Insulation and air sealing for Edisto Island homes: attics, crawl spaces, rim joists and walls, starting with a free assessment of the R-value you actually have. Edisto Island enforces the 2009 IECC (state law), which sets R-30 for a new attic.
We cover ZIP code 29438.
Our job history shows nothing in Edisto Island so far. Plenty of sites will show you a number here anyway.
Edisto Island is a rural Sea Island of about 68 square miles between the North and South Edisto rivers, shielded from the Atlantic by the beach town of Edisto Beach in Colleton County; the Charleston County part is unincorporated. Long a center of Sea Island cotton and later vegetable farming, it is dotted with plantation houses and historic churches on the National Register, and it was linked to the mainland by the Dawhoo Bridge in 1920.
Edisto Island enforces the South Carolina Energy Standard (the 2009 IECC), by state law. The Charleston County side of the island follows the county's code list, which includes the 2009 International Energy Conservation Code.
Under that edition the required attic value for new work here is R-30, and walls R-13. For comparison, the Department of Energy recommends R49 for an uninsulated attic in climate zone 3A, where Edisto Island sits, and R38 where there are already a few inches up there.
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).
Edisto Island requires a permit for this work. The county's building code lists insulation among the installations that need a permit, and the county FAQ says that apart from no-inspection jobs under $1,000 done by the homeowner or a one-trade specialty contractor, permits are needed for all work no matter the value. We pull it as part of the job.
The published number is 843-202-6930. The department page is here.
Permitting is on us, not on you.
Homes across Charleston County buy electricity from Dominion Energy South Carolina and Berkeley Electric Cooperative, and the name on the bill decides which program applies. For Dominion Energy South Carolina customers with electric heat, Home Energy Check-up Plus covers 90% of the cost of attic insulation, air sealing and duct sealing, with a ceiling of $2,880, on jobs completed by March 31, 2027 after the free Home Energy Check-up; the program's own contractor does that work, not us.
Berkeley Electric lends rather than rebates: its HomeAdvantage program lends up to $20,000 at 5%, with an energy audit first and the payments added to the electric bill. Income-qualified households can apply to Palmetto Community Action Partnership (843-720-5336) for free weatherization instead. The Charleston County page and the rebate guide carry the full rules.
Every layer of an insulated attic, explained
Edisto Island borders Johns Island, Edisto Beach, North Edisto River and South Edisto River. 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 7 of the 7 publish a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Edisto Island | 2009 IECC (state law) | R-30 | Yes | 843-202-6930 |
| Johns Island | 2009 IECC (state law) | R-30 | Yes | 843-577-5550 |
| 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 |
| Folly Beach | 2009 IECC (state law) | R-30 | Yes | 843-588-2447 |
All 22 Charleston County jurisdictions side by side →
Edisto Island 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. Edisto Island 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 members get a 5% on-bill loan instead. The federal 25C credit ended for work placed in service after December 31, 2025.
Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: charlestoncounty.gov (2, 3, 4, 5, 6, 7, 8, 9, 10) · scstatehouse.gov · www2.census.gov (2) · llr.sc.gov · en.wikipedia.org (2, 3, 4) · scencyclopedia.org · dominionenergy.com · berkeleyelectric.coop · santeecooper.com · coastal.coop · energystar.gov. These change; confirm with the building department at 843-202-6930 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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