Lincoln County, TN Insulation Payback
Lincoln County attic insulation, by the numbers
DOE classifies Lincoln County as climate zone 4, 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-60. For an attic around 1,000 square feet, closing the gap from R-2 to R-60 costs around $3,480 and saves an estimated $1,151 a year — payback in roughly 3 years. Topping up the attic pays for itself here.
The breakdown behind the number
Split it out and it's roughly $899 a year on the heating side, $251 on cooling. By estimated insulation savings, Lincoln County lands in the 28th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Lincoln County comes in 790th by savings. Tennessee averages $1,258/year across the counties tracked here; Lincoln County comes in 9% lower.
The climate data behind this
Lincoln County's climate figures — 3,363 heating and 1,565 cooling degree days a year — are read from FAYETTEVILLE WTP, TN US, 3 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Lincoln County 2409th nationally by total degree days — the 24th percentile. One local detail the R-value alone won't tell you: Lincoln County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
A shallower starting point changes the math: with R-11 already down, only the gap to R-49 needs filling, at roughly $2,280 for an estimated $168/year saved (~13.6-year payback). Call this borderline rather than a clear win.
Getting it done in Lincoln County
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Lincoln County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Lincoln County's R-60 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-60 is the target here specifically.