Lemhi County, ID Insulation Payback
Is attic insulation worth it in Lemhi County, ID?
Lemhi County sits in IECC climate zone 6 (Cold) — a real winter that drives most of the annual energy bill here. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to 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 1.6 years at an estimated $2,123/year saved. Few home upgrades pay back that quickly.
Where the savings come from
Heating accounts for about $2,076/year of that and cooling about $47/year — Lemhi County needs both. Nationally, Lemhi County ranks in the 87th percentile for insulation savings potential. Compared only against its own climate zone, Lemhi County places 275th out of 459. Against Idaho's own average of $1,995/year, Lemhi County runs 6% above that.
Lemhi County's actual weather, not a national average
Lemhi County's climate figures — 7,765 heating and 293 cooling degree days a year — are read from SALMON-KSRA, ID US, 16.9 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Lemhi County in the 86th percentile of this 3,162-county dataset. Its moisture regime is classified dry, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
If the attic isn't bare
If Lemhi 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 $310/year — payback about 7.4 years. The math clears comfortably within a normal ownership horizon.
Next steps for a Lemhi County attic
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 Lemhi County's estimated $2,123/year on the line.
Lemhi County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Lemhi County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.