Jay Shafer sweats the small stuff. Hopping into a waist-high metal bathtub smaller than a shower stall, Shafer swung a faucet over his head to demonstrate how one bathes in the combination tub/shower/sink. Gesturing at the composting toilet a foot away, he added: This bathroom is the part of this house I'm proudest of. It was inspired by the Japanese model of being very compact and very efficient. The whole room is 11 square feet, smaller than a standard closet." Thinking small, targeting simplicity and paying meticulous attention to detail exemplify Shafer's craft: designing tiny houses. The Sonoma County resident is considered a father of the tiny house movement, a burgeoning trend to live more efficiently in less space. "Jay articulated and popularized a philosophy of live small, live debt free, and have more time and freedom to pursue your life's passions," said Ryan Mitchell, editor of TheTinyLife.com, a website dedicated to living in small-scale structures. "He backed it up with some really attractive designs." From a 119-square-foot house in Graton, Shafer, 49, writes books about small dwellings; whips up blueprints for Craftsman-style houses ranging from 98 to 288 square feet; plans weekend workshops for DIYers; and sketches out his latest brainstorm: an entire village with dozens of tiny dwellings, each less than 400 square feet, plus a larger common house and other shared amenities, to be erected in Sonoma County. In fact, the county is a hotbed of the small-house movement, with an annual exhibit at the Sonoma County Fair, several small-house companies and at least 100 tiny dwellings.