Cumberland County, ME Insulation Payback
Cumberland County attic insulation, by the numbers
DOE classifies Cumberland County as climate zone 6, cold — a real winter that drives most of the annual energy bill here. Its recommended attic R-value for bare joists is 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 1.8 years at an estimated $1,979/year saved. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $1,915 a year on the heating side, $64 on cooling. By estimated insulation savings, Cumberland County lands in the 81th percentile nationally. Zone 6 alone covers 459 counties in this dataset, and Cumberland County comes in 410th by savings. Maine averages $2,159/year across the counties tracked here; Cumberland County comes in 8% lower.
The climate data behind this
Cumberland County's climate figures — 7,163 heating and 396 cooling degree days a year — are read from GRAY, ME US, 6.9 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Cumberland County in the 80th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Cumberland County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $289/year saved — roughly 7.9 years to break even. Worth doing on the numbers alone.
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 Cumberland County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Cumberland County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.