Franklin County, TX Insulation Payback
Franklin County attic insulation, by the numbers
DOE classifies Franklin County as climate zone 3, hot-humid — long, muggy summers and mild winters, where cooling dominates the energy bill. Its recommended attic R-value for bare joists is 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 $1,051 a year — payback in roughly 2.7 years. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $666 a year on the heating side, $385 on cooling. By estimated insulation savings, Franklin County lands in the 21th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Franklin County comes in 356th by savings. Texas averages $1,035/year across the counties tracked here; Franklin County comes in 2% higher.
Franklin County's actual weather, not a national average
NOAA's MT VERNON, TX US station, 1.4 miles from Franklin County, supplies the 2,511 HDD and 2,413 CDD this estimate runs on. By total degree days, Franklin County sits at the 24th percentile nationally. One local detail the R-value alone won't tell you: Franklin County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
If Franklin 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 $142/year — payback about 11.4 years. Call this borderline rather than a clear win.
Getting it done in Franklin County
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $2,820 as a starting estimate for a Franklin County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Franklin County's R-49 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-49 is the target here specifically.