All 36 cities and jurisdictions we cover, in 3 counties, each with the energy code that actually applies there, the attic R-value it requires, the permit position and the department's own number. South Carolina sets the energy code by statute, so the attic figure is the same in all three counties; what changes is the permit desk.
South Carolina writes its residential energy code into state law. The Energy Standard Act adopts the 2009 edition of the International Energy Conservation Code as the state's Energy Standard, every city, town and county enforces it through its own building official, and a local government may vary it only with the approval of the South Carolina Building Codes Council.
In climate zone 3, where all three counties sit, that edition asks R-30 for an attic and R-13 for a wood frame wall in new work. The model code has moved on since 2009 and the state has not, so those figures are a floor; the Department of Energy's recommendation for this zone is higher, and every town page shows both.
What does change from one town to the next is the permit desk: whether it names insulation as permit work, what it asks of a contractor, and in a flood zone how it counts improvements toward the 50 percent rule. Each page below says what that place publishes, and says so when it publishes nothing.
These pages exist so you can check your own address before anyone quotes you. Every figure on them comes from the jurisdiction's own published page, its codified ordinance, the state code, or the utility's own published incentive table, and every page says where it came from. Where a city does not publish something, we leave it blank rather than filling it in.
Municipal and county research 2026-10-24; energy code, R-value and rebate research 2026-10-24. Holy City Insulation is a service-area business serving greater Charleston.
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