% (±2), about 2,600 units
Air Sealing and Duct Sealing in Apex
In Apex, 35 percent of homes heat with electricity and 64 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: 35% (±3), about 8,800 households; Wake County: 55%
- Piped gas: 64% (±2), about 16,100 households
Power, Gas and Rebates
Apex, an ElectriCities public power town, runs its own electric system. For gas, Apex is in the Wake County franchise of Enbridge Gas North Carolina, and 64 percent of the town's homes heat with piped gas.
Program to ask about in Apex: ElectriCities energy audits (the town's electric system), home energy audits for member-town customers; ask the town's utility office. Before a job in Apex, check its current terms; the Wake County page lists every program.
Attic Insulation Removal in Apex
In an Apex attic, only wet, moldy or animal-soiled insulation is vacuumed out (ENERGY STAR's test), once the cause is fixed, and after mice that Apex attic is sanitized and deodorized; dry, clean insulation stays.
Also Serving Near Apex
Nearest to Apex first.
Holly Springs, NC
5 miles southeast
Median home built 2008, as in Apex
Attic insulation in Holly SpringsMorrisville, NC
8 miles north
Median home built 2007 (Apex: 2008); Center about 200 feet lower than Apex's
Attic insulation in MorrisvilleFuquay-Varina, NC
11 miles southeast
Median home built 2011 (Apex: 2008)
Attic insulation in Fuquay-VarinaGarner, NC
15 miles east
Median home built 2001 (Apex: 2008); Its NOAA station logs about 280 more heating degree days than Apex's
Attic insulation in Garner
Apex Insulation FAQs
Is attic work on a house in the Apex Historic District reviewed by anyone?
Not for work inside the house. As the state's historic preservation office explains it, being on the National Register does not restrict how an owner maintains or changes the property at the owner's own expense. A handful of Apex properties, the old depot among them, are designated landmarks, and any change to a landmark's outside needs a certificate of appropriateness. The Small Town Character Overlay sets design standards for new building and redevelopment downtown. Insulating and sealing an attic happens indoors. A new roof or soffit vent is outside work, so talk to the planners before cutting one.
Before you insulate a Salem Street house from around 1900, who checks the wiring?
An electrician, first. The district's nominations date houses on Salem and Center streets to the years from about 1900 to 1925, and the district's oldest houses to the 1870s. Wiring of that age is sometimes knob-and-tube. ENERGY STAR treats it as a fire hazard wherever insulation would bury it, in any house wired before roughly 1930. When some of it still carries power, the electrician sorts it out before we begin. Until that is done, that part of the attic is left bare.
The room above our Apex garage is always the hottest in the house. Why?
Because it is wrapped in unconditioned space. The garage lies under its floor, and wedge-shaped attics sit behind its low side walls. Building America guidance for living space above a garage is to make that floor airtight and keep its insulation pressed up to the subfloor. ENERGY STAR lists the open cavities behind and under knee walls with the worst air leaks in a typical attic. In an Apex house we seal and fill those side attics, plus the garage ceiling where it is open. We also offer garage insulation as its own job.
Does attic insulation in Apex need a permit?
Apex Town Hall can say whether Wake County Permits and Inspections, the town itself or another office handles permits in Apex; ask before work starts.
Helpful Guides
- Median home built 2008: bonus rooms over garages
- An energy audit program from the town's own utility: home energy audits
Sources
Census Bureau figures for Apex, NOAA normals for the Apex station, Apex's municipal electric system (October 2026). Compiled by Insulation Pros. How the town pages are made.
Sources for the Apex notes and questions (read October 20, 2026):
- Apex Historic District, National Register nomination (NC HPO, listed 1994)
- Apex Historic District (Boundary Increase), National Register nomination (NC HPO, listed 1995)
- Apex Historic District Boundary Increase II, National Register nomination (NC HPO, listed 2002)
- Apex Historic District Boundary Increase III, National Register nomination (NC HPO, listed 2008)
- Year Structure Built (table B25034), Apex town, American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau via Census Reporter
- Adding Attic Insulation, ENERGY STAR do-it-yourself guide
- Furnace Flues Require Special Sealing Techniques, ENERGY STAR do-it-yourself guide
- Post-World War II and Modern Architecture in Raleigh, North Carolina, 1945-1965, National Register multiple property documentation form (NC HPO)
- About Attic Ventilation, ENERGY STAR do-it-yourself guide
- What Is the National Register of Historic Places?, NC State Historic Preservation Office
- Our History, Town of Apex
- Small Town Character Overlay District and Historic Properties, Town of Apex
- N.C. Gen. Stat. 160D-947, Certificate of appropriateness required
- Attic Insulation Project, ENERGY STAR
- Floor Above Garage, Building America Solution Center (Pacific Northwest National Laboratory, U.S. DOE)
- Attic Air Sealing Project, ENERGY STAR
Serving Apex, NC
Insulation Pros is an insulation contractor serving North Carolina, Apex and the rest of Wake County included.
Reach us
Send the square footage of your Apex attic, or call (336) 870-3893.