Union County, TN Insulation Payback
Union County attic insulation, by the numbers
Union County sits in IECC climate zone 4 (Mixed-Humid) — real heating and real cooling seasons both, roughly balanced across the year. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to R-60. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.6 years at an estimated $1,329/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,172 a year on the heating side, $156 on cooling. By estimated insulation savings, Union County lands in the 41th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Union County comes in 525th by savings. Tennessee averages $1,258/year across the counties tracked here; Union County comes in 6% higher.
Union County's actual weather, not a national average
NOAA's NORRIS, TN US station, 13.4 miles from Union County, supplies the 4,385 HDD and 974 CDD this estimate runs on. By total degree days, Union County sits at the 36th percentile nationally. One local detail the R-value alone won't tell you: Union 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-49 runs about $2,280 for about $194/year saved — roughly 11.8 years to break even. Call this borderline rather than a clear win.
Quotes and materials for this job
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 Union County's estimated $1,329/year on the line.
Where these figures come from
Union 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.