Standard dark asphalt shingles absorb 80 to 95 percent of solar radiation that strikes them. On a sunny summer day, this can drive roof surface temperatures to 150°F or higher — heat that transfers into the attic and eventually into the living space, creating significant additional cooling load for your HVAC system.

According to the U.S. Department of Energy, space cooling accounts for roughly 12 percent of total residential energy expenditure nationally — and in hot, sunny regions, the proportion is considerably higher. Roof-related heat gain is a significant contributor to this cooling demand.

How ENERGY STAR Cool-Roof Technology Works

Cool-Roof technology — as certified by the ENERGY STAR program — works through two mechanisms: solar reflectance and thermal emittance.

•       Solar reflectance: The coating reflects a significant portion of incoming solar radiation rather than absorbing it, reducing the amount of heat that enters the roof assembly.

•       Thermal emittance: Absorbed heat is released from the roof surface quickly rather than being retained and transferred into the attic.

ENERGY STAR certification requires third-party testing and verification of both reflectance and emittance values. ABC Seamless steel roofing meets the ENERGY STAR specification — which means the performance is validated, not marketing language.

What the Savings Look Like

The magnitude of energy savings from Cool-Roof technology depends on several factors: your climate (the hotter and sunnier, the greater the benefit), your attic insulation levels (lower insulation = more benefit from reduced heat gain), your cooling system type, and your utility rates.

The EPA and Department of Energy have documented that ENERGY STAR-qualified cool roofs can reduce peak cooling demand by 10 to 15 percent in appropriate climates — which translates to meaningfully lower energy bills during the cooling season. In high-cooling-demand regions (Southwest, Southeast, Gulf Coast), the savings are proportionally more significant than in northern climates with short summers.

Beyond Cooling: Winter Energy Performance

A common concern about reflective roofing is that it might increase heating costs in cold climates by reflecting away solar heat that would otherwise contribute to warming the home. In practice, this concern is largely theoretical. In cold climates, most of the heating season occurs when the sun angle is low and solar intensity is reduced — making the reflective benefit minimal. The thermal performance of the roofing system is dominated by the insulation in the attic assembly, not the roof surface reflectivity. Cool-Roof technology provides net energy benefits in essentially all climates when properly insulated attic assemblies are present.

The Additional Benefit of Foam-Backed Insulation

ABC Seamless siding is available with a foam-backed insulation option that reduces air infiltration through the wall assembly — complementing the roof's thermal performance. When a home's exterior is upgraded as a coordinated system — Cool-Roof steel roofing above, insulated steel siding on the walls — the combined reduction in heat gain and air infiltration can deliver meaningful whole-home energy improvements.