Henry County, TN Insulation Payback
Is attic insulation worth it in Henry County, TN?
Henry 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. 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 $1,300 a year in heating and cooling — a payback around 2.7 years. Few home upgrades pay back that quickly.
The breakdown behind the number
Heating accounts for about $1,064/year of that and cooling about $236/year — Henry County needs both. Nationally, Henry County ranks in the 39th percentile for insulation savings potential. Compared only against its own climate zone, Henry County places 582nd out of 825. Against Tennessee's own average of $1,258/year, Henry County runs 3% above that.
The climate data behind this
The heating and cooling degree days behind this estimate — 3,978 HDD and 1,471 CDD (base 65°F, 1991-2020 normals) — come from PARIS 2 SE, TN US, the nearest NOAA station with published normals, 2.6 miles from Henry County's center. Combined heating and cooling load puts Henry County in the 39th percentile of this 3,162-county dataset. 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
If Henry County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $190/year — payback about 12 years. Whether that is worth it depends on how long you plan to stay.
Getting it done in Henry 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 Henry County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Henry County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Henry 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.