InsulationPayback

Fallon County, MT Insulation Payback

Fallon County, MT: what topping up your attic actually costs

Fallon County sits in IECC climate zone 6 (Cold) — cold enough that heating, not cooling, is what decides the bill. 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. That's about as fast as attic paybacks get.

Where the savings come from

The estimated savings split roughly $2,162/year heating, $95/year cooling. Out of every 100 US counties tracked here, Fallon County's savings potential beats roughly 92 of them. Within zone 6 specifically, it ranks 133rd of 459 counties by estimated savings. Montana averages $2,182/year across the counties tracked here; Fallon County comes in 3% higher.

Where these numbers come from

Fallon County's climate figures — 8,085 heating and 594 cooling degree days a year — are read from BAKER, MT US, 6.8 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Fallon County 238th nationally by total degree days — the 93th percentile. Fallon County falls in DOE's moisture regime B (dry), a detail that affects vapor-barrier recommendations more than the R-value target itself.

If the attic isn't bare

Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $329/year saved — roughly 6.9 years to break even. That is a solid payback as home upgrades go.

Next steps for a Fallon 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 Fallon County's estimated $2,257/year on the line.

Nothing here is a guess

Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-60 is the target here specifically.