Dawson County, MT Insulation Payback
Dawson County, MT: what topping up your attic actually costs
DOE classifies Dawson County as climate zone 6, cold — a real winter that drives most of the annual energy bill here. 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 $2,104 a year in heating and cooling — a payback around 1.7 years. That's about as fast as attic paybacks get.
Heating vs. cooling in Dawson County
The estimated savings split roughly $1,983/year heating, $121/year cooling. Out of every 100 US counties tracked here, Dawson County's savings potential beats roughly 86 of them. Within zone 6 specifically, it ranks 289th of 459 counties by estimated savings. Montana averages $2,182/year across the counties tracked here; Dawson County comes in 4% lower.
Dawson County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 7,417 HDD and 751 CDD (base 65°F, 1991-2020 normals) — come from GLENDIVE, MT US, the nearest NOAA station with published normals, 14 miles from Dawson County's center. That combined heating-and-cooling load ranks Dawson County 384th nationally by total degree days — the 88th percentile. Dawson County falls in DOE's moisture regime B (dry), a detail that affects vapor-barrier recommendations more than the R-value target itself.
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 $307/year saved — roughly 7.4 years to break even. That is a solid payback as home upgrades go.
Getting it done in Dawson County
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 Dawson County's estimated $2,104/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.