Grand Isle County, VT Insulation Payback
Attic insulation payback for Grand Isle County, VT
Grand Isle County sits in IECC climate zone 6 (Cold) — a real winter that drives most of the annual energy bill here. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to 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 $2,002 a year — payback in roughly 1.7 years. Hard to find a home improvement with a faster payback than this.
Heating vs. cooling in Grand Isle County
Of that, about $1,905/year comes from reduced heating and $97/year from reduced cooling load through the ceiling. Grand Isle County beats 82% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 459 counties DOE places in zone 6, Grand Isle County ranks 392nd. Against Vermont's own average of $2,179/year, Grand Isle County runs 8% below that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 7,126 HDD and 601 CDD (base 65°F, 1991-2020 normals) — come from CHAZY, NY US, the nearest NOAA station with published normals, 7 miles from Grand Isle County's center. By total degree days, Grand Isle County sits at the 82th percentile nationally. DOE also classifies Grand Isle 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
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $292/year saved — roughly 7.8 years to break even. Topping up the attic pays for itself here.
Quotes and materials for this job
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 Grand Isle County, not a bid - contractors typically charge a $600 minimum regardless of job size.
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.