Kootenai County, ID Insulation Payback
Kootenai County, ID: what topping up your attic actually costs
Kootenai County, Idaho is zone 5 under DOE's climate map (Cold), which means winters that dominate the energy bill, with cooling a minor factor. 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 2 years at an estimated $1,759/year saved. That's about as fast as attic paybacks get.
Heating vs. cooling in Kootenai County
The estimated savings split roughly $1,689/year heating, $70/year cooling. Out of every 100 US counties tracked here, Kootenai County's savings potential beats roughly 70 of them. Within zone 5 specifically, it ranks 370th of 745 counties by estimated savings. Idaho averages $1,995/year across the counties tracked here; Kootenai County comes in 12% lower.
Where these numbers come from
NOAA's COEUR D'ALENE, ID US station, 4.7 miles from Kootenai County, supplies the 6,317 HDD and 437 CDD this estimate runs on. By total degree days, Kootenai County sits at the 67th percentile nationally. Kootenai 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
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 $257/year saved (~8.9-year payback). This one is a genuine toss-up, not a clear yes.
Getting it done in Kootenai County
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $3,480 as a starting estimate for a Kootenai County job, not a quote. Expect at least a $600 minimum charge from most contractors.
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.