Cherokee County, SC Insulation Payback
Is attic insulation worth it in Cherokee County, SC?
Cherokee County, South Carolina is zone 3 under DOE's climate map (Mixed-Humid), which means real heating and real cooling seasons both, roughly balanced across the year. An uninsulated attic there should be built 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 2.3 years at an estimated $1,202/year saved. Few home upgrades pay back that quickly.
Where the savings come from
Heating accounts for about $1,005/year of that and cooling about $197/year — Cherokee County needs both. Nationally, Cherokee County ranks in the 31th percentile for insulation savings potential. Compared only against its own climate zone, Cherokee County places 93rd out of 690. Against South Carolina's own average of $1,016/year, Cherokee County runs 18% above that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 3,789 HDD and 1,235 CDD (base 65°F, 1991-2020 normals) — come from NINETY NINE IS, SC US, the nearest NOAA station with published normals, 6.6 miles from Cherokee County's center. Combined heating and cooling load puts Cherokee County in the 27th percentile of this 3,162-county dataset. Its moisture regime is classified humid, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
If the attic isn't bare
A shallower starting point changes the math: with R-11 already down, only the gap to R-38 needs filling, at roughly $1,620 for an estimated $162/year saved (~10-year payback). Whether that is worth it depends on how long you plan to stay.
Quotes and materials for this job
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 Cherokee County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Cherokee County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Cherokee County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.