When architect Mark Horton was approached to design a home in Healdsburg, California, the client had three requests. First, there should be very little decoration. That was easily accomplished, since Horton is known for a rational, minimalist style. Second, the exterior should require little maintenance. Horton obliged with a galvanized-steel roof, metal siding, and aluminum windows. The third requirement would prove more challenging: The client asked that the house be cozy. “I don’t do cozy,” Horton laughs.

Fortunately, the client happened to be the architect’s 80-year-old mother (and as it happens, a returning client), so garnering a deeper understanding of the request came down to familial duty. Acquiescing, Horton designed a pine wall that runs the length of the 1,850-square-foot house and continues outside under a covered porch. “The feeling of wood—that’s my definition of cozy,” reports the architect’s mother, Yvonne, clearly pleased with the results.

Another warming touch was the addition of a reading nook. Wood-paneled on the inside, stainless steel on the outside, the cantilevered cranny provides a visual break from the simple white-walled interiors and the earth-toned, horizontal exterior. The exterior colors are the home’s only connection to the prevailing architecture of the region—descendants of Tuscany and Provence.

In addition to providing the cozy factor, the wood wall divides the home into public and private domains. A combination living, dining, and cooking area, open and sparse, runs along the south wall. Three bedrooms traverse the north side, where the roof dips down for privacy and warmth. There are few furnishings and nary a lacy doily to be found. “It doesn’t feel like a grandmother’s house,” Yvonne notes.