Kinder, Gentler Backyard

Outside, a large patio with an outdoor fireplace feels like another room. "Living walls" dot the space -- columns of plants that are hydroponically fed with a pump and tubing.

Perhaps the greenest part of the yard is hidden. A retention and filtration basin lies underneath the grass, collecting roof and irrigation runoff and filtering it clean before pumping it into the street. Any runoff is pre-cleaned before going into the ocean. (Los Angeles mandated this in 2012 for all new construction.)