Strafford County, NH Insulation Payback
Strafford County, NH: what topping up your attic actually costs
Strafford County, New Hampshire 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. 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 $1,897 a year — payback in roughly 1.8 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,816/year heating, $81/year cooling. Out of every 100 US counties tracked here, Strafford County's savings potential beats roughly 77 of them. Within zone 5 specifically, it ranks 153rd of 745 counties by estimated savings. New Hampshire averages $2,071/year across the counties tracked here; Strafford County comes in 8% lower.
The climate data behind this
The heating and cooling degree days behind this estimate — 6,790 HDD and 506 CDD (base 65°F, 1991-2020 normals) — come from ROCHESTER SKYHAVEN AP, NH US, the nearest NOAA station with published normals, 5.8 miles from Strafford County's center. By total degree days, Strafford County sits at the 77th percentile nationally. Strafford 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 Strafford 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 $277/year — payback about 8.2 years. This one is a genuine toss-up, not a clear yes.
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 Strafford County's estimated $1,897/year on the line.
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-60 is the target here specifically.