Big Horn County, WY Insulation Payback
Attic insulation payback for Big Horn County, WY
DOE classifies Big Horn County as climate zone 6, cold — cold enough that heating, not cooling, is what decides the bill. Its recommended attic R-value for bare joists is R-60. For an attic around 1,000 square feet, closing the gap from R-2 to R-60 costs around $3,480 and saves an estimated $2,185 a year — payback in roughly 1.6 years. Hard to find a home improvement with a faster payback than this.
Heating vs. cooling in Big Horn County
Of that, about $2,091/year comes from reduced heating and $93/year from reduced cooling load through the ceiling. Big Horn County beats 90% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 459 counties DOE places in zone 6, Big Horn County ranks 201st. Against Wyoming's own average of $2,161/year, Big Horn County runs 1% above that.
Big Horn County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 7,822 HDD and 582 CDD (base 65°F, 1991-2020 normals) — come from GREYBULL, WY US, the nearest NOAA station with published normals, 3.8 miles from Big Horn County's center. Combined heating and cooling load puts Big Horn County in the 90th percentile of this 3,162-county dataset. DOE also classifies Big Horn County as moisture regime B (dry) - ask a local contractor whether that changes the vapor-barrier approach for this job.
If the attic isn't bare
If Big Horn 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 $319/year — payback about 7.2 years. Topping up the attic pays for itself here.
Quotes and materials for this job
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Big Horn County's estimated $2,185/year on the line.
More on how this was built
Nothing here is a guess: the methodology guide names the DOE climate map and NOAA station data behind every number on this page. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.