Are Metal Roofs Energy Efficient?

If you are comparing a metal roof to another round of asphalt shingles, you are probably asking whether the higher upfront price buys you anything beyond looks. For your energy bills, it does. A metal roof reflects much of the sun's heat away from your home instead of absorbing it the way shingles do, so less heat reaches your attic and your air conditioner works less to keep up. Homeowners who choose cool metal roofing can lower cooling energy costs by as much as 20%, according to State Farm.

The U.S. Department of Energy defines energy efficiency as using less energy to get the same result, and a cool metal roof does exactly that for cooling. To judge the payoff, compare first cost against life cycle cost: a metal roof usually costs more up front, but because it can outlast two or three shingle roofs, it often becomes the least expensive roof you will ever own. Below, we cover how metal saves energy, why it holds up as an eco-friendly choice, how it works for a roof recover, and how it pairs with solar.

Is Metal an Energy-Efficient Roofing Material?

Yes. Metal roofing is highly energy efficient because it reflects the sun's heat up and away from the structure instead of soaking it up. Less absorbed heat means a cooler attic, a lighter cooling load, and lower utility bills. Two features push that efficiency further: cool roof pigments in the paint, and above-sheathing ventilation that lets trapped heat escape before it ever reaches your home.

How Cool Roof Pigments Reflect Heat

The coating on a metal panel does more than supply color. Because the roof is constantly exposed to the elements, the paint system has to match both long-term performance and the look you want. Metal roofing comes in a wide range of colors and finishes, and several paint systems are available, some better than others. Advances in paint technology let manufacturers add reflective pigments that build on the metal's already reflective surface. Metal coated this way is called cool metal roofing.

Cool metal roofing combines high solar reflectance with high thermal emittance. Reflectance is how much of the sun's energy bounces off the surface. Thermal emittance is how readily the panel releases the heat it does absorb. The two work together to keep heat out of the attic space and the rooms below, which lowers the interior temperature and the load on your cooling system. Rather than meeting a single reflectance threshold, cool roofing products are evaluated based on their solar reflectance and thermal emittance, with higher values generally providing greater heat-rejecting performance. 

Color choice matters here too. Lighter colors reflect more heat and keep the home cooler than dark colors. Light tones give you the best reflectivity, but even a darker metal roof reflects more than asphalt shingles do.

How Above-Sheathing Ventilation Works

Above-sheathing ventilation (ASV) is a second way a metal roof lowers cooling costs. ASV creates a vented air space between the metal panel and the substrate below it. Heat that would otherwise pass into the building moves through that channel and vents back into the outdoor air rather than being absorbed by the home.

The effect can be dramatic, especially where summers run hot. In the demonstration below, an attic protected by ASV and solar venting stayed only about 5 degrees above the outdoor air temperature. An attic under bare shingles ran close to 40 degrees hotter than the surrounding air. That gap is cooling load your air conditioner never has to carry.

McElroy Metal's painted Galvalume® panels come in a broad selection of cool-rated colors, including high-performance Kynar 500® PVDF finishes engineered to hold their reflectivity for decades, so choosing an energy-efficient roof never forces a compromise on how your home looks.

Is Metal an Environmentally Friendly Roofing Material?

Yes. Beyond the energy savings, metal is one of the more environmentally friendly roofing materials you can choose, because it lasts for decades and is fully recyclable at the end of its life. A long-lived roof means fewer replacements, less manufacturing energy, and far less waste sent to the landfill over the life of your home.

Lifespan is the foundation of that case. A metal roof can last 60 years or more with little maintenance. A service-life study from the Metal Construction Association reached a similar conclusion, finding that a Galvalume standing seam roof built today can be expected to exceed 60 years of service across a wide range of climates. Asphalt shingles, by contrast, are typically replaced every 15 to 30 years, so one metal roof can outlast two or three shingle roofs.

The material itself is recyclable. Steel is among the most recycled materials in North America, and a steel roof can be fully recycled when it is finally removed, according to the Steel Recycling Institute. Over the decades you own the home, choosing metal keeps tons of torn-off shingles out of landfills.

McElroy Metal builds its panels on Galvalume® steel, and as an employee-owned company, the people manufacturing the product have a direct stake in how it performs across that full multi-decade service life.

Is Metal a Good Choice for Recovering My Existing Roof?

Yes. Metal is one of the best materials for recovering an existing roof, and a recover is an inherently sustainable choice. Installing metal over a sound existing roof avoids tearing off and hauling away the old one, which trims labor, new materials, installation time, and landfill waste in a single step.

There is a comfort payoff as well. Leaving the existing shingles and substructure in place adds a layer of insulation between the metal and the living space, which helps hold down heating and cooling costs. A metal recover can protect the building for the next several decades with minimal upkeep.

McElroy Metal makes panels suited to both metal-over-shingle and metal-over-metal recover systems, and its technical team can help your contractor confirm the existing roof and structure are right for a recover before any work begins.

Is Metal a Good Roof for Solar Panels?

Yes. Metal is one of the best roofing surfaces for solar because many metal systems let installers mount the panels without drilling a single hole through the roof. That makes metal roofs a natural pairing with solar.

On a shingle roof, solar mounts are bolted straight through the roofing, creating dozens of penetrations and potential leak points. On a standing seam metal roof, mounting clamps grip the raised seams, so nothing penetrates the panel, and the roof and its warranty stay intact. The Metal Construction Association notes that standing seam systems allow solar to be mounted with zero roof penetration. Metal is also strong enough to carry the added weight, and because it lasts for decades, your roof will not need replacing partway through the life of the solar array.

McElroy Metal's standing seam systems, including 238T and Medallion-Lok, provide the raised-seam profile that clamp-style solar mounts are designed to attach to without penetrations.

Is a Metal Roof the Right Choice for Your Home?

If you want decades of lower cooling bills, minimal maintenance, and a roof that is recyclable at the end of its long life, metal earns a close look. The upfront cost runs higher than shingles, but the energy savings, longevity, and reduced upkeep often make it the more economical choice across the years you own your home.

To picture how a metal roof would look on your house, explore McElroy Metal's color and finish options, then talk with a local contractor about the right panel and paint system for your climate.

Since 1963, McElroy Metal has served the construction industry with quality products and dependable service. The employee-owned manufacturer is headquartered in Bossier City, Louisiana, with 14 manufacturing facilities across the United States.