Nez Perce County, ID Insulation Payback
Attic insulation payback for Nez Perce County, ID
DOE classifies Nez Perce County as climate zone 5, cold — cold enough that heating, not cooling, is what decides the bill. Its recommended attic R-value for bare joists is R-60. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 1.7 years at an estimated $2,042/year saved. Hard to find a home improvement with a faster payback than this.
Heating vs. cooling in Nez Perce County
Of that, about $2,019/year comes from reduced heating and $22/year from reduced cooling load through the ceiling. Nez Perce County beats 84% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 745 counties DOE places in zone 5, Nez Perce County ranks 25th. Against Idaho's own average of $1,995/year, Nez Perce County runs 2% above that.
Where these numbers come from
NOAA's WINCHESTER, ID US station, 9.3 miles from Nez Perce County, supplies the 7,552 HDD and 140 CDD this estimate runs on. By total degree days, Nez Perce County sits at the 82th percentile nationally. DOE also classifies Nez Perce County as moisture regime B (dry) - ask a local contractor whether that changes the vapor-barrier approach for this job.
Already have some insulation?
If Nez Perce 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 $298/year — payback about 7.7 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 Nez Perce County's estimated $2,042/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.