Robeson County, NC Insulation Payback
Robeson County attic insulation, by the numbers
Robeson County sits in IECC climate zone 3 (Mixed-Humid) — a genuine mix of cold winters and humid summers, with neither one dominating the bill. For a currently uninsulated attic, DOE and Energy Star recommend building 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 2.8 years at an estimated $1,025/year saved.
Topping up the attic pays for itself fast here.
Heating vs. cooling in Robeson County
Split it out and it's roughly $692 a year on the heating side, $333 on cooling. By estimated insulation savings, Robeson County lands in the 18th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Robeson County comes in 424th by savings. North Carolina averages $1,169/year across the counties tracked here; Robeson County comes in 12% lower.
The climate data behind this
NOAA's Lumberton Muni AP, NC US station, 3.2 miles from Robeson County, supplies the 2,609 HDD and 2,087 CDD this estimate runs on. That combined heating-and-cooling load ranks Robeson County 2645th nationally by total degree days — the 17th percentile. One local detail the R-value alone won't tell you: Robeson County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
If Robeson County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-38. That smaller top-up costs around $1,620 and saves an estimated $138/year — payback about 11.7 years. 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, so treat the $2,820 figure above as a planning number for Robeson County, not a bid. Worth getting quotes from at least two local contractors before committing - most charge a $600 minimum regardless of job size.
Where these figures come from
Robeson 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.