Graham County, AZ Insulation Payback
Graham County, AZ: what topping up your attic actually costs
Graham County, Arizona 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. 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 2.6 years at an estimated $1,075/year saved. That's about as fast as attic paybacks get.
Where the savings come from
The estimated savings split roughly $688/year heating, $387/year cooling. Out of every 100 US counties tracked here, Graham County's savings potential beats roughly 22 of them. Within zone 3 specifically, it ranks 299th of 690 counties by estimated savings. Arizona averages $1,149/year across the counties tracked here; Graham County comes in 6% lower.
Where these numbers come from
The heating and cooling degree days behind this estimate — 2,592 HDD and 2,431 CDD (base 65°F, 1991-2020 normals) — come from FT THOMAS 2 SW, AZ US, the nearest NOAA station with published normals, 8.2 miles from Graham County's center. That combined heating-and-cooling load ranks Graham County 2318th nationally by total degree days — the 27th percentile. Graham County falls in DOE's moisture regime B (dry), a detail that affects vapor-barrier recommendations more than the R-value target itself.
Already have some insulation?
A shallower starting point changes the math: with R-11 already down, only the gap to R-38 needs filling, at roughly $1,620 for an estimated $145/year saved (~11.2-year payback). This one is a genuine toss-up, not a clear yes.
Next steps for a Graham County attic
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 Graham County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-49 is the target here specifically.