Hampton County, SC Insulation Payback
Hampton County attic insulation, by the numbers
Hampton County sits in IECC climate zone 3 (Hot-Humid) — summers that stay hot and humid while winters barely register on the energy bill. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to R-49. Going from R-2 to the recommended R-49 costs roughly $2,820 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 3.3 years at an estimated $846/year saved. Topping up the attic pays for itself here.
Where the savings come from
Split it out and it's roughly $456 a year on the heating side, $389 on cooling. By estimated insulation savings, Hampton County lands in the 6th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Hampton County comes in 675th by savings. South Carolina averages $1,016/year across the counties tracked here; Hampton County comes in 17% lower.
The climate data behind this
The heating and cooling degree days behind this estimate — 1,720 HDD and 2,442 CDD (base 65°F, 1991-2020 normals) — come from HAMPTON 1S, SC US, the nearest NOAA station with published normals, 4.7 miles from Hampton County's center. That combined heating-and-cooling load ranks Hampton County 3038th nationally by total degree days — the 4th percentile. One local detail the R-value alone won't tell you: Hampton County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $114/year saved — roughly 14.2 years to break even. Call this borderline rather than a clear win.
Getting it done in Hampton County
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $2,820 as a starting estimate for a Hampton County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Hampton County's R-49 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-49 is the target here specifically.