Wood

Many consider wood the ultimate sustainable material and renewable resource, and therefore one of the greenest cladding choices. Its long history as an exterior finish has established a built-in appeal to many buyers that can boost resale values.

Western red cedar, which comes to mind first for many, is naturally durable and, with proper maintenance, a long-lasting option. According to Paul Mackie, western field manager for the Western Red Cedar Lumber Association (WRCLA), cedar also is lightweight in transport.

In separate third-party life-cycle assessments (LCAs) conducted by the WRCLA and the Vinyl Siding Institute, cedar finished ahead of all cladding in both studies—fiber cement, vinyl, and brick or brick and stucco. In the WRCLA study, cedar received top marks in five of the seven criteria; the two categories in which it didn’t perform as well—smog and eutrophication—the WRCLA attributes to paint, noting that higher-quality paints and stains or new waterborne products are one way to help offset this.

Cedar siding is resistant to moisture and insects and doesn’t have to be treated; left unstained, it will develop a patina and will need to be cleaned with a mild oxygen bleach solution. To retain its original color, staining and maintenance will be required. Prefinished products are often available.

Still, with cost premiums and annual limits on availability, cedar isn’t always a feasible choice. What’s more, supplying materials outside the Pacific Northwest means shipping long distances.

Among the other wood options are redwood, cypress, Eastern white cedar, Douglas fir, and pine. For the most sustainable selections, look for local sources and products with third-party certifications such as FSC, SFI, and CSA.

Phil Kaplan, AIA, principal at Kaplan Thompson Architects in Portland, Maine, uses locally sourced Eastern white cedar or white pine for some of his projects (along with fiber cement and metal). The cedar does not require treatment (although it can be stained or painted); without treatment, the color starts uneven, but evens out over time, Kaplan says. Pine is a less expensive option, but does require treatment.

Builder Michael Chandler has found tulip poplar an affordable, extremely local option in his North Carolina market. He also has utilized BarkHouse siding, in which the bark of trees bound for furniture manufacturing is stripped and crafted into shingles.

Resource-efficient engineered products also are available; be sure to research the chemical content of binders, treatments, and finishes.