Architects and interior designers can be less than the most willing of creative partners. But when equally gifted members of these not-always-allied professions work as a team, the results can be impressive. Witness this Victorian-era cottage in the northern California town of Larkspur. Interior designer Carol Knorpp bought the house with her real estate developer husband, Jon, and hired architect Ken Linsteadt to design a top-to-bottom remodel. “I had worked with Ken before,” says Knorpp, who calls the architect “one of the most creative people I’ve ever come across in the business.” Their seamless collaboration here yielded a residence that is both historically grounded and fresh, personal yet quintessentially Californian.

Knorpp says the house drew her, in part, “because it hadn’t been touched in 50 years.” But its historic designation meant that any exterior alterations would be subject to review board approval. Its configuration—a single-level plan with a semi-finished basement and an unfinished attic—posed additional challenges. Including finished and unfinished areas, the house offered the potential of more than 4,000 square feet of living space, “but it wasn’t very user friendly,” Knorpp says. The main level’s elevation, nearly a full story above grade, was an especially high hurdle, Linsteadt notes. “For a lot of people, that would have been a deal-breaker,” he says.

Because the first order of business was to connect living areas with the outdoors, Linsteadt filled an open corner of the building’s footprint with a large, elevated deck. Given the house’s regulatory constraints, “most of our other moves were internal,” he says. Gutting the lower level yielded space for a two-bedroom children’s suite and a guest quarters. A 1960s-era garage addition became a recreation room with direct access the backyard pool. Three discreet dormers and two new staircases—one for general use and one for secondary egress—opened up a gemlike space at the attic level. “Upstairs, you’re almost in a nest. It’s three stories up, so it gets extraordinary light,” Knorpp says. “We grabbed that for the master suite,” Linsteadt adds, “which left the main floor for living spaces.”

Structural edits and repurposing of existing rooms at the main level updated a choppy Victorian floor plan, locating formal and private functions at the front of the house and casual spaces at the rear. “The heart of the house is now moved to the back,” says Linsteadt, who linked the kitchen, family room, and deck in a carefully composed sequence of living spaces. “One of the bigger decisions we made was disconnecting the family room from the kitchen.” But the resulting plan, with its choice of indoor and outdoor circulation paths, offers a richer experience than would a great-room layout. “It makes this interesting loop,” he says. At its hub—and at the center of family life—is the kitchen’s breakfast bay, whose deceptively oversize windows offer a treetop-level view of Marin County’s iconic Mount Tamalpais.

“One good thing about being up so high is we have wonderful light,” Knorpp says. Her kitchen capitalizes on that resource with abundant glazing and a pale palette of subtly textured materials. The walls and ceilings are tongue-and-groove wood paneling with joints that show random unpainted gaps. The floor is salvaged white oak with a hand-scraped surface; the same material, left rough, covers the range hood. Countertops are Calacatta marble, except for a section of stainless steel at the range recess. The glass-front cabinets draw on the old butler’s pantry model.

Throughout the project, Knorpp and Linsteadt sought sweet-spot solutions that would highlight the house’s historical character while gently nudging it in a more contemporary direction. Presented with an 11-foot ceiling height at the main floor, they raised door openings there by more than a foot. “We replaced the casings with something more modest,” Linsteadt says. “There’s still detail there, but it’s less gingerbready.” The master bedroom’s horizontal paneling, while new, allows a hint of the former attic’s character to ghost through. An eclectic mix of lighting fixtures, sourced from Italy, Spain, Belgium, and the U.S., seasons the project’s enlightened nostalgia with a dash of ironic humor. Such deft moves represent not only the fruits of a successful design partnership, but also a kind of gift to the house itself. “It needed so much,” Knorpp says. “But we didn’t want to take out the history. We didn’t want to take the soul out of the house.”