Greene County, AL Insulation Payback
Greene County attic insulation, by the numbers
DOE classifies Greene County as climate zone 3, mixed-humid — real heating and real cooling seasons both, roughly balanced across the year. Its recommended attic R-value for bare joists is 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 2.7 years at an estimated $1,031/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $691 a year on the heating side, $340 on cooling. By estimated insulation savings, Greene County lands in the 19th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Greene County comes in 404th by savings. Alabama averages $1,001/year across the counties tracked here; Greene County comes in 3% higher.
Where these numbers come from
NOAA's GAINESVILLE LOCK, AL US station, 9.9 miles from Greene County, supplies the 2,606 HDD and 2,131 CDD this estimate runs on. By total degree days, Greene County sits at the 18th percentile nationally. One local detail the R-value alone won't tell you: Greene County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
Already have a few inches up there? Topping R-11 up to R-38 runs about $1,620 for about $139/year saved — roughly 11.7 years to break even. Call this borderline rather than a clear win.
Getting it done in Greene County
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 Greene County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Greene 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.