Pinal County, AZ Insulation Payback
Pinal County attic insulation, by the numbers
Pinal County, Arizona is zone 2 under DOE's climate map (Hot-Dry), which means desert-dry heat for much of the year, with the attic taking the brunt of it. An uninsulated attic there should be built up to R-49. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-49 runs an estimated $2,820, and saves about $925 a year in heating and cooling — a payback around 3 years. Topping up the attic pays for itself here.
The breakdown behind the number
Split it out and it's roughly $307 a year on the heating side, $618 on cooling. By estimated insulation savings, Pinal County lands in the 11th percentile nationally. Zone 2 alone covers 233 counties in this dataset, and Pinal County comes in 27th by savings. Arizona averages $1,149/year across the counties tracked here; Pinal County comes in 19% lower.
Where these numbers come from
NOAA's FLORENCE, AZ US station, 8.2 miles from Pinal County, supplies the 1,157 HDD and 3,877 CDD this estimate runs on. By total degree days, Pinal County sits at the 27th percentile nationally. One local detail the R-value alone won't tell you: Pinal County sits in moisture regime B (dry), which can affect the vapor-barrier choice.
Already have some insulation?
If Pinal 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 $125/year — payback about 13 years. Call this borderline rather than a clear win.
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 Pinal County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Pinal 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.