Bay County, MI Insulation Payback
Attic insulation payback for Bay County, MI
Bay County, Michigan is zone 5 under DOE's climate map (Cold), which means winters that dominate the energy bill, with cooling a minor factor. An uninsulated attic there should be built up to R-60. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 1.8 years at an estimated $1,963/year saved. Hard to find a home improvement with a faster payback than this.
Heating vs. cooling in Bay County
Of that, about $1,879/year comes from reduced heating and $84/year from reduced cooling load through the ceiling. Bay County beats 80% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 745 counties DOE places in zone 5, Bay County ranks 80th. Against Michigan's own average of $2,064/year, Bay County runs 5% below that.
Bay County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 7,027 HDD and 524 CDD (base 65°F, 1991-2020 normals) — come from AUBURN 2NE, MI US, the nearest NOAA station with published normals, 5.5 miles from Bay County's center. Combined heating and cooling load puts Bay County in the 80th percentile of this 3,162-county dataset. DOE also classifies Bay County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
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 $286/year saved (~8-year payback). Topping up the attic pays for itself here.
Getting it done in Bay 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 Bay County's estimated $1,963/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.