Compressed wheat doors, bamboo countertops and recycled building materials: These and dozens of green-building techniques will be displayed at nearly 20 houses on the Green Home Tour. Sponsored by the Homebuilders Association of Durham, Orange and Chatham counties, it begins May 19 at 9 a.m. at the Carrboro Century Center, 100 N. Greensboro St., followed by a self-guided tour from 10 a.m. to 6 p.m. and May 20 from noon to 6 p.m. Tour books are available at Weaver Street Market and Stock Building Supply in Carrboro, Whole Foods in Chapel Hill and Durham, and at the kickoff event. Some homes will be partially finished, allowing visitors to see otherwise hidden green features, such as spray foam or recycled newsprint insulation. Info: 493-8899 or