Lee County, SC Insulation Payback
Is attic insulation worth it in Lee County, SC?
DOE classifies Lee County as climate zone 3, mixed-humid — heating load in winter and cooling load in summer, both worth taking seriously here. Its recommended attic R-value for bare joists is 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 2.7 years at an estimated $1,036/year saved. Few home upgrades pay back that quickly.
The breakdown behind the number
Heating accounts for about $730/year of that and cooling about $306/year — Lee County needs both. Nationally, Lee County ranks in the 19th percentile for insulation savings potential. Compared only against its own climate zone, Lee County places 397th out of 690. Against South Carolina's own average of $1,016/year, Lee County runs 2% above that.
The climate data behind this
Lee County's climate figures — 2,752 heating and 1,921 cooling degree days a year — are read from BISHOPVILLE 1ENE, SC US, 3.8 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Lee County in the 16th 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.
Already have some insulation?
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $140/year saved — roughly 11.6 years to break even. Whether that is worth it depends on how long you plan to stay.
Quotes and materials for this job
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Lee County's estimated $1,036/year on the line.
Lee County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Lee 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.