Renville County, ND Insulation Payback
Renville County, ND: what topping up your attic actually costs
DOE classifies Renville County as climate zone 7, very cold — a climate where the heating season stretches across most of the year. 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 $2,698 a year — payback in roughly 1.3 years. That's about as fast as attic paybacks get.
Heating vs. cooling in Renville County
The estimated savings split roughly $2,658/year heating, $40/year cooling. Out of every 100 US counties tracked here, Renville County's savings potential beats roughly 99 of them. Within zone 7 specifically, it ranks 23rd of 120 counties by estimated savings. North Dakota averages $2,496/year across the counties tracked here; Renville County comes in 8% higher.
The climate data behind this
The heating and cooling degree days behind this estimate — 9,939 HDD and 249 CDD (base 65°F, 1991-2020 normals) — come from MOHALL, ND US, the nearest NOAA station with published normals, 7.6 miles from Renville County's center. By total degree days, Renville County sits at the 99th percentile nationally.
Already have some insulation?
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 $393/year saved (~5.8-year payback). That is a solid payback as home upgrades go.
Next steps for a Renville County attic
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Renville County, not a bid - contractors typically charge a $600 minimum regardless of job size.
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.