Liberty County, MT Insulation Payback
Attic insulation payback for Liberty County, MT
Liberty County, Montana is zone 6 under DOE's climate map (Cold), which means cold enough that heating, not cooling, is what decides the bill. An uninsulated attic there should be built up to 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 $2,407 a year — payback in roughly 1.4 years. Hard to find a home improvement with a faster payback than this.
Heating vs. cooling in Liberty County
Of that, about $2,366/year comes from reduced heating and $41/year from reduced cooling load through the ceiling. Liberty County beats 96% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 459 counties DOE places in zone 6, Liberty County ranks 30th. Against Montana's own average of $2,182/year, Liberty County runs 10% above that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 8,848 HDD and 257 CDD (base 65°F, 1991-2020 normals) — come from CHESTER, MT US, the nearest NOAA station with published normals, 4.7 miles from Liberty County's center. By total degree days, Liberty County sits at the 96th percentile nationally. DOE also classifies Liberty County as moisture regime B (dry) - ask a local contractor whether that changes the vapor-barrier approach for this job.
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 $351/year saved — roughly 6.5 years to break even. Topping up the attic pays for itself here.
Quotes and materials for this job
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 Liberty County's estimated $2,407/year on the line.
More on how this was built
Nothing here is a guess: the methodology guide names the DOE climate map and NOAA station data behind every number on this page. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.