Dane County, WI Insulation Payback
Is attic insulation worth it in Dane County, WI?
DOE classifies Dane County as climate zone 6, cold — winters that dominate the energy bill, with cooling a minor factor. 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 $2,000 a year in heating and cooling — a payback around 1.7 years. Few home upgrades pay back that quickly.
The breakdown behind the number
Heating accounts for about $1,897/year of that and cooling about $103/year — Dane County needs both. Nationally, Dane County ranks in the 82th percentile for insulation savings potential. Compared only against its own climate zone, Dane County places 395th out of 459. Against Wisconsin's own average of $2,200/year, Dane County runs 9% below that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 7,096 HDD and 640 CDD (base 65°F, 1991-2020 normals) — come from UW ARBORETUM - MADISON, WI US, the nearest NOAA station with published normals, 1.9 miles from Dane County's center. By total degree days, Dane County sits at the 83th percentile nationally. 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?
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. The math clears comfortably within a normal ownership horizon.
Next steps for a Dane 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 Dane County's estimated $2,000/year on the line.
Dane County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Dane 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.