Sarah Darnton is the first to admit she’s a hoarder. Not the type who deserves her own TV show, but a sharp-eyed collector who can’t bring herself to throw anything out. That’s how she and her husband, real estate investor Chris Fiegen, came to feel cramped in the Evanston manse they’ve been living in for nearly a decade. Even from the start, it hadn’t been a perfect match for Darnton, whose casual tastes clashed with the warren-like 1937 Tudor. When the couple, who met at the University of Michigan, first walked into the 9,000-square-footer after years of searching, Fiegen “got that feeling when you know a home is right,” says Darnton. “But honestly, I didn’t. I was just snookered by the owner’s elegant style.”

As the years rolled by, Darnton filled the multilevel home with three children and the toys and gear that go with them, along with her endless acquisitions: Turkish rugs, vintage china, glassware, art books, paintings purchased in Santa Fe (where her parents live), and furnishings from every era. “Nothing fit right. All the furniture made the home look like a dollhouse. It was dark and stuffy and not fun,” she recalls as she picks up Nerf bullets that litter the stairwell. “Eventually, it dawned on me that we were piecemealing this place together, and it didn’t feel like my home at all.” Darnton had been on several North Shore house tours and knew she liked the work of interior designer Julie Fleps. “So I wrote her an email explaining my situation, and she agreed to help.” The couple’s vision? To reorganize the Tudor as efficiently as possible, transforming the stuffed-to-the-gills house into a fresh, open, sophisticated space.

When Fleps first saw the house last spring, she marveled at its “festival of wood”: wood paneling, wood floors, wood doorways, wood built-ins, wood everywhere in every tone. Her plan? Strip it all down to its natural stain and lighten the place up. A test section revealed gorgeous oak panels; Darnton and Fiegen were thrilled to discover such beautiful bones. So the family of five—along with their two cats, two dogs, and two chinchillas—moved out for four months and returned to a sun-drenched home that barely resembled its former self.

Now when Fiegen comes back from a business trip, he enters a mudroom organized with baskets and cabinets leading to a whitewashed kitchen, its enormous granite island often hosting kids doing homework. The adjacent formal dining room is spare, with Darnton’s collectibles tucked into a Piet Boon cabinet. Scandi-style Artifort chairs surround a glass and white-painted aluminum table. In the living room, the Tudor’s original molding and paneling are washed in a soothing white, adorned with David Loren Bass paintings and a gnarled Thai vine. In the family room are shelves lined with Darnton’s pottery and a sofa big enough for the whole family. Just beyond that is a garden room, where Darnton likes to hide out and read a book. “No one looks for me in here,” she says with a smile.

What Darnton and Fiegen didn’t purchase through 1stdibs, Nickey Kehoe, or Assemblage, they had custom-made by local woodworker Erik Gustafson or found in Darnton’s stockpile. “The sink was in the basement. The rugs were all over. We mostly just shopped the house,” Darnton says. Fleps used the old wine cellar to store seasonal and out-of-rotation goodies—pottery, glassware, pinecones, Christmas ornaments—that her client couldn’t part with. She calls it Sarah’s prop shop.

There’s plenty of space for whimsy in the seven-bedroom, 10-bath home, especially upstairs. Strategically placed sofas, chairs, and rugs pop in pink, teal, green, and orange. One powder room is lined with Boråstapeter wallpaper of pigs in sweaters, and the chandelier hanging above the stairwell is a ­powder-coated steel mise en scène of water lilies. The cheery children’s rooms appear very lived in, and the playroom features a mirrored wall for the kids to doodle on and an enormous table salvaged from the renovation.

The family officially moved back in at the start of the school year, but it wasn’t until Thanksgiving that they fully finished their home’s transformation. “It was like seeing our old home with new eyes,” recalls Darnton. “It was fresh and bright. It literally sparkled.”

Finally, she says, “our home is a happy place to come back to.”