Pierce County, WA Insulation Payback
Attic insulation payback for Pierce County, WA
DOE classifies Pierce County as climate zone 4, marine — temperate and damp most of the year, with neither heating nor cooling asking for much. Its recommended attic R-value for bare joists is 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 $1,462/year saved. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $1,443/year comes from reduced heating and $19/year from reduced cooling load through the ceiling. Pierce County beats 50% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 825 counties DOE places in zone 4, Pierce County ranks 256th. Against Washington's own average of $1,583/year, Pierce County runs 8% below that.
Pierce County's actual weather, not a national average
Pierce County's climate figures — 5,397 heating and 120 cooling degree days a year — are read from MCMILLIN RSVR, WA US, 7.6 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Pierce County 1891st nationally by total degree days — the 40th percentile. DOE also classifies Pierce County as moisture regime C (marine) - ask a local contractor whether that changes the vapor-barrier approach for this job.
Already have some insulation?
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 $213/year saved (~10.7-year payback). It is close - the payback only just fits a reasonable timeframe.
Next steps for a Pierce County attic
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 Pierce County job, not a quote. Expect at least a $600 minimum charge from most contractors.
More on how this was built
Nothing here is a guess: the methodology guide names the DOE climate map and NOAA station data behind every number on this page. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.