Attendance topped more than 12,000 at the second annual West Coast Green Conference in San Francisco. Geared primarily for the residential environment, the event was held at the Bill Graham Civic Auditorium.

A highlight of the event was a green modular home erected in front of the auditorium on a patch of grass below the city’s mayor’s office at City Hall. Dubbed the Lotus, the 725-square-foot home was the brainchild of green architect Michelle Kaufmann and boasted solar panels, LED lights, a gray-water system that collects water from sinks and the shower and recirculates it to toilets, an energy-saving “on-demand” water heater and native landscaping.

Architect Sarah Susanka, author of “The Not So Big House,” discussed the benefits of building smaller homes that effectively meet the needs of families at considerably less cost than large homes. Architect Eric Corey Freed of the San Francisco architecture firm organicARCHITECT, which has built close to 100 green buildings nationwide in the past 10 years and author of “Green Building for Dummies,” said building “green” is becoming more viable as the costs of solar panels and water-saving equipment are coming down.

More than 270 vendors displayed products ranging from bioethanol-fueled ventless chimneys to warm flooring, and “green” wall panels.

For information about next year’s conference, visit www.westcoastgreen.com.