Duplin County, NC Insulation Payback
Duplin County attic insulation, by the numbers
DOE classifies Duplin 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. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-49 runs an estimated $2,820, and saves about $1,152 a year in heating and cooling — a payback around 2.4 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $926 a year on the heating side, $226 on cooling. By estimated insulation savings, Duplin County lands in the 28th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Duplin County comes in 160th by savings. North Carolina averages $1,169/year across the counties tracked here; Duplin County comes in 1% lower.
Where these numbers come from
Duplin County's climate figures — 3,489 heating and 1,419 cooling degree days a year — are read from WARSAW 5 E, NC US, 6.7 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Duplin County in the 23th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Duplin 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 $155/year saved — roughly 10.4 years to break even. Call this borderline rather than a clear win.
Getting it done in Duplin 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 Duplin County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Duplin 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.