Randolph County, NC Insulation Payback
Randolph County attic insulation, by the numbers
DOE classifies Randolph County as climate zone 3, mixed-humid — a genuine mix of cold winters and humid summers, with neither one dominating the bill. 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 2.4 years at an estimated $1,160/year saved. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $939 a year on the heating side, $221 on cooling. By estimated insulation savings, Randolph County lands in the 28th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Randolph County comes in 148th by savings. North Carolina averages $1,169/year across the counties tracked here; Randolph County comes in 1% lower.
Randolph County's actual weather, not a national average
Randolph County's climate figures — 3,539 heating and 1,388 cooling degree days a year — are read from ASHEBORO 2 W, NC US, 1.8 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Randolph County 2410th nationally by total degree days — the 24th percentile. One local detail the R-value alone won't tell you: Randolph County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
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 $156/year saved (~10.4-year payback). Call this borderline rather than a clear win.
Quotes and materials for this job
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $2,820 figure above as a planning number for Randolph County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Randolph 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.