The IRS Section 25C credit was renewed under the IRA and updated for
2026 implementation. For NAZ homeowners, the credit + utility rebates
+ actual cooling savings make light-colored roofs a clear winner —
when the rest of the spec is right.
Here's the full math.
What 25C pays in 2026
- 30 % of qualified material costs
- $1,200 annual cap for the building envelope (this is the roof bucket)
- Reset every calendar year — split projects to maximize
- Roof must meet ENERGY STAR cool-roof spec (specific products only)
ENERGY STAR cool-roof spec for 2026:
- Steep slope (>2:12): solar reflectance ≥ 0.20 initial, ≥ 0.15
after 3 years
- Low slope (≤2:12): solar reflectance ≥ 0.25 initial, ≥ 0.15
after 3 years
- Listed on the ENERGY STAR Certified Roof Products database
Cooling savings math (NAZ-specific)
At 4,500–5,500 ft elevation in Northern Arizona:
| Roof color | Avg attic temp at 95 °F outdoor |
|---|---|
| Black asphalt shingle | 168 °F |
| Dark brown tile | 158 °F |
| Medium beige shingle | 142 °F |
| Light gray shingle | 128 °F |
| White metal | 110 °F |
| White TPO membrane | 105 °F |
Cooling load on the AC unit scales with attic temperature roughly
linearly. A 35 °F drop in attic temp typically translates to:
- 12–18 % reduction in cooling kWh
- $180–$340/yr savings in NAZ (depends on home size + usage)
Sample stack — Prescott, 2,400 sq ft home
Cool roof spec: GAF Timberline HDZ Cool Series, "Pewter Gray" color
(cool-rated), 24 squares.
| Item | Amount |
|---|---|
| Material cost (cool shingle premium) | $4,400 |
| Total roof project | $14,800 |
| Section 25C credit (30 % × $4,400) | -$1,200 (capped) |
| APS Cool Roof Rebate | -$540 |
| Net out-of-pocket | $13,060 |
| Annual cooling savings | -$240/yr |
| Payback period | ~5 years |
Compare to dark shingle: $13,200 install, no credits, no rebates,
no cooling savings. The cool roof is a clear winner once payback hits
around year 5.
What products qualify (NAZ availability)
Asphalt shingle (cool lines)
- GAF Timberline HDZ Cool Series: 4 colors, ENERGY STAR rated
- Owens Corning Duration Cool Plus: 6 colors, all ENERGY STAR
- CertainTeed Landmark Solaris: 8 colors, ENERGY STAR
- Atlas Pinnacle Pristine: 5 colors
Metal
- Most light/cool color standing seam: PVDF Kynar finishes
(Galvalume base) qualify in light colors
- Stone-coated steel: Decra, Boral light colors
Tile
- Concrete tile: Specific Eagle and Boral colors qualify (limited
palette in NAZ — usually buff, beige, light terracotta)
- Clay tile: Some natural clay colors qualify
Membrane (flat roofs)
- TPO: Standard white meets spec
- PVC: Standard white meets spec
- EPDM: Only specific "Eco-White" lines qualify
Many "cool-looking" colors don't meet ENERGY STAR spec. The credit
requires product listed on ENERGY STAR database, not visual
similarity. Get the manufacturer certification statement.
Documentation required for credit
- Manufacturer certification statement — required by IRS in 2026
- Receipt showing material cost separately from labor
- Form 5695 filed with your federal return
- Records kept for 3 years (audit window)
Your contractor should provide #1 and #2 at project completion. Don't
accept a lump-sum invoice — get a line-itemed bill that breaks out
qualifying material costs.
What's NOT covered
- Labor: only material cost qualifies for 25C
- Tear-off: not qualifying material
- Underlayment: separate item — only certain Class A radiant
barrier underlayment products qualify
- Vents and accessories: not qualifying
The "$1,200 cap on $4,000 of materials" math means a typical reroof
won't max the credit on roof alone. To max:
- Pair with insulation (separate envelope item, has its own cap)
- Pair with windows (separate cap)
- Pair with air sealing (separate cap)
Multi-year strategy
Because the credit resets annually, splitting a major envelope
project across years can extract more total credit:
| Year | Project | Credit |
|---|---|---|
| 2026 | Reroof (cool) | $1,200 |
| 2027 | Insulation upgrade + air sealing | $1,200 |
| 2028 | Windows (south-facing) | $1,200 |
Total: $3,600 federal credit + utility rebates. Compared to
everything-in-one-year at $1,200 cap.
When this strategy doesn't work
- Not enough federal tax bill: 25C is non-refundable. If you
owe less than $1,200 in federal tax, you cap at what you owe.
Retirees and very-low-income filers may not benefit.
- Solar planned in same year: Stack carefully — see our 25D guide
- Older home with insulation issues: A cool roof on a poorly
insulated home has limited effect. Address insulation first.
NAZ ENERGY STAR product lookups: https://www.energystar.gov/products/certified-products/detail/roof_products
Filter by manufacturer + product line for the certificate that
qualifies your install.
Match with a NAZ roofer who handles cool-roof installs through the
wizard.