Addison County, VT Insulation Payback
Is attic insulation worth it in Addison County, VT?
DOE classifies Addison County as climate zone 6, cold — cold enough that heating, not cooling, is what decides the bill. Its recommended attic R-value for bare joists is 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 $2,132 a year in heating and cooling — a payback around 1.6 years. Few home upgrades pay back that quickly.
Heating vs. cooling in Addison County
Heating accounts for about $2,060/year of that and cooling about $72/year — Addison County needs both. Nationally, Addison County ranks in the 88th percentile for insulation savings potential. Compared only against its own climate zone, Addison County places 260th out of 459. Against Vermont's own average of $2,179/year, Addison County runs 2% below that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 7,705 HDD and 446 CDD (base 65°F, 1991-2020 normals) — come from CORNWALL, VT US, the nearest NOAA station with published normals, 6.2 miles from Addison County's center. Combined heating and cooling load puts Addison County in the 88th percentile of this 3,162-county dataset. Its moisture regime is classified humid, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
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 $311/year saved (~7.3-year payback). The math clears comfortably within a normal ownership horizon.
Quotes and materials for this job
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 Addison County's estimated $2,132/year on the line.
Addison County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Addison County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.