Content provided by the Metal Roofing Alliance. Lightly edited for clarity.

As part of a home subjected to the brunt of the most intense sun rays, it only makes sense that if you want to make a major difference in keeping your home cooler in the summer, you'd better pay attention to what you put on your roof.

More states are recognizing the value of cool roofs: In Atlanta, an ordinance encouraging the use of lighter color and high-tech roof coatings on materials like metal that are designed to reflect solar was just adopted as a way to make an astounding difference. As Atlanta council member Liliana Bakhtiari, who introduced the proposal put it: "The science behind it shows that if we hit 80% coverage, it would actually reduce the city's overall temperature by 2.5 degrees."

Several states are actively considering or have already adopted cool roof requirements. According to AI, California has the most stringent requirements, and other states like Alabama, Florida, Georgia, Hawaii, and Texas also have cool roof provisions. Hawaii is specifically looking to align its cool roof standards with California's, according to Facilitiesnet.

RELATED: Cool Roof Complexity

Despite the opposition, Baltimore passed a cool roof ordinance in 2023. In some regions like Florida, it's not just city and statewide efforts: local neighborhood residents are lobbying their HOAs to change outdated rules to allow for more efficient, cooler metal roofs, which also offer better longevity and durability benefits.

It's a fact that the U.S. Department of Energy has recognized for a long time: Lighter-colored and cool roofs can reduce the roof temperatures by as much as 50 degrees. Cool roofs cut energy use, curb greenhouse gas emissions and reduce heat-related illnesses and deaths. One recent study found that reflective roofs could have saved the lives of more than 240 people who died in London's 2018 heatwave.

Dark Forces, Debates and the Question of Color

While the adoption of cool roofs is encouraging, recent reports of a "dark force" lobbying effort advocating against cool, lighter-colored roofs have reputedly led to the rollback of more efficient roofing in places like Tennessee and Denver. The group is now targeting national professional energy efficiency codes — the standards that many cities and states use to set building regulations.

RELATED: The Battle Over Cool Roofs Heats Up Following Tennessee Rollbacks

There's no doubt that roof color matters. According to the Guardian article, study after study has confirmed the benefits of light-colored roofs. They save energy, lower air-conditioning bills, and reduce city temperatures. They help prevent heat-related illnesses. And they typically cost no more than dark roofs.

However, color isn't the only thing that makes a difference. So too do materials and installation methods. Members of the Metal Roofing Alliance, a nonprofit trade organization, point to high-tech coatings and paints that can substantially increase efficiency due to their high solar reflectivity. That means with metal, homeowners can choose the darker color roof they may prefer, without sacrificing cool roof capabilities designed to help save energy and stay cooler.

To comprehend how metal roofing with these coatings may increase efficiency, the first step is to understand the sun's energy, which is divided into UV, visible and infrared rays. Infrared, non-visible rays make up the majority, and they produce heat. UV rays (non-visible, cannot be felt, yet can cause wear and tear on building materials) and visible rays account for the rest.

While even basic, unpainted metal roofs will reflect more solar radiation than asphalt roofs, by choosing the proper colors and coatings, low-glare metal roofs reflect mostly non-visible, infrared and UV rays, the kind that produce the most heat and are the most damaging. By re-emitting as much as 85% of solar heat gain to help keep homes cooler, even darker color metal roofs will help lower home temperatures during sizzling summer weather.

"Today's metal roofing styles come in a variety of surface finishes, profiles, textures and substrates and high-performing paint colors," said Renee Ramey, MRA executive director. "Metal roofs look and perform beautifully because they work to reflect and re-emit heat caused by mostly non-visible rays."

It's a fact that home builder and YouTube influencer Matt Risinger highlights at his own home in Austin, Texas, which he built with a dark color metal roof. In a recent video, he pointed to the efficiency of his new roof as one of its major benefits. 

"In the (paint) pigments, we can get a solar reflectivity index number that's very high, and that's not easy to do for asphalt shingles," he said.