Williams County, ND Insulation Payback
Attic insulation payback for Williams County, ND
Williams County, North Dakota is zone 7 under DOE's climate map (Very Cold), which means a climate where the heating season stretches across most of the year. 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 1.4 years at an estimated $2,455/year saved. Hard to find a home improvement with a faster payback than this.
The breakdown behind the number
Of that, about $2,381/year comes from reduced heating and $73/year from reduced cooling load through the ceiling. Williams County beats 97% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 120 counties DOE places in zone 7, Williams County ranks 77th. Against North Dakota's own average of $2,496/year, Williams County runs 2% below that.
Williams County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 8,906 HDD and 457 CDD (base 65°F, 1991-2020 normals) — come from WILLISTON SLOULIN INTL AP, ND US, the nearest NOAA station with published normals, 14 miles from Williams County's center. Combined heating and cooling load puts Williams County in the 97th percentile of this 3,162-county dataset.
Already have some insulation?
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 $358/year saved (~6.4-year payback). Topping up the attic pays for itself here.
Next steps for a Williams 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 Williams County's estimated $2,455/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.