Union County, NJ Insulation Payback
Union County, NJ: what topping up your attic actually costs
Union County, New Jersey is zone 4 under DOE's climate map (Mixed-Humid), which means a genuine mix of cold winters and humid summers, with neither one dominating the bill. 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 $1,479 a year — payback in roughly 2.4 years. That's about as fast as attic paybacks get.
The breakdown behind the number
The estimated savings split roughly $1,298/year heating, $180/year cooling. Out of every 100 US counties tracked here, Union County's savings potential beats roughly 52 of them. Within zone 4 specifically, it ranks 210th of 825 counties by estimated savings. New Jersey averages $1,541/year across the counties tracked here; Union County comes in 4% lower.
Union County's actual weather, not a national average
NOAA's CRANFORD, NJ US station, 0.9 miles from Union County, supplies the 4,856 HDD and 1,123 CDD this estimate runs on. By total degree days, Union County sits at the 51th percentile nationally. Union 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
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 $216/year saved (~10.6-year payback). This one is a genuine toss-up, not a clear yes.
Quotes and materials for this job
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 Union 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.