Not only is metal roofing great for your home, it's great for the environment. The recycled content of the steel in a metal roof is about 28% from production to installation to reuse - far superior to asphalt.
According to the National Association of Homebuilders Research Center, 20 billion pounds of asphalt shingles are dumped into U.S. landfills every year. If you loaded those shingles into tractor trailers, then lined them up end-to-end, they would make a line from New York City to Los Angeles, back to New York City again, then on to Chicago.
That's a lot of wasted asphalt. But because a metal roof can often be installed over your current roof, without tearing off what's already there, metal roofing helps to reduce this excessive shingle waste