Jørgensen is also experimenting with strategies lifted from Australian and Spanish builders, who have been designing for wildfires for centuries. Specifically, he hopes to implement a series of protective fire walls, designed to stall an advancing blaze at select intervals from the edge of the property to the house itself. Taken together, the Glen Ellen Retreat and other properties like it should be able to withstand four hours at the center of a blaze. Despite its hardiness, Jørgensen hopes it will never have to endure such a harrowing test. “That’s the stuff that keeps me up at night,” he says.