Hardeman County, TN Insulation Payback
Is attic insulation worth it in Hardeman County, TN?
Hardeman 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 2.3 years at an estimated $1,217/year saved. Few home upgrades pay back that quickly.
Where the savings come from
Heating accounts for about $954/year of that and cooling about $263/year — Hardeman County needs both. Nationally, Hardeman County ranks in the 32th percentile for insulation savings potential. Compared only against its own climate zone, Hardeman County places 79th out of 690. Against Tennessee's own average of $1,258/year, Hardeman County runs 3% below that.
Where these numbers come from
Hardeman County's climate figures — 3,595 heating and 1,652 cooling degree days a year — are read from BOLIVAR WTR WKS, TN US, 3 miles away, NOAA's nearest 1991-2020 normals station. By total degree days, Hardeman County sits at the 33th percentile nationally. Its moisture regime is classified humid, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
The smaller top-up scenario
A shallower starting point changes the math: with R-11 already down, only the gap to R-38 needs filling, at roughly $1,620 for an estimated $164/year saved (~9.9-year payback). Whether that is worth it depends on how long you plan to stay.
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 $2,820 figure above as a planning number for Hardeman County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Hardeman County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Hardeman County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.