Cass County, MN Insulation Payback
Cass County, MN: what topping up your attic actually costs
Cass County, Minnesota is zone 7 under DOE's climate map (Very Cold), which means winters long and harsh enough that heating is essentially the entire equation. 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 $2,417 a year — payback in roughly 1.4 years. That's about as fast as attic paybacks get.
Where the savings come from
The estimated savings split roughly $2,354/year heating, $64/year cooling. Out of every 100 US counties tracked here, Cass County's savings potential beats roughly 96 of them. Within zone 7 specifically, it ranks 88th of 120 counties by estimated savings. Minnesota averages $2,366/year across the counties tracked here; Cass County comes in 2% higher.
The climate data behind this
Cass County's climate figures — 8,802 heating and 398 cooling degree days a year — are read from DEEP PORTAGE, MN US, 4.4 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Cass County in the 96th percentile of this 3,162-county dataset.
If the attic isn't bare
A shallower starting point changes the math: with R-11 already down, only the gap to R-49 needs filling, at roughly $2,280 for an estimated $353/year saved (~6.5-year payback). That is a solid payback as home upgrades go.
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 Cass County's estimated $2,417/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.