Denver County, CO Insulation Payback
Is attic insulation worth it in Denver County, CO?
Denver County, Colorado is zone 5 under DOE's climate map (Cold), which means cold enough that heating, not cooling, is what decides the bill. An uninsulated attic there should be built up to R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $1,672 a year in heating and cooling — a payback around 2.1 years. Few home upgrades pay back that quickly.
Heating vs. cooling in Denver County
Heating accounts for about $1,541/year of that and cooling about $131/year — Denver County needs both. Nationally, Denver County ranks in the 64th percentile for insulation savings potential. Compared only against its own climate zone, Denver County places 531st out of 745. Against Colorado's own average of $2,043/year, Denver County runs 18% below that.
Where these numbers come from
The heating and cooling degree days behind this estimate — 5,765 HDD and 813 CDD (base 65°F, 1991-2020 normals) — come from DENVER-STAPLETON, CO US, the nearest NOAA station with published normals, 0.6 miles from Denver County's center. By total degree days, Denver County sits at the 63th percentile nationally. Its moisture regime is classified dry, which matters for whether the attic needs a vapor retarder as part of the job — worth asking a contractor about locally.
Already have some insulation?
If Denver 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 $244/year — payback about 9.3 years. Whether that is worth it depends on how long you plan to stay.
Getting it done in Denver County
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 Denver County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Denver County's numbers, sourced
The methodology guide lists exactly which DOE and NOAA sources feed Denver County's numbers, and where the cost assumptions come from. See the DIY vs. contractor guide for whether a job this size is realistic to do yourself.