Grays Harbor County, WA Insulation Payback
Grays Harbor County, WA: what topping up your attic actually costs
Grays Harbor County, Washington 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. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $1,350 a year in heating and cooling — a payback around 2.6 years. That's about as fast as attic paybacks get.
Where the savings come from
The estimated savings split roughly $1,341/year heating, $9/year cooling. Out of every 100 US counties tracked here, Grays Harbor County's savings potential beats roughly 42 of them. Within zone 4 specifically, it ranks 484th of 825 counties by estimated savings. Washington averages $1,583/year across the counties tracked here; Grays Harbor County comes in 15% lower.
Grays Harbor County's actual weather, not a national average
NOAA's ABERDEEN, WA US station, 10.1 miles from Grays Harbor County, supplies the 5,017 HDD and 53 CDD this estimate runs on. By total degree days, Grays Harbor County sits at the 28th percentile nationally. Grays Harbor County falls in DOE's moisture regime C (marine), a detail that affects vapor-barrier recommendations more than the R-value target itself.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $197/year saved — roughly 11.6 years to break even. This one is a genuine toss-up, not a clear yes.
Getting it done in Grays Harbor County
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Grays Harbor County, not a bid - contractors typically charge a $600 minimum regardless of job size.
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.