Mifflin County, PA Insulation Payback
Attic insulation payback for Mifflin County, PA
DOE classifies Mifflin County as climate zone 5, cold — a real winter that drives most of the annual energy bill here. Its recommended attic R-value for bare joists is R-60. For an attic around 1,000 square feet, closing the gap from R-2 to R-60 costs around $3,480 and saves an estimated $1,623 a year — payback in roughly 2.1 years. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $1,489/year comes from reduced heating and $134/year from reduced cooling load through the ceiling. Mifflin County beats 61% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 745 counties DOE places in zone 5, Mifflin County ranks 614th. Against Pennsylvania's own average of $1,724/year, Mifflin County runs 6% below that.
Mifflin County's actual weather, not a national average
NOAA's LEWISTOWN, PA US station, 4.5 miles from Mifflin County, supplies the 5,570 HDD and 832 CDD this estimate runs on. That combined heating-and-cooling load ranks Mifflin County 1268th nationally by total degree days — the 60th percentile. DOE also classifies Mifflin County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
If the attic isn't bare
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 $237/year saved (~9.6-year payback). It is close - the payback only just fits a reasonable timeframe.
Quotes and materials for this job
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 Mifflin 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.