Massey Burke, left, and Trilby DuPont talk in front of the cob wall building of DuPont’s design on Burke’s property in El Sobrante on March 11,
Massey Burke, left, and Trilby DuPont talk in front of the cob wall building of DuPont's design on Burke's property in El Sobrante on March 11, 2014. A group in Berkeley is working to revive the ancient cob wall building technique, claiming it to be more sustainable and environmentally friendly than conventional methods. (Kristopher Skinner/Bay Area News Group) ( Kristopher Skinner )