Montgomery County, KS Insulation Payback
Montgomery County, KS: what topping up your attic actually costs
DOE classifies Montgomery County as climate zone 4, mixed-humid — a genuine mix of cold winters and humid summers, with neither one dominating the bill. 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 $1,405 a year — payback in roughly 2.5 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,145/year heating, $260/year cooling. Out of every 100 US counties tracked here, Montgomery County's savings potential beats roughly 46 of them. Within zone 4 specifically, it ranks 382nd of 825 counties by estimated savings. Kansas averages $1,594/year across the counties tracked here; Montgomery County comes in 12% lower.
Where these numbers come from
The heating and cooling degree days behind this estimate — 4,284 HDD and 1,618 CDD (base 65°F, 1991-2020 normals) — come from INDEPENDENCE, KS US, the nearest NOAA station with published normals, 4 miles from Montgomery County's center. Combined heating and cooling load puts Montgomery County in the 50th percentile of this 3,162-county dataset. Montgomery County falls in DOE's moisture regime A (humid), a detail that affects vapor-barrier recommendations more than the R-value target itself.
The smaller top-up scenario
If Montgomery 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 $205/year — payback about 11.1 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 Montgomery County's estimated $1,405/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.