Why You Should Redecorate Until You Kick the Bucket

“There must be some mistake,” my daughter will say. “Why would a 100-year-old woman order a new sofa?”

The delivery man will consult a clipboard: “Says here she did specify rush delivery.”

You are never too old to freshen up the living room. I will redecorate until I die. So should you. And I’m not saying this simply because of what my family describes as a “diagnosed sofa problem.” I’m saying it because decorating is good for our mental health.

Environmental psychologists, who study how physical space affects our well-being, know that different sofas will make us happy at various points in our lives. The foldout futon that made us feel so grown up in our first apartment gets replaced a few years later by a family-friendly sectional, which in turn gives way to a leather Le Corbusier three-seater that the grandchildren are absolutely not allowed to sit on in their bathing suits.

“People try to paint a picture of themselves in their surroundings,” said Chicago-based psychologist Sally Augustin, author of “Place Advantage: Applied Psychology for Interior Architecture.” “As you move through the stages of life, it’s natural to want to redecorate to reflect those changes.”

When you see a room that looks like a time capsule from an earlier era—whether it’s a kitchen with 1990s granite counter tops or a den with wall-to-wall shag carpeting—it makes you wonder if its owner is stuck in time as well.

We’ve all had older relatives who stopped redecorating. A cautionary tale was my grandparents’ 1980s-era living room, which looked like a movie set from the 1950s: a lumpy, slipcovered couch that never moved an inch in any direction on the cut-pile carpet. A rickety bookshelf weighed down by a collection of hard-bound Reader’s Digests. And a vacuum tube RCA Victor TV, hidden behind the double doors of a mahogany cabinet. No one had turned it on for years; when I was a child, if you wanted to watch television there was a portable set with rabbit ears in the kitchen.

Why didn’t my grandparents redecorate? This wasn’t about money, and besides, it costs nothing to rearrange furniture. In fact, they could have run a classified ad in the newspaper to sell the grand piano no one had played since my Aunt Vicki grew up and moved away. That would have opened up space to move my grandmother’s plant stand, and 400 African violets, to a spot under the other window. It would have been refreshing.

But somewhere along the way my grandparents stopped seeing the possibilities. Or maybe no one told them redecorating could be fun. After all, when we talk about changing the design or décor in older people’s homes, the discussion tends to focus on depressing topics like the need for grab bars in the shower.

At any age people should make decorating changes for aesthetic as well as for practical reasons. Our physical sense of color, smell and touch changes as we get older, which means things that looked and felt good to us when we were younger may not anymore. “The lenses in our eyes yellow as we age, so colors in spaces actually take on a tinge,” Dr. Augustin said. “When you paint the walls white and you’re age 50, the color might look lovely and crisp. But to an 85-year-old, those same walls might look icky.”

The solution? Paint the room a color that looks good to you, said Dr. Augustin. “A small decorating change can be good for your mood or self-esteem.”

My personal decorating hero, and friend, is someone who embodies this philosophy. Doris Fingerhood, a Manhattan-based interior designer who is 90 years old, got her start in the business in the 1940s and hasn’t stopped decorating since. Soon after she arrived in Brooklyn as a World War II refugee, she fixed up her aunt and uncle’s basement (on a budget of about $12) to make a space where she could have her teenage friends over.

These days, most of the business of her firm (which she named Doris LaPorte Associates after marrying her first husband 69 years ago), is to help clients redecorate homes whose interiors she originally designed decades ago.

Her approach to decorating has changed as she and her longtime clients have aged. But her frugality is prized even more by people whom she’s worked with for many decades. “If the design was a thoughtful job and not a quickie, you can keep the bones,” she said. “Sometimes a new piece of furniture or a painting is all a room needs to change the whole look.”

However, she cautioned, be ruthless about updating worn-out rugs, upholstery, and drapes. “Replace anything that looks old or seedy, because your home is a reflection of your own personality,” she said.

Ms. Fingerhood recently freshened up the Park Avenue living room of a client she’s had for more than 40 years. It only required a few tweaks. “She had antiques and good pieces she still liked, so all we did was reupholster the sofa and get a new Oriental rug,” she said. “I think since the rug was so much more beautiful than the old one, it changed the whole room. Also we got new throw pillows, and that made a big difference.”

My own living room could use a few tweaks. “I think my sofa is starting to look worn and seedy,” I confided to her. “But then I always think I need a new sofa.”

“I liked the one you had in your apartment when you lived in Manhattan,” she said, “but if it doesn’t work in California, give it away and get a new one.”

“Give it away?” I asked.

“Easiest thing in the world, you always know someone who needs furniture,” she said. “Send me some photographs of the room and we’ll work from there.”

—Ms. Slatalla is an editor for remodelista.com which, like The Wall Street Journal, is owned by News Corp.