Harrison County, MO Insulation Payback
Is attic insulation worth it in Harrison County, MO?
Harrison County, Missouri 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 2 years at an estimated $1,738/year saved. Few home upgrades pay back that quickly.
Where the savings come from
Heating accounts for about $1,564/year of that and cooling about $175/year — Harrison County needs both. Nationally, Harrison County ranks in the 68th percentile for insulation savings potential. Compared only against its own climate zone, Harrison County places 411th out of 745. Against Missouri's own average of $1,534/year, Harrison County runs 13% above that.
The climate data behind this
The heating and cooling degree days behind this estimate — 5,848 HDD and 1,087 CDD (base 65°F, 1991-2020 normals) — come from BETHANY, MO US, the nearest NOAA station with published normals, 6.4 miles from Harrison County's center. By total degree days, Harrison County sits at the 70th percentile nationally. 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
If Harrison County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $254/year — payback about 9 years. 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 Harrison County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Harrison County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Harrison 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.