Dukes County, MA Insulation Payback
Attic insulation payback for Dukes County, MA
Dukes County, Massachusetts 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. 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 $1,628 a year in heating and cooling — a payback around 2.1 years. Hard to find a home improvement with a faster payback than this.
Where the savings come from
Of that, about $1,556/year comes from reduced heating and $72/year from reduced cooling load through the ceiling. Dukes 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, Dukes County ranks 605th. Against Massachusetts's own average of $1,728/year, Dukes County runs 6% below that.
Where these numbers come from
Dukes County's climate figures — 5,819 heating and 449 cooling degree days a year — are read from VINEYARD HAVEN AP, MA US, 4.6 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Dukes County 1350th nationally by total degree days — the 57th percentile. DOE also classifies Dukes County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
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 $237/year saved (~9.6-year payback). It is close - the payback only just fits a reasonable timeframe.
Next steps for a Dukes County attic
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Dukes County's estimated $1,628/year on the line.
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.