Hill County, MT Insulation Payback
Is attic insulation worth it in Hill County, MT?
DOE classifies Hill 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. 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 $2,371 a year — payback in roughly 1.5 years. Few home upgrades pay back that quickly.
The breakdown behind the number
Heating accounts for about $2,332/year of that and cooling about $40/year — Hill County needs both. Nationally, Hill County ranks in the 95th percentile for insulation savings potential. Compared only against its own climate zone, Hill County places 49th out of 459. Against Montana's own average of $2,182/year, Hill County runs 9% above that.
The climate data behind this
Hill County's climate figures — 8,720 heating and 247 cooling degree days a year — are read from GILDFORD, MT US, 10.1 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Hill County 169th nationally by total degree days — the 95th percentile. Its moisture regime is classified dry, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
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 $346/year saved — roughly 6.6 years to break even. The math clears comfortably within a normal ownership horizon.
Getting it done in Hill County
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 Hill County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Hill County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Hill 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.