Sierra County, NM Insulation Payback
Sierra County attic insulation, by the numbers
DOE classifies Sierra County as climate zone 4, mixed-dry — big seasonal swings - a dry hot summer, then a real winter cold snap. Its recommended attic R-value for bare joists is 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 $1,097 a year — payback in roughly 3.2 years. Topping up the attic pays for itself here.
Heating vs. cooling in Sierra County
Split it out and it's roughly $742 a year on the heating side, $355 on cooling. By estimated insulation savings, Sierra County lands in the 24th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Sierra County comes in 817th by savings. New Mexico averages $1,423/year across the counties tracked here; Sierra County comes in 23% lower.
Sierra County's actual weather, not a national average
NOAA's ELEPHANT BUTTE DAM, NM US station, 1.9 miles from Sierra County, supplies the 2,774 HDD and 2,209 CDD this estimate runs on. That combined heating-and-cooling load ranks Sierra County 2366th nationally by total degree days — the 25th percentile. One local detail the R-value alone won't tell you: Sierra County sits in moisture regime B (dry), which can affect the vapor-barrier choice.
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 $160/year saved — roughly 14.3 years to break even. Call this borderline rather than a clear win.
Quotes and materials for this job
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 Sierra County's estimated $1,097/year on the line.
Where these figures come from
Sierra 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.