Ontonagon County, MI Insulation Payback
Ontonagon County attic insulation, by the numbers
Ontonagon County sits in IECC climate zone 7 (Very Cold) — winters long and harsh enough that heating is essentially the entire equation. For a currently uninsulated attic, DOE and ENERGY STAR recommend building 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 $2,257 a year in heating and cooling — a payback around 1.5 years. Topping up the attic pays for itself fast here.
The breakdown behind the number
Split it out and it's roughly $2,200 a year on the heating side, $57 on cooling. By estimated insulation savings, Ontonagon County lands in the 92th percentile nationally. Zone 7 alone covers 120 counties in this dataset, and Ontonagon County comes in 110th by savings. Michigan averages $2,064/year across the counties tracked here; Ontonagon County comes in 9% higher.
Ontonagon County's actual weather, not a national average
Ontonagon County's climate figures — 8,229 heating and 354 cooling degree days a year — are read from ONTONAGON 6 SE, MI US, 3.3 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Ontonagon County in the 92th percentile of this 3,162-county dataset.
If the attic isn't bare
If Ontonagon County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $329/year — payback about 6.9 years. Worth doing on the numbers alone.
Next steps for a Ontonagon 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 Ontonagon County's estimated $2,257/year on the line.
Where these figures come from
Ontonagon County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.