There were already quite a few “guests” in the yard, technically speaking: The house shared space on its 7,500-square-foot lot with planting beds, a massive pond and a rear deck. Karen and Mina decided to add a pull-through driveway on the side of the new barn so the yard would still be accessible from the other end of the property.

Demolition for the bonus barn was minimal — Karen planned to place it in the mostly-empty spot at the back of her lot — and immensely satisfying, since both she and Tad got to break up the existing concrete pad with a Bobcat. “I really like operating a jackhammer,” Karen said, “and if we put that on steroids — if we put it on a Bobcat — I’m gonna love it even more!”

Mina was skeptical before construction began: “I don’t even know how you have room for a guest house back here, to be honest,” she confessed to her mom. Karen was undeterred, and she packed everything into a 35-by-36 footprint. “It’s gon’ be snug, but it fits!” Mina conceded.

City officials put the squeeze on Karen’s original plans by denying her permission to build a second interior story that carried all the way to her property line. Ever the optimist, Karen reworked her plans to include a massive upper deck (that just happens to be a perfect place for grandbabies to play). She chose pale grey-blue exterior paint with white trim to match the main house’s color scheme.

The barn’s signature feature — soaring, exposed trusses for the gambrel roof — is the result of a yoga-class daydream (seriously). “I was in a barn doing yoga, looking up [at the ceiling], thinking, This is what I want mine to look like! ” Karen said. When she realized she could double down on the rustic look by paneling the ceiling with reclaimed barn wood, she nearly levitated with happiness.

Set against darker, unpainted panels, the ribs in Karen’s gorgeous new ceiling have the delicate look of crocheted lace.

Karen paired a bold Expressionist painting with pale quartz countertops and minimal shelves in the barn’s diminutive kitchen. As she kept the walls above those countertops pale and open, the space still manages to feel wide open — and the eye travels straight up to the architectural details above.

Karen rescued this sink from demolition in a house she and Mina rehabbed. Reglazed and fitted with new hardware, it just happens to be the perfect fit for her new guest kitchen.

Mina squealed at the scaled-down, “cutest little baby appliances” Karen sourced for the prep area. These features are just enough to whip up an intimate meal — and they don’t steal valuable floor space from the living and dining rooms.

While guests will likely join Karen and Roger for most meals at the main house, she wanted to give them a gathering space of their own, as well. Paired with a distressed area rug, the delicate floral fabric on her four high-backed chairs does indeed say “Parisian reclaimed barn,” as Mina called her mom’s vision.

Accessible by a ladder from the living room, this just-for-kids loft space is an HQ for the grandbabies. (Karen’s not-so-secret dream in building the barn was to encourage her San-Francisco-based son, C.R., to bring his wife and two sons to visit more often. Mina was on board: “They’re the cutest grandbabies ever so they have to come all the time!”)

Karen used panels of printed wallpaper (pasted in place, then protected with a layer of polyurethane) to create a map of the world in the upstairs bonus space. She’s A-OK with the fact that its kraft-paper borders are a little less than even: “If I’m doing it, it’s not an exact science,” she said.

The backyard barn is full of one-of-a-kind touches, but Karen kept things simple (and sturdy) on the floor: She chose “inoffensive and neutral” engineered vinyl plank, which mimics the look of hardwood and will last forever.

Karen didn’t have an official reason to save the intricate metal grates she’d been plucking from renovation projects, but her hunch that they would come in handy one day paid off big time. She asked her builder, Dallas, to frame them out as an installation along the second-story loft space: “It would be like a little crazy-quilt railing with all those grids in it!”

This cozy living room can accommodate even more overnight guests, since Karen outfitted it with an extra-long sleeper sofa. We predict it’ll play host to additional artwork, as well: “I have a million ideas for what to put on the walls,” she said. (“Shocking, shocking ,” Mina replied.)

The open-concept dining area, kitchen and living room flow into one another and feel like distinct spaces, as Karen punctuated each one with focal points of its own. Art, architecture and accents all have the chance to shine, since she painted the walls white and chose a usefully-neutral “greige” for the rooms’ trim.

A visit to a friend’s woodworking shop inspired Karen to offset the barn’s reclaimed-wood ceiling with — what else? — a pair of custom sliding doors between the living area and the bedroom.

Karen’s daughter-in-law loved the space she created at the rear of the new barn: “It’s like a little sanctuary back here!” she exclaimed. From here on out, visiting family will curl up in comfort at the end of the day.

A dark, elegant dresser matches both the headboard and a second dresser in the living area. Behind another sliding door, the bathroom is a showstopper: Karen equipped it with a 60-inch clawfoot tub she’d saved from another project and refinished. (Mina: “I’m so glad you’re finally using one of the things you hoarded!”) Get ready for a lot of visitors, Karen.

The first-floor garage and utility space aren’t as dramatic as the second-floor guest suite, but they’re every bit as useful: Karen added storage and a slop sink for her heavy-duty projects as well as parking for Roger’s motorcycle and the electrical vehicle she plans to buy (and will service with her own charging station on the other side of a first-floor bathroom).