"Life brings you things that don't necessarily fit into your decorating scheme," says Rita Konig. While the English designer may be thinking about tennis rackets that clash with mudroom walls and family heirlooms too kooky for the mantel, she's also giving voice to a deeper truth: Leave room in your plans for serendipity.\n\tAdvertisement - Continue Reading Below\n\t\n\nThe kitchen table and chairs are by Howe, the bench is from Past Perfect, and the wallpaper is by Pierre Frey.To make the most of this wisdom, however, you must be able to recognize which of life's unexpected gifts are worth holding on to. Mark and Blythe Harris almost missed the signs when they were first shown a quirky property in Mill Valley, California. It had been a YWCA summer camp in the 1880s and, by the mid-2000s, was "a deeply dysfunctional situation for a family," says Mark. Sited at the top of a steep slope, the primary building was supported on stilts; outdoor staircases connected it to a handful of small buildings below. "We walked in and walked out," says Mark. "We just didn't have the appetite to take it on."\n\tAdvertisement - Continue Reading Below\n\t\n\nA painting by Sam McEwen hangs above the bed in the master bedroom, the walls are upholstered in a fabric by Raol Textiles, Vaughan lamp bases are topped with shades by Guinevere, and the rug is by Luke Irwin. Two nights later, Mark woke with a start. "Blythe found me pacing at the end of the bed with a crazed look in my eye," he recalls. "I said, 'We've got to buy that house.'"\n\tAdvertisement - Continue Reading Below\n\t\n\nBlythe and Mark Harris, with their children, Olive and Freddie, at their Mill Valley, California, home, which was renovated by architect Gil Schafer and interior designer Rita Konig.It was a bold leap. At the time, they were on holiday in California, where Blythe grew up. Home for the Harrises was New York City, where they both had jobs they loved\u2014Mark as founding partner of the Axiom law firm, and Blythe as creative partner in Stella & Dot, a start-up selling accessories (including her own jewelry designs) via social media\u2014and where they were happily ensconced in a comfortable Greenwich Village apartment. Not to mention that they already had one small child, with another on the way.The handmade windows are fitted with mouth blown-glass panes, the cedar-shingled exterior is painted in Black, with trim in China white, both by Benjamin Moore, and the garden is planted with Royal Sunset climbing roses. But the Mill Valley property spoke to them. "Mark and I grew up going to rustic camps," says Blythe, "me in the Adirondacks, and he at his grandfather's fishing camp in northern Ontario." And since both had jobs that allowed them to live wherever they wanted, they set about transforming the eccentric property into a family home.\n\tAdvertisement - Continue Reading Below\n\t\n\nStools by Julian Chichester line the vintage bar, which was bought locally at the Tyler Florence Shop, the sink fittings are by Lefroy Brooks, and the cane chair, found at the Santa Monica flea market, has cushions of Josef Frank linen by Svensket Tenn; the checkerboard floor is painted in Farrow & Ball's Off-Black. To pull it off, they tracked down Konig after seeing her work in a shelter magazine. At an early meeting, the couple told her they especially loved the way she hung pictures. "I thought, Oh dear," says Konig, because the arrangements they admired had been composed of art her clients had acquired over time. "The Harrises were starting from scratch. They lived in a rental and didn't own much."The master bath tub is by Waterworks, the sink and all the fittings are by Lefroy Brooks, and the painting is by Hugo Guinness; the walls are painted in Benjamin Moore's White Dove, the floor in Farrow & Ball's All White. Fortunately, there was no rush to decorate. It would take three years to convert the place into a livable house. To oversee that process, the couple hired Gil Schafer, an architect better known for patrician estates than ramshackle summer camps. "We chose him because of the beauty of his work, his attention to detail, and his respect for history," says Mark. "He's so humble. He didn't impose on the house. He could roll with its imperfections."\n\tAdvertisement - Continue Reading Below\n\t\n\nIn the family room, the George Sher lock sofa is upholstered in a Raoul Textiles linen, the ottoman, covered in a de Le Cuona corduroy, is by Howe, the armchairs are from Dean Antiques, the stool is a Paris flea-market find, and the antique bench is from Ruby Beets; works by Sam McEwen and Hugo Guinness, among others, hang above the fireplace, the walls are painted in Emery & Cie's C'est Un Gar\u00e7on, the cane shades are from Joss Graham, and the rug is by Beauvais Carpets.He had plenty to roll with. "The family needed more space, but the footprint couldn't get bigger," says Schafer. "The only way to increase its size was to insert rooms underneath"\u2014to stretch the main house vertically, which they did by excavating the slope and raising some ceilings. "We had to take the house completely apart," says Schafer. "Everything you see that looks old is actually new."Antique chairs from Mudpie surround a vintage French dining table from Ruby Beets, the table lamps are from John Derian, the chandelier is from Big Daddy's Antiques, and the walls are painted in Emery & Cie's Vermoulu 6. \n\tAdvertisement - Continue Reading Below\n\t\n\n"We spent a lot of time imagining what would go on in the house," says Konig, who quickly began acquiring things that would lend character and warmth to its rooms. "The Harrises believe in details and discoveries, and they trusted me. So I'd buy something odd, like a ship in a bottle or a stuffed seagull\u2014I mean, who bothers to stuff a seagull?\u2014and they'd get excited about it. Other clients might say, 'That's a detail; we can deal with it later.' But they understood that sometimes, little things matter most." Details are what allow you to create the story that gives life to a house.The living room's custom-made daybed by Charles H. Beckley has a cushion covered in a Twill Textiles stripe, the 19th-century armchair, in a Holland & Sherry tweed, is from Alexander von Westenholz, and the floor is painted in Farrow & Ball's Pavilion Gray. Meanwhile, Mark got involved with every aspect of the design. He oversaw the installation of the salvaged floorboards, to ensure that the gaps between them were irregular\u2014"the way they would have evolved over time," he says. He also tracked down vintage butcher block and handblown windowpanes. \n\tAdvertisement - Continue Reading Below\n\t\n\nThe kitchen features custom-made cabinetry, a range by Wolf, and a Rohl sink with fittings by Lefroy Brooks; the blue pendant light was found in London. "I'm used to making the creative decisions," says Blythe. "Suddenly, my lawyer husband is having all these ideas. I didn't know he had it in him." Yet what could have turned into a clash of wills became a collaborative triumph. "We put our styles together, and our family style emerged," she says.The terrace off the master bedroom holds wicker seating, painted in Farrow & Ball's Off-Black, from Beall & Bell, the pillows are covered in a fabric by Jennifer Shorto, the folding chairs and painting were found at a Paris flea market, and the antique chandelier is from Ruby Beets.Creating a space where such unexpected gifts can blossom may be exactly what the right home can do for a family. "A house can be a vessel for change," says Mark. "To envision how it will shape your life and then to live the way you'd hoped\u2014it's kind of profound.To save this story, pin it for later. For more amazing spaces, follow ELLE DECOR on Pinterest.