Nellie Bristol did her global health policy work from the loft in her Falls Church, Va., home for several years without issue. But when her husband joined her in the home office during the pandemic, things got cramped.

She decamped to her 27-year-old son's former bedroom, which has floor-to-ceiling windows overlooking the backyard. Her son occasionally stays at the house, though, and she didn't want him to feel displaced. She kept his bed, but flipped it against the wall as a daybed, and she purchased a small Hardwood Artisans secretary desk that can close when he's visiting. His books, diplomas and knickknacks are still on the bookshelves, along with his framed photos of sailboats and Wisconsin's Madeline Island, an annual family destination.

The setup has worked well; when her son's home, Bristol shuts the desk and works elsewhere. Kids "like having a familiar place that they can still come back to that still has their stuff," she says. Plus, she likes being around his mementos while she works. "It keeps him close to me."

It's almost a cliché: Kids leave for college, their first job or their first apartment, and their parents or caregivers immediately turn their bedrooms into craft rooms or home gyms. That doesn't have to be the case, though. It's possible to take advantage of the extra space without erasing all signs of the previous occupant.

"You should enjoy as much of your house as possible," says Ann Cariola, an interior designer based outside of Chicago who specializes in helping empty nesters. "Why not make it great for you and your kid so that you're not losing out on those years of enjoyment or functionality in the house?"

Take a beat. Wait about a month after they've moved out before making any big changes to your children's rooms, Cariola says. You don't want them to feel as if you've immediately washed your hands of them. Plus, their new adventure might not be the right move, and they could return to live or stay with you.

The waiting period is also an opportunity to plan how you'll use the space and figure out what you need, says Laura Hodges, an interior designer based in Maryland. Is exercise important? Then maybe you'll want a Murphy bed for more floor space. Will you take Zoom calls there? It might be time to rethink that Baby Yoda poster.

Collaboration is key. Changing a childhood bedroom without consulting your kid could make the process unnecessarily emotional, Hodges says. If you want to paint the walls or change the bedspread, involve your children in choosing colors or patterns, and include them in decisions about mementos and wall art. "It's those small things that make them feel like they're still part of the family, they're still welcome, it's still their space, it's still their sanctuary," Hodges says.

Incorporating your child's preferred aesthetic, such as midcentury modern or boho, can also ensure that the space still feels special to them, Hodges says. And keep a place for them to do the things they like, she says, such as an area for reading or a nook for painting.

Maintain a bedroom feel. Be sure to keep the room's original purpose in mind, and honor the idea that it's still a bedroom, at least part of the time.

"If you walk into the room, and you feel like, 'Oh, this still feels like Mary Jo's bedroom,' I think you've done OK," Cariola says. "If you walk into the room, and you think, 'Oh, this is a craft room,' you've probably taken up too much space."

First and foremost, that means keeping a bed for your child. If you need to maximize space, MA Allen, a Raleigh, N.C.-based designer, recommends getting a daybed with a trundle. And if you're keeping your child's original bed, switching out the bedding is a cost-effective update, Cariola says.

If you're using the room as an office, Hodges recommends purchasing a small folding desk that can be stored or a secretary, like Bristol's, that can close. If you're using your child's desk, take a picture of it, then box everything and store it under the bed. You can consult the photo when the child comes home if you want to stage it the way it was left. You could also turn a child's closet into an office by adding an electrical outlet and a built-in desk, Allen says. Bring in an armoire where they can store clothes when they're home.

For an exercise area, Hodges recommends using small, foldable equipment, such as a rowing machine, that's easy to store. Keep weights on mounted shelves, and use wall bars with resistance bands to save floor space. You can also place rollout bins under the bed to store yoga mats and other small items. And if there's a large walk-in closet, consider adding a pocket door and keeping an exercise bike there, Allen says. Whatever you do, contain all the gym equipment in one area, Hodges says. If weights or bands start drifting across the room, it will no longer feel like a bedroom.

To maximize storage in your child's empty room, don't throw in random pieces of furniture, such as old dressers or chests, Cariola says. Instead, opt for small pieces with storage, such as a bench or trunk, and use rolling bins under beds and dressers.

Declutter together. Reimagining your kid's room is a good time to declutter. "They might be 40, and you go into their room, and it still looks like they could be coming home from soccer practice in high school," Cariola says. "[That] isn't all that useful. [It's] almost like a little shrine to the kids."

Include them in the decluttering process. "It's usually the small sort of tchotchkes and things that are harder to deal with, because many times, those do have somewhat of an emotional response from the child," Hodges says. You don't need to keep all of their trophies, for instance; determine which is the most important and emblematic of their experience. This reduces clutter and also makes that trophy more special.

Hodges recommends looking at each item and determining whether it's functional, beautiful or meaningful. If the answer is no, toss it. If children feel strongly about keeping a lot of items, suggest that they store them where they're living, Cariola says.

Showcase mementos artfully. To incorporate your kid's personality and childhood into the room while also maintaining a sophisticated space, thoughtfully display the items you keep.

Frame photos from a semester abroad or school play posters for display on a wall or bookshelf. And memento boxes can elegantly conceal important childhood memorabilia, as well as any papers or office supplies you may need to store.

Bristol used this approach when rethinking her son's room, maintaining the memories and feel of it without keeping it stuck in the past. "This is the house that we were all in together, and that was a super special time for me," Bristol says. "Being able to carry those memories on is nice."