More than 7,500 people attended the fourth Alternative Building Materials & Design Expo hosted by the City of Santa Monica, Calif. in the spring.

Speakers included Panama Bartholomew, advisor to the chairperson of the California Energy Commission; actor and environmental activist Ed Begley, Jr.; Stuart Cooley, energy efficiency engineer for Santa Monica’s Energy & Green Building Program; Owen Dell, landscape architect and contractor specializing in sustainability; David Hertz, AIA, Syndesis founder and longtime green architect; Susan Munves, Santa Monica’s energy and green buildings coordinator; Ellen Strickland, owner and founder of Livingreen retail stores; and John Zinner of Zinner Consultants.

The event featured more than 140 exhibitors and specific topics of presentations included “Greening” of the schools, watershed-friendly and fossil-free landscaping, solar energy/applications, the EPA’s Watersense program, eco-density, and residential project management.