Attic insulation, air sealing, crawl spaces and walls for homes in Folly Beach — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the early-1990s, and 3% of its 2,221 homes went up before 1940.
Folly Beach runs to about 12 square miles and roughly 1,267 people. It sits about 8 miles south of downtown Charleston. There are around 2,221 housing units here. The community dates back to 1973. We cover ZIP code 29439.
We have not logged a completed job in Folly Beach yet. We would rather say so than put a number on this page that is not real.
The typical home in Folly Beach dates to around the early-1990s. Houses of this vintage usually got batts or blown fiber at whatever the standard of the day was, which is well short of what is recommended now. Most are one top-up away from being right.
Beach cottages grew out of early camps, and steady building from the 1940s on reached its peak in the 1960s.
Folly Beach covers most of Folly Island, a barrier island on the Atlantic; about a third of the city's area is water. Temporary beach camps turned into cottages, building peaked in the 1960s, and Hurricane Hugo damaged homes in 1989. The only road on and off the island is S.C. 171, which crosses the Folly River to James Island.
The Census Bureau estimates 2,221 homes in Folly Beach. 60 of them (3%) went up before 1940 — 11th of 28 places on this site for pre-1940 housing. The 1990s were the busiest decade, adding 518 of today's homes (23%); 30% predate 1980 and 27% were built in 2000 or later. For Charleston County as a whole the pre-1940 share is 5%, so Folly Beach sits below it.
Of 619 occupied homes, 33% heat with utility gas and 67% with electricity. Electric heat here is less common than across the county (76%), and ranks 25th of 28 on this site. Whoever comes out will ask about the furnace or heat pump first, since the heating fuel and the utility named on the bill settle which program money is on the table.
95% of occupied homes are owner-occupied and 65% of all homes are single-family detached houses. With houses like these, the conversations we expect most are about an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 60 | 3% | |
| 1940s | 227 | 10% | |
| 1950s | 185 | 8% | |
| 1960s | 144 | 6% | |
| 1970s | 50 | 2% | |
| 1980s | 427 | 19% | |
| 1990s | 518 | 23% | |
| 2000s | 470 | 21% | |
| 2010s | 86 | 4% | |
| 2020 or later | 54 | 2% |
2,221 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 619 occupied.
945 of Folly Beach's 2,221 homes (43%) were built in the 1980s and 1990s. The gaps in houses of that age are the parts nobody sealed: batts stuffed into the rim joist, bare spots over cathedral and tray ceilings, soffit vents buried with no baffles, can lights punched through the ceiling plane. A top-up plus a day of sealing usually covers it.
Folly Beach enforces the South Carolina Energy Standard (the 2009 IECC), by state law. The city posts the state notices for the 2021 codes, in force since January 1, 2023, and for the 2024 editions that local governments start enforcing on January 1, 2027.
For new work, the attic number under that edition is R-30, with walls at R-13. Set that against the Department of Energy, which recommends R49 for an uninsulated attic in this climate zone and R38 for one that already has a few inches.
Table 402.1.1 of the 2009 IECC, climate zone 3, which South Carolina's Energy Standard Act adopts for the whole state (section 6-10-30 of the South Carolina Code).
Folly Beach requires a permit for this work. Folly Beach says building permits are required for all new construction, remodeling and repairs, and that this "includes interior and exterior work on existing homes." The city's energy compliance form for remodels lists the 2009 code minimums (ceiling R-30, walls R-13, floors R-19) and says a REScheck report must be turned in with the permit application. We pull it as part of the job.
The published number is 843-588-2447. The department page is here.
Permitting is on us, not on you.
Berkeley Electric Cooperative's own territory map shows none of its service inside Folly Beach; the other electric utility on record for Charleston County is Dominion Energy South Carolina. If Dominion Energy South Carolina sends the bill and the house heats with electricity, Check-up Plus covers 90% of an attic, air sealing and duct sealing job, to $2,880, through March 31, 2027; it starts with Dominion's free check-up and uses the program's own contractor.
Income-qualified households can apply to Palmetto Community Action Partnership (843-720-5336) for free weatherization instead. Every condition attached is on the Charleston County page and in the rebate guide.
Every layer of an insulated attic, explained
Folly Beach borders James Island, Folly River and Atlantic Ocean. These are the ones we also cover, each with its own energy code and permit rule:
Elsewhere in Charleston County we also cover:
South Carolina sets the residential energy code statewide, so the attic figure is R-30 wherever it is published here; what changes is the permit desk, and 6 of the 7 publish a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Folly Beach | 2009 IECC (state law) | R-30 | Yes | 843-588-2447 |
| James Island | 2009 IECC (state law) | R-30 | Not published | 843-795-4141 |
| Adams Run | 2009 IECC (state law) | R-30 | Yes | 843-202-6930 |
| Awendaw | 2009 IECC (state law) | R-30 | Yes | 843-202-6930 |
| Charleston | 2009 IECC (state law) | R-30 | Yes | 843-577-5550 |
| Unincorporated Charleston County | 2009 IECC (state law) | R-30 | Yes | 843-202-6930 |
| Edisto Island | 2009 IECC (state law) | R-30 | Yes | 843-202-6930 |
All 22 Charleston County jurisdictions side by side →
Folly Beach enforces the 2009 IECC (state law), which sets R-30 for an attic in new work. Whether it reaches a retrofit of an existing house is not published.
Yes. Folly Beach requires a permit for this work, and we pull it as part of the job.
Dominion Energy South Carolina's Check-up Plus pays 90% of attic insulation, air sealing and duct sealing, up to $2,880, until March 31, 2027, for electrically heated homes; the program's contractor does the work. Berkeley Electric's map shows none of its service here. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Folly Beach dates to around the early-1990s; the Census Bureau's 2020-2024 median year built is 1990. Of its 2,221 homes, 3% went up before 1940 and 27% in 2000 or later. That is a median across the whole place, so your own house may be older or newer.
Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: cityoffollybeach.com (2, 3, 4, 5, 6, 7, 8, 9, 10, 11) · scstatehouse.gov (2) · en.wikipedia.org (2, 3, 4) · visitfolly.com · charlestoncitypaper.com · dominionenergy.com · berkeleyelectric.coop · santeecooper.com · coastal.coop · energystar.gov · data.census.gov. These change; confirm with the building department at 843-588-2447 or the utility named on your electric bill first.
Free assessment, a measured R-value, and photos you keep either way.
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