Cook County, MN Insulation Payback
Cook County attic insulation, by the numbers
Cook County sits in IECC climate zone 7 (Very Cold) — a climate where the heating season stretches across most of the year. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to 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 $2,498 a year in heating and cooling — a payback around 1.4 years. Topping up the attic pays for itself fast here.
Heating vs. cooling in Cook County
Split it out and it's roughly $2,489 a year on the heating side, $8 on cooling. By estimated insulation savings, Cook County lands in the 97th percentile nationally. Zone 7 alone covers 120 counties in this dataset, and Cook County comes in 66th by savings. Minnesota averages $2,366/year across the counties tracked here; Cook County comes in 6% higher.
Where these numbers come from
Cook County's climate figures — 9,310 heating and 51 cooling degree days a year — are read from GRAND MARAIS, MN US, 0.8 miles away, NOAA's nearest 1991-2020 normals station. By total degree days, Cook County sits at the 97th percentile nationally.
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 $364/year saved — roughly 6.3 years to break even. Worth doing on the numbers alone.
Next steps for a Cook County attic
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Cook County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Cook County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.