Roane County, TN Insulation Payback
Roane County attic insulation, by the numbers
Roane County, Tennessee is zone 4 under DOE's climate map (Mixed-Humid), which means heating load in winter and cooling load in summer, both worth taking seriously here. An uninsulated attic there should be built up to R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $1,259 a year in heating and cooling — a payback around 2.8 years. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,025 a year on the heating side, $234 on cooling. By estimated insulation savings, Roane County lands in the 35th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Roane County comes in 668th by savings. Tennessee averages $1,258/year across the counties tracked here; Roane County comes in 0% higher.
The climate data behind this
NOAA's KINGSTON, TN US station, 0.7 miles from Roane County, supplies the 3,832 HDD and 1,460 CDD this estimate runs on. By total degree days, Roane County sits at the 34th percentile nationally. One local detail the R-value alone won't tell you: Roane 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-49 runs about $2,280 for about $184/year saved — roughly 12.4 years to break even. 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 $3,480 figure above as a planning number for Roane County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Roane 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.