As public interest in eco-friendly houses grows, so too does demand for green building products. Made with ingredients that are less harsh than conventional sources, these materials are easier to live with and, presumably, healthier for the environment. Presumably. And that's the problem. Defining what's truly green and what's merely green-tinged isn't easy. Is the priority for your spec energy conservation, sustainable origins, or health concerns? Should it also be recyclable and easy to maintain? Or is it simply enough that it lasts a good long time and will be preserved and cherished by others? Well now there's another shade of green on the rise for your consideration: bio-based building products.

natural selections Unlike products that use so-called safer man-made solvents, bio-based materials derive primarily from natural raw ingredients, making them as benign as their origins. Once a small subcategory, bio-products now cover a gamut of building applications, among them panels made from agricultural waste fiber, soybean foam insulation, and paints and adhesives almost safe enough to swallow. Forward-thinking architects, builders, and even consumers have known about some of these products for years but now have a more mature industry to plumb.

Architect Theresa K. Phelan uses nature-based products in as many projects as she can. The president of Issaquah, Wash.–based Living Shelter Design Architects enjoys the products' intrinsically different look and believes they're clearly better for the environment and much healthier for her clients. Among her favorites are earthen-based plasters and water-borne finishes.

Bio-based products also promise performance advantages over conventional specs. “These types of products often have characteristics that are better [than traditional products],” says architect Nancy Malone, a senior associate and product researcher at Siegel & Strain in Emeryville, Calif. Malone says, for example, that wheat-based paneling is “hard and durable and has a unique aesthetic that other paneling does not have.”

Wane Fuday, CEO of Lake Oswego, Ore.–based Humabuilt, a healthy building systems supplier, agrees. His company offers what he calls the first affordable interior door made of wood veneers blessed by the Forest Stewardship Council, engineered cores of wheat (a rapidly renewable fiber), and water-based adhesives. “At least 85 percent of our doors are made with a product that would have been thrown away,” he says. He also claims they're much denser than other products on the market, resulting in greater sound insulation and warp resistance.

Another agriculture-based building material is Kirei by San Diego–based Kirei USA. This eco-friendly building panel is made of 100 percent sorghum stalks, a drought-tolerant and water-conserving grain, and formaldehyde-free adhesives. What's more, the company says, the product removes stalks from their usual fate as landfill waste, another eco-good deed. The panel is well suited to architectural applications such as cabinetry and countertops. Similarly, Portland, Ore.–based Isobord Enterprises fabricates particle board from straw.

Sprayed polyurethane foam, a petroleum-based product, is a popular insulation material among architects who seek an extremely tight house. But green-minded designers can spec a natural alternative in BioBase 501, a spray-in-place insulation made from soybean oil. Manufactured by BioBased Systems in Rogers, Ark., the product emits no VOCs or chlorofluorocarbons, and contains no formaldehyde. “It behaves much like petroleum-based plastic foam, without any of the environmental side effects,” the company says.