Any new framing lumber was kiln-dried and kept covered during storage to avoid moisture and mold buildup. “Most lumber has been sitting in the lumberyard for weeks and, in many cases, will have black fungus growing on it,” King says. “By the time you add insulation, you’ve trapped water in the walls.” Wall cavities were insulated with cotton denim batts; blown-in cellulose insulates some of the ceilings. The house’s mechanical system is robust. King’s crew retrofitted the house with a radiant heat system fed by a 96%-efficient Munchkin boiler. Rather than rip up the floors, “we screwed aluminum transfer plates to the bottom of the floor sheathing from the underside,” King explains, “and pulled the tubes up through the existing joists into the transfer plates.”

The hot-water delivery itself was designed for maximum efficiency. The main plumbing trunk passes through the center of the house, minimizing the length of secondary pipe runs and, thereby, heat loss. And each pipe is insulated to its point of use—an upgrade from California’s Title 24 Energy Code, which requires only 5 feet of insulated pipe beyond the water heater.

One of the owners’ requests for this project was to avoid drywall, so King finished the 3,600-square-foot interior with a combination of plaster and wood walls, some of it salvaged from a third-story redwood deck.

Other high-end finishes in the 15-month project include stonework that figures prominently in the baths. A child’s bathroom is marble-tiled top to bottom, and the master bath contains slab marble.