For home builders, the LEED for Homes Projects expands the New Construction Rating System for commercial building certification to include homes. A pilot LEED for Homes program began in November 2004. Since then 10,000 homes across the country have participated in the program, and 46 states now have third-party certifying bodies. Certification, which includes standards for resource conservation as well as indoor air quality, ensures that single- and multi-family homes will have been third-party inspected and certified to perform better than conventional homes.

The USGBC is also sponsoring the LEED for Homes Initiative for Affordable Housing. "Green homes are tremendously beneficial to human health," says Katz, "and low-income people are disproportionately affected by asthma and other health-related issues." Cheap building materials, like PVC and formaldehyde-heavy particleboard, often trigger these health problems.

Behforouz isn't pursuing LEED certification with her client in Indianapolis because the home was started before the program was developed. Still, "I think it will be the norm for homebuyers to demand a home that has been certified under a green-building/energy-efficiency program," says Laura Uhde, the director of residential green building services for the non-profit Southface, dedicated to sustainable energy and environmental technologies.

"So many new green products are coming out," says Behforouz. "Ten years ago it was really tough to find the products, but now it's very easy." To get you started, consider the latest green building materials:

FLOORING

Eco Timber: FSC-certified and reclaimed wood flooring; the company's HealthyBond adhesive is virtually VOC-free (7 grams per liter), and many of the products are formaldehyde-free. Pre-finished floors are UV cured at the factory to further decrease VOCs (www.ecotimber.com, 510-809-8200).

Duro Design: bamboo, cork, oak and eucalyptus flooring with low-VOC finishes (www.duro-design.com, 888-528-8518)

Shaw Industries: modular carpet featuring PVC-free, recycled-fiber EcoWorx backing (www.shawfloors.com, 800-441-7429)

Eco-Friendly Flooring: funky 100-percent recycled aluminum, brass or glass tiles for floors, walls and ceilings (www.ecofriendlyflooring.com, 866-250-3273)

Sisalcarpet.com: natural-fiber rugs and carpets made from seagrass, hemp, jute, coir (from coconut husks), wool blends and even paper (www.sisalcarpet.com, 877-757-4725)

Dodge-Regupol: ECOsurfaces recycled rubber flooring line (www.regupol.com, 866-883-7780)