Obion County, TN Insulation Payback
Obion County, TN: what topping up your attic actually costs
DOE classifies Obion 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. 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 $1,331 a year in heating and cooling — a payback around 2.6 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,086/year heating, $245/year cooling. Out of every 100 US counties tracked here, Obion County's savings potential beats roughly 41 of them. Within zone 4 specifically, it ranks 521st of 825 counties by estimated savings. Tennessee averages $1,258/year across the counties tracked here; Obion County comes in 6% higher.
The climate data behind this
Obion County's climate figures — 4,060 heating and 1,526 cooling degree days a year — are read from UNION CITY, TN US, 6.8 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Obion County 1842nd nationally by total degree days — the 42th percentile. Obion County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
If the attic isn't bare
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 $194/year saved (~11.7-year payback). This one is a genuine toss-up, not a clear yes.
Next steps for a Obion 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 Obion County's estimated $1,331/year on the line.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-60 is the target here specifically.