When Maricé Chael added on to her historic 1920s cottage in Miami, she wanted to stay true to the look and feel of the neighborhood. Because her home’s original 80-year-old stucco had held up so well, it seemed logical to use the same material on the addition. As Maricé discovered, stucco is durable and requires little maintenance, but its primary ingredient, Portland cement, requires huge amounts of energy to produce.

The truth is, no particular type of siding is a clear environmental winner. The old standbys offer few environmental benefits: Vinyl is persistent in the environment and poses hazards to factory workers, and aluminum is nonrenewable, albeit recyclable. "Ultimately it comes down to picking something that’s going to last a long time, that’s low-maintenance, and that’s going to be a part of a well-insulated and well-drained wall system," says Nadav Malin, vice president of BuildingGreen and editor of Environmental Building News.

Proper installation is key to all siding systems. "It’s important not to think of siding as an isolated product, but as part of a whole system of weather protection," Malin adds. He advocates leaving an air gap behind siding, which allows water to drain away from—instead of remaining trapped within—the walls. "You’re going to be ahead in terms of protecting the house from moisture damage and water problems," he says.

Which wood would you choose? 

The iconic American house is sided with clapboard—also called bevel siding, lap siding or weather-board—typically made from tough, insect-repellant cedar, pine, spruce, redwood, cypress or Douglas fir. Ask for lumber that’s certified by the Forest Stewardship Council (FSC). "That’s kind of the gold standard," Malin says.

Reclaimed timbers salvaged from old buildings, river bottoms or downed trees can be superior to new because older logs likely came from slower-growing trees with a denser grain. You may pay a premium for them, though.

The drawback of wood siding is maintenance. It must be painted or stained every few years. Otherwise, it can rot or suffer insect damage.