Attic insulation, air sealing, crawl spaces and walls for homes in Daniel Island — starting with a free assessment that measures the R-value you actually have. Daniel Island enforces the 2009 IECC (state law), which sets R-30 for a new attic.
The community dates back to 1996. We cover ZIP code 29492.
We have not logged a completed job in Daniel Island yet. We would rather say so than put a number on this page that is not real.
Neighborhoods follow a new-urbanist, neo-traditional master plan with grid streets and sidewalks, all built since 1996.
We work across Daniel Island rather than one corner of it — Daniel Island Park, Codner's Ferry Park and The Waterfront included. Construction and vintage change between them, sometimes by thirty years and a whole different framing method, which decides whether a wall can be dense-packed at all.
A roughly 4,000-acre island between the Cooper and Wando rivers in the Berkeley County part of the City of Charleston, which annexed it in 1991. Long used for farming, cattle and hunting, it stayed undeveloped until the Mark Clark Expressway (I-526) crossed it, and homes have been built since 1996 as a master-planned community with neighborhoods grouped around parks and surrounded by rivers and tidal creeks.
Depth is rarely what is missing in houses this new; air paths are: attached garages, bonus rooms over them, the chase around a high-efficiency flue, and the thin edge where blown fiber meets the wall plate. They usually earn their money back on sealing rather than on more fiber.
Daniel Island enforces the South Carolina Energy Standard (the 2009 IECC), by state law. Daniel Island is inside Charleston city limits, so the city's list applies: the 2009 International Energy Conservation Code with the 2021 South Carolina Residential Code.
That edition sets R-30 for the attic in new work, and R-13 for walls. The Department of Energy's recommendation for this climate zone runs higher: R49 for an attic with nothing in it, R38 where a few inches are already down.
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).
Daniel Island requires a permit for this work. Daniel Island is inside Charleston city limits, and the city says "a permit must be obtained from Building Inspections for any work being done in the City of Charleston." Its residential alteration permit lists an insulation inspection, and in flood zones AE and VE the city says all work on an existing home needs a permit, including non-structural interior work. We pull it as part of the job.
The published number is 843-577-5550. 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 Daniel Island; the other electric utilities on record for Berkeley County are Dominion Energy South Carolina, Santee Cooper and Edisto Electric Cooperative. Dominion Energy South Carolina's Check-up Plus is the big one: 90% of attic insulation, air sealing and duct sealing paid, up to $2,880, until March 31, 2027, for electrically heated homes that have had the free check-up, with the work done by Dominion's approved contractor.
Santee Cooper's 2026 program pays $500 toward replacing most of a home's ductwork, but nothing toward insulation. Income-qualified households can apply to Palmetto Community Action Partnership (843-720-5336) for free weatherization instead. Every condition attached is on the Berkeley County page and in the rebate guide.
Every layer of an insulated attic, explained
Daniel Island borders Cooper River, Wando River, Nowell Creek and Beresford Creek.
Elsewhere in Berkeley 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 2 of the 7 publish a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Daniel Island | 2009 IECC (state law) | R-30 | Yes | 843-577-5550 |
| Unincorporated Berkeley County | 2009 IECC (state law) | R-30 | Not published | 843-719-4292 |
| Bonneau | 2009 IECC (state law) | R-30 | Not published | 843-825-3385 |
| Goose Creek | 2009 IECC (state law) | R-30 | Not published | 843-797-6220 ext. 1508 |
| Hanahan | 2009 IECC (state law) | R-30 | Yes | 843-576-5259 |
| Ladson | 2009 IECC (state law) | R-30 | Not published | 843-719-4292 |
| Moncks Corner | 2009 IECC (state law) | R-30 | Not published | 843-719-7914 |
All 10 Berkeley County jurisdictions side by side →
Daniel 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. Daniel Island requires a permit for this work, and we pull it as part of the job.
If Dominion Energy South Carolina is your electric utility and the house has electric heat, Check-up Plus pays 90% of attic insulation, air sealing and duct sealing, up to $2,880, through March 31, 2027, through its own contractor. Berkeley Electric's map shows none of its service here. Santee Cooper pays $500 toward ductwork only. 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: charleston-sc.gov (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14) · scstatehouse.gov · en.wikipedia.org · thedanielislandnews.com (2) · danielisland.com (2) · statelibrary.sc.gov · dominionenergy.com · berkeleyelectric.coop · santeecooper.com · coastal.coop · energystar.gov. These change; confirm with the building department at 843-577-5550 or the utility named on your electric bill first.
Free assessment: what depth you have now, what it has settled to, and what the sealing is worth.
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