Knox County, TX Insulation Payback
Is attic insulation worth it in Knox County, TX?
Knox County, Texas is zone 3 under DOE's climate map (Hot-Dry), which means scorching, dry summers where heat radiating straight through the roof does most of the damage. An uninsulated attic there should be built up to R-49. For an attic around 1,000 square feet, closing the gap from R-2 to R-49 costs around $2,820 and saves an estimated $1,167 a year — payback in roughly 2.4 years. Few home upgrades pay back that quickly.
Where the savings come from
Heating accounts for about $775/year of that and cooling about $391/year — Knox County needs both. Nationally, Knox County ranks in the 29th percentile for insulation savings potential. Compared only against its own climate zone, Knox County places 134th out of 690. Against Texas's own average of $1,035/year, Knox County runs 13% above that.
Knox County's actual weather, not a national average
NOAA's TRUSCOTT 3 W, TX US station, 12.6 miles from Knox County, supplies the 2,922 HDD and 2,456 CDD this estimate runs on. By total degree days, Knox County sits at the 37th percentile nationally. Its moisture regime is classified dry, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
If the attic isn't bare
If Knox County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-38. That smaller top-up costs around $1,620 and saves an estimated $157/year — payback about 10.3 years. Whether that is worth it depends on how long you plan to stay.
Next steps for a Knox 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 Knox County's estimated $1,167/year on the line.
Knox County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Knox 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.