Attic insulation, air sealing, crawl spaces and walls for homes in James Island — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the early-1970s, and 0% of its 4,971 homes went up before 1940.
James Island runs to about 4.8 square miles and roughly 12,198 people. It sits about 3 miles south of downtown Charleston. There are around 4,971 housing units here. The community dates back to 2012. We cover ZIP code 29412.
We have not logged a completed job in James Island yet. We would rather say so than put a number on this page that is not real.
The typical home in James Island dates to around the early-1970s. Postwar building here often meant three or four inches of fiberglass and no attempt at air sealing. If nobody has touched it since, that is what is still up there.
We work across James Island rather than one corner of it — Riverland Terrace, Lynwood, White Point Estates, Stiles Point Plantation, Eastwood, Harbor Woods, Seaside Plantation, Parrot Creek, Lawton Harbor and Sol Legare 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.
James Island was long a semi-rural island and has been reshaped by growing urban and suburban development. The Town of James Island covers the central and southern parts of the island, with City of Charleston neighborhoods and unincorporated county land mixed in, because the city annexed land on the island before and between the town's four incorporations. Riverland Terrace, one of the island's oldest neighborhoods, was laid out starting in 1925 along Wappoo Creek.
The Census Bureau estimates 4,971 homes in James Island. 0 of them (0%) went up before 1940 — 20th of 28 places on this site for pre-1940 housing. The 1960s were the busiest decade, adding 1,797 of today's homes (36%); 68% predate 1980 and 11% were built in 2000 or later. For Charleston County as a whole the pre-1940 share is 5%, so James Island sits below it.
Of 4,666 occupied homes, 35% heat with utility gas and 61% with electricity. Electric heat here is less common than across the county (76%), and ranks 28th of 28 on this site. That is why the assessment asks how the house is heated: the fuel and the name on the utility bill decide which program, if any, can pay toward the work.
88% of occupied homes are owner-occupied and 92% of all homes are single-family detached houses, with 93 mobile homes in the count. On a housing mix like this, the likely starting points are an attic top-up over postwar fiberglass and an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 0 | 0% | |
| 1940s | 25 | 1% | |
| 1950s | 651 | 13% | |
| 1960s | 1,797 | 36% | |
| 1970s | 915 | 18% | |
| 1980s | 511 | 10% | |
| 1990s | 525 | 11% | |
| 2000s | 308 | 6% | |
| 2010s | 209 | 4% | |
| 2020 or later | 30 | 1% |
4,971 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 4,666 occupied.
3,363 of James Island's 4,971 homes (68%) date from 1950 through 1979. The leaks in houses of that era repeat: nothing over the top plates, wire and pipe holes left open, an unsealed hatch, a bath fan venting into the attic, and in ranches and split-levels, heat lost at the garage ceiling and over cantilevered floors. Sealing the plates, holes and fans comes before any more fiber, and it is usually a day's work, not a renovation.
James Island enforces the South Carolina Energy Standard (the 2009 IECC), by state law. The town publishes no code list of its own; its building official enforces the state's energy standard, the 2009 IECC, like every building official in South Carolina.
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).
James Island publishes no answer either way. Insulation and air sealing appear on neither the permit-required list nor the exempt list. The town does not say whether adding insulation on its own needs a permit. Its building permit fee schedule applies to new construction, additions, alterations and renovations, starting at $125 for work costing up to $5,000, and the town asks anyone unsure which permit they need to call Town Hall. We confirm it with the department before we start and pull whatever is needed. We would rather write that here than guess on your behalf.
The published number is 843-795-4141. 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 James Island; the other electric utility on record for Charleston County is Dominion Energy South Carolina. 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.
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
James Island borders Charleston, Folly Beach, Johns Island, Stono River and Folly 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 6 of the 7 publish a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| James Island | 2009 IECC (state law) | R-30 | Not published | 843-795-4141 |
| Charleston | 2009 IECC (state law) | R-30 | Yes | 843-577-5550 |
| Folly Beach | 2009 IECC (state law) | R-30 | Yes | 843-588-2447 |
| 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 |
| Unincorporated Charleston County | 2009 IECC (state law) | R-30 | Yes | 843-202-6930 |
All 22 Charleston County jurisdictions side by side →
James 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.
James Island publishes no rule either way, so we ask its building department at 843-795-4141 before the job is scheduled.
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 James Island dates to around the early-1970s; the Census Bureau's 2020-2024 median year built is 1970. Of its 4,971 homes, 0% went up before 1940 and 11% 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: jamesislandsc.us (2, 3, 4, 5, 6, 7, 8, 9) · charlestoncounty.gov (2, 3, 4) · scstatehouse.gov (2) · charleston-sc.gov (2) · en.wikipedia.org (2, 3, 4, 5, 6) · gis.charleston-sc.gov · nationalregister.sc.gov · scdah.sc.gov · www2.census.gov · dominionenergy.com · berkeleyelectric.coop · santeecooper.com · coastal.coop · energystar.gov · data.census.gov. These change; confirm with the building department at 843-795-4141 or the utility named on your electric bill first.
Free assessment, measured at the hatch, with the photographs and the number in writing.
Book my free assessment →