Attic insulation, air sealing, crawl spaces and walls for homes in Bonneau — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the mid-1980s, and 0% of its 232 homes went up before 1940.
Bonneau runs to about 3.0 square miles and roughly 581 people. It sits about 37 miles north of downtown Charleston. Around 232 housing units sit inside those boundaries. The community dates back to 1911. We cover ZIP code 29431.
No completed job in Bonneau is logged in our records yet, and this page will say so until one is.
The typical home in Bonneau dates to around the mid-1980s. 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.
A small town on the east shore of Lake Moultrie at the western edge of the Francis Marion National Forest, with US 52 running through it.
The Census Bureau estimates 232 homes in Bonneau. 0 of them (0%) went up before 1940 — one of the five lowest pre-1940 shares among the 28 places on this site. The 1980s were the busiest decade, adding 73 of today's homes (31%); 38% predate 1980 and 25% were built in 2000 or later. For Berkeley County as a whole the pre-1940 share is 1%, so Bonneau sits below it.
Of 215 occupied homes, 3% heat with utility gas and 88% with electricity. Electric heat here is more common than across the county (77%), and ranks 9th 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.
77% of occupied homes are owner-occupied and 76% of all homes are single-family detached houses, with 56 mobile homes in the count. On a housing mix like this, the likely starting points are an energy assessment before deciding what to fix first.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 0 | 0% | |
| 1940s | 8 | 3% | |
| 1950s | 19 | 8% | |
| 1960s | 30 | 13% | |
| 1970s | 32 | 14% | |
| 1980s | 73 | 31% | |
| 1990s | 13 | 6% | |
| 2000s | 30 | 13% | |
| 2010s | 21 | 9% | |
| 2020 or later | 6 | 3% |
232 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 215 occupied.
86 of Bonneau's 232 homes (37%) 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.
Bonneau enforces the South Carolina Energy Standard (the 2009 IECC), by state law. The town says buildings in Bonneau should meet Berkeley County's codes, and the county's residential application lists the 2009 IECC.
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).
Nothing Bonneau publishes settles this. Its permit lists name the work types it cares about, and insulation is not among them in either direction. Bonneau's building permit page says only that a building permit worksheet must be submitted to the town and that buildings in town should meet Berkeley County's codes. It does not say which jobs need a permit. Call Town Hall to ask about an insulation job. So we ask the department directly before the first day on site, and whatever comes back, pulling it is our job rather than yours.
The town's building permit worksheet asks for the contractor's name, license number and type of license. Bonneau also has its own business license application, based on gross receipts for business done in the town, but no town page says every contractor working there must hold one.
The published number is 843-825-3385.
Permitting is on us, not on you.
Part of Bonneau sits inside Berkeley Electric Cooperative's territory, by the cooperative's own map, and Dominion Energy South Carolina, Santee Cooper and Edisto Electric Cooperative are also on record in Berkeley County: check whose name is on the electric bill first. 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. 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
Bonneau borders Lake Moultrie and Francis Marion National Forest.
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. |
|---|---|---|---|---|
| Bonneau | 2009 IECC (state law) | R-30 | Not published | 843-825-3385 |
| Unincorporated Berkeley County | 2009 IECC (state law) | R-30 | Not published | 843-719-4292 |
| Daniel Island | 2009 IECC (state law) | R-30 | Yes | 843-577-5550 |
| 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 →
Bonneau 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.
Not on paper: Bonneau names neither a permit nor an exemption for insulation, so one call to the department at 843-825-3385 settles it first.
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 of a rebate. Santee Cooper pays $500 toward ductwork only. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Bonneau dates to around the mid-1980s; the Census Bureau's 2020-2024 median year built is 1984. Of its 232 homes, 0% went up before 1940 and 25% in 2000 or later. Half the homes here are older than that and half newer; yours may sit at either end.
Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: web.archive.org (2, 3) · form.jotform.com (2) · scstatehouse.gov (2) · berkeleycountysc.gov · en.wikipedia.org · masc.sc · hub.catalogit.app · www2.census.gov · dominionenergy.com · berkeleyelectric.coop · santeecooper.com · coastal.coop · energystar.gov · data.census.gov. These change; confirm with the building department at 843-825-3385 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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