Carbon County, WY Insulation Payback
Carbon County, WY: what topping up your attic actually costs
Carbon County, Wyoming is zone 6 under DOE's climate map (Cold), which means a real winter that drives most of the annual energy bill here. An uninsulated attic there should be built up to R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $2,220 a year in heating and cooling — a payback around 1.6 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $2,184/year heating, $36/year cooling. Out of every 100 US counties tracked here, Carbon County's savings potential beats roughly 91 of them. Within zone 6 specifically, it ranks 171st of 459 counties by estimated savings. Wyoming averages $2,161/year across the counties tracked here; Carbon County comes in 3% higher.
Where these numbers come from
The heating and cooling degree days behind this estimate — 8,168 HDD and 224 CDD (base 65°F, 1991-2020 normals) — come from RAWLINS MUNI AP, WY US, the nearest NOAA station with published normals, 15.4 miles from Carbon County's center. Combined heating and cooling load puts Carbon County in the 90th percentile of this 3,162-county dataset. Carbon County falls in DOE's moisture regime B (dry), a detail that affects vapor-barrier recommendations more than the R-value target itself.
The smaller top-up scenario
If Carbon County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $324/year — payback about 7 years. That is a solid payback as home upgrades go.
Next steps for a Carbon County attic
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Carbon 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-60 is the target here specifically.