Union County, MS Insulation Payback
Union County, MS: what topping up your attic actually costs
Union County sits in IECC climate zone 3 (Mixed-Humid) — real heating and real cooling seasons both, roughly balanced across the year. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to R-49. Going from R-2 to the recommended R-49 costs roughly $2,820 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.4 years at an estimated $1,194/year saved. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $932/year heating, $263/year cooling. Out of every 100 US counties tracked here, Union County's savings potential beats roughly 31 of them. Within zone 3 specifically, it ranks 103rd of 690 counties by estimated savings. Mississippi averages $1,022/year across the counties tracked here; Union County comes in 17% higher.
Where these numbers come from
The heating and cooling degree days behind this estimate — 3,511 HDD and 1,650 CDD (base 65°F, 1991-2020 normals) — come from HICKORY FLAT, MS US, the nearest NOAA station with published normals, 14 miles from Union County's center. That combined heating-and-cooling load ranks Union County 2208th nationally by total degree days — the 30th percentile. Union County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
If the attic isn't bare
If Union County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-38. That smaller top-up costs around $1,620 and saves an estimated $161/year — payback about 10.1 years. This one is a genuine toss-up, not a clear yes.
Next steps for a Union County attic
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $2,820 as a starting estimate for a Union County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Nothing here is a guess
Every figure on this page traces to DOE/IECC climate zones and NOAA degree-day normals, documented in the methodology guide. The guide to what R-value actually means explains why R-49 is the target here specifically.