Smyth County, VA Insulation Payback
Attic insulation payback for Smyth County, VA
Smyth County, Virginia is zone 4 under DOE's climate map (Mixed-Humid), which means real heating and real cooling seasons both, roughly balanced across the year. 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 2.5 years at an estimated $1,416/year saved. Hard to find a home improvement with a faster payback than this.
Heating vs. cooling in Smyth County
Of that, about $1,288/year comes from reduced heating and $128/year from reduced cooling load through the ceiling. Smyth County beats 47% of the counties in this 3,162-county dataset on estimated insulation savings. Among the 825 counties DOE places in zone 4, Smyth County ranks 353rd. Against Virginia's own average of $1,342/year, Smyth County runs 6% above that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 4,818 HDD and 796 CDD (base 65°F, 1991-2020 normals) — come from SALTVILLE 1N, VA US, the nearest NOAA station with published normals, 13.2 miles from Smyth County's center. That combined heating-and-cooling load ranks Smyth County 1820th nationally by total degree days — the 42th percentile. DOE also classifies Smyth County as moisture regime A (humid) - ask a local contractor whether that changes the vapor-barrier approach for this job.
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 $207/year saved (~11-year payback). It is close - the payback only just fits a reasonable timeframe.
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 Smyth County's estimated $1,416/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.