Polk County, OR Insulation Payback
Polk County, OR: what topping up your attic actually costs
Polk County, Oregon is zone 4 under DOE's climate map (Marine), which means temperate and damp most of the year, with neither heating nor cooling asking for much. 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 2.4 years at an estimated $1,449/year saved. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,418/year heating, $31/year cooling. Out of every 100 US counties tracked here, Polk County's savings potential beats roughly 49 of them. Within zone 4 specifically, it ranks 275th of 825 counties by estimated savings. Oregon averages $1,557/year across the counties tracked here; Polk County comes in 7% lower.
The climate data behind this
NOAA's FALLS CITY 2 SSW, OR US station, 5.2 miles from Polk County, supplies the 5,302 HDD and 193 CDD this estimate runs on. That combined heating-and-cooling load ranks Polk County 1911th nationally by total degree days — the 40th percentile. Polk County falls in DOE's moisture regime C (marine), a detail that affects vapor-barrier recommendations more than the R-value target itself.
If the attic isn't bare
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $211/year saved — roughly 10.8 years to break even. This one is a genuine toss-up, not a clear yes.
Getting it done in Polk 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 Polk 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.