Mohave County, AZ Insulation Payback
Mohave County, AZ: what topping up your attic actually costs
Mohave County sits in IECC climate zone 3 (Hot-Dry) — scorching, dry summers where heat radiating straight through the roof does most of the damage. For a currently uninsulated attic, DOE and ENERGY STAR recommend building 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 $1,159 a year — payback in roughly 2.4 years. That's about as fast as attic paybacks get.
Where the savings come from
The estimated savings split roughly $681/year heating, $478/year cooling. Out of every 100 US counties tracked here, Mohave County's savings potential beats roughly 28 of them. Within zone 3 specifically, it ranks 150th of 690 counties by estimated savings. Arizona averages $1,149/year across the counties tracked here; Mohave County comes in 1% higher.
The climate data behind this
NOAA's MEADVIEW 1W, AZ US station, 27.4 miles from Mohave County, supplies the 2,565 HDD and 3,002 CDD this estimate runs on. That combined heating-and-cooling load ranks Mohave County 1857th nationally by total degree days — the 41th percentile. Mohave 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?
If Mohave 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 $156/year — payback about 10.4 years. This one is a genuine toss-up, not a clear yes.
Next steps for a Mohave 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 Mohave 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.