Carteret County, NC Insulation Payback
Carteret County attic insulation, by the numbers
Carteret County, North Carolina is zone 3 under DOE's climate map (Hot-Humid), which means long, muggy summers and mild winters, where cooling dominates the energy bill. 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 3 years at an estimated $946/year saved. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $631 a year on the heating side, $315 on cooling. By estimated insulation savings, Carteret County lands in the 13th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Carteret County comes in 584th by savings. North Carolina averages $1,169/year across the counties tracked here; Carteret County comes in 19% lower.
Where these numbers come from
The heating and cooling degree days behind this estimate — 2,378 HDD and 1,977 CDD (base 65°F, 1991-2020 normals) — come from BEAUFORT MICHAEL J SMITH FLD, NC US, the nearest NOAA station with published normals, 11.2 miles from Carteret County's center. By total degree days, Carteret County sits at the 8th percentile nationally. One local detail the R-value alone won't tell you: Carteret County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $127/year saved — roughly 12.7 years to break even. Call this borderline rather than a clear win.
Next steps for a Carteret County attic
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 Carteret County's estimated $946/year on the line.
Where these figures come from
Carteret 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.