Boundary County, ID Insulation Payback
Boundary County attic insulation, by the numbers
Boundary County, Idaho 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. 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 1.9 years at an estimated $1,842/year saved. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $1,785 a year on the heating side, $57 on cooling. By estimated insulation savings, Boundary County lands in the 75th percentile nationally. Zone 6 alone covers 459 counties in this dataset, and Boundary County comes in 451st by savings. Idaho averages $1,995/year across the counties tracked here; Boundary County comes in 8% lower.
The climate data behind this
NOAA's BONNERS FERRY, ID US station, 11.2 miles from Boundary County, supplies the 6,674 HDD and 355 CDD this estimate runs on. Combined heating and cooling load puts Boundary County in the 72th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Boundary County sits in moisture regime B (dry), which can affect the vapor-barrier choice.
The smaller top-up scenario
A shallower starting point changes the math: with R-11 already down, only the gap to R-49 needs filling, at roughly $2,280 for an estimated $269/year saved (~8.5-year payback). Call this borderline rather than a clear win.
Next steps for a Boundary 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 Boundary County's estimated $1,842/year on the line.
Where these figures come from
Boundary County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.