Union County, NM Insulation Payback
Attic insulation payback for Union County, NM
Union County, New Mexico is zone 4 under DOE's climate map (Mixed-Dry), which means dry heat in summer giving way to a properly cold winter. An uninsulated attic there should be built up to R-60. For an attic around 1,000 square feet, closing the gap from R-2 to R-60 costs around $3,480 and saves an estimated $1,532 a year — payback in roughly 2.3 years. Hard to find a home improvement with a faster payback than this.
The breakdown behind the number
Of that, about $1,434/year comes from reduced heating and $97/year from reduced cooling load through the ceiling. Union County beats 55% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 825 counties DOE places in zone 4, Union County ranks 132nd. Against New Mexico's own average of $1,423/year, Union County runs 8% above that.
Union County's actual weather, not a national average
Union County's climate figures — 5,364 heating and 607 cooling degree days a year — are read from GRENVILLE, NM US, 10.8 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Union County 1548th nationally by total degree days — the 51th percentile. DOE also classifies Union County as moisture regime B (dry) - ask a local contractor whether that changes the vapor-barrier approach for this job.
The smaller top-up scenario
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-49. That smaller top-up costs around $2,280 and saves an estimated $223/year — payback about 10.2 years. It is close - the payback only just fits a reasonable timeframe.
Getting it done in Union County
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 Union County's estimated $1,532/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.