Lewis County, MO Insulation Payback
Is attic insulation worth it in Lewis County, MO?
Lewis County, Missouri is zone 5 under DOE's climate map (Cold), which means a real winter that drives most of the annual energy bill here. An uninsulated attic there should be built 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 $1,667 a year in heating and cooling — a payback around 2.1 years. Few home upgrades pay back that quickly.
Heating vs. cooling in Lewis County
Heating accounts for about $1,495/year of that and cooling about $172/year — Lewis County needs both. Nationally, Lewis County ranks in the 64th percentile for insulation savings potential. Compared only against its own climate zone, Lewis County places 540th out of 745. Against Missouri's own average of $1,534/year, Lewis County runs 9% above that.
The climate data behind this
NOAA's STEFFENVILLE, MO US station, 11.5 miles from Lewis County, supplies the 5,592 HDD and 1,070 CDD this estimate runs on. Combined heating and cooling load puts Lewis County in the 65th percentile of this 3,162-county dataset. Its moisture regime is classified humid, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
The smaller top-up scenario
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 $243/year saved (~9.4-year payback). Whether that is worth it depends on how long you plan to stay.
Quotes and materials for this job
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 Lewis County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Lewis County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Lewis County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.