Like many building product categories, choosing siding for a green-built home is far from cut-and-dried. Among mainstream cladding materials, each product comes with its own set of features and benefits, both from a sustainability perspective and from the attributes of price, installation, appropriateness for climate, and aesthetics. As such, while certain products have emerged as leaders in the green-building industry, no option is perfect. Perhaps this is to be expected, considering we rely on cladding materials to protect homes from the worst Mother Nature can throw at them—and still look good doing it.
“There is no silver bullet,” confirms Vladimir Kochkin, division director at the NAHB Research Center. “And that’s true for almost any product or material.”
Unfortunately, there’s also no category-wide certification program to use as an overall guide, although some manufacturers have obtained third-party verifications for attributes like recycled content and air quality. And most claddings qualify for points under LEED for Homes and the National Green Building Standard.
The first decision for choosing a siding material must come down to what’s suitable for and allowable in your market and location. Following that, here’s a breakdown of how the major types of residential cladding compare on common attributes for green-built homes.
Fiber cement has become a go-to product for many green builders, who appreciate its durability and a look that replicates wood but with lower maintenance. Made with cement, sand, and cellulose fiber, the non-combustible material is resistant to rot and termites, according to ToolBase, carries warranties as long as 50 years, and costs less than wood and stucco.
“What [builders like] first is the durability,” says Prashant Panchal, director of marketing for James Hardie. “Secondly, it’s what the product is made of … None of these elements are toxic.”
One environmental drawback to fiber cement is its high embodied energy during manufacture. Our friends at Environmental Building News also caution that some of the cellulose content may come long distances, so be sure to get documentation on origins.
Fiber-cement planks with recycled content in the form of fly ash are available, such as those from CertainTeed. And though fly ash has recently come under the EPA’s microscope for concerns over hazards in disposal, “beneficial reuse” applications—such as encapsulated in concrete or brick—are exempt.
Because of silica dust, installers should cut outdoors and wear a respirator. Upon tear-down, fiber cement can’t be remanufactured, but it can be ground up for use as fill.
Manufacturers and green experts recommend pre-finishing, which provides an emissions-controlled environment; it also better ensures a quality application and may be required for some warranties.