My friend Carla has a theory about long marriages. She claims that the relative success of a marriage is directly proportional to the square footage of the house in which the couple live.

She maintains that her marriage to husband Don has lasted more than 30 years only because their house is big enough to accommodate separate spaces for portions of their days together. “You stay on your side and I’ll stay on mine,” she tells him, “and I’ll meet you in the kitchen for dinner at 7 o’clock.”

Those of us who have known this couple many years know Carla possesses a rather wry and deadpan sense of humor. On their 30th anniversary, Don proposed a dinner toast to her, saying, “It doesn’t seem possible that 30 years could have passed so quickly.” She responded dryly, “Well, honey, it doesn’t seem that long because you’ve been on the phone for most of that time.”

Anyone who has been involved in a long marriage probably understands Carla’s sentiments and knows that it takes certain accommodations to keep a healthy relationship alive. Recent statistics indicate that American divorce rates are near an all-time high. Surveys reveal that young couples are now waiting longer to marry, with many choosing to live together as an alternative to traditional marriage.

The plot thickens

For those of us who have been less successful in marriage, we occasionally stand in awe of couples who have been able to solve what appears to be a puzzle as difficult and complex as “The Riddle of the Sphinx.”

In younger years, many of us believed we’d be spending endless days blissfully sharing our lives with our partners. We pictured scenes of walking hand in hand and never wanting to be separated from each other. Our naivete was best described in the words of writer Carolyn See: “That was before life’s plot had begun to thicken.”

My parents never had the luxury of utilizing Carla’s “More Square Footage = Better Marriage” theory because they owned a small post-World War II cottage and space was always at a premium there. However, they silently staked out their individual domains during their long marriage. My dad worked outside in his garden, while my mother lived and worked inside the house during the daylight hours. Meals brought them together in the dining room, and then each slipped quietly back into his or her own comfortable routine.

Having the benefit of spacious accommodations is best exemplified by a successful Houston couple I know who live in a 10,000-square-foot home and have seemingly enjoyed a healthy and enduring marriage. I imagined they wander the cavernous space for days and simply cannot find each other in a house that size, which only reinforces the old adage about absence making the heart grow fonder.

The happy duplex

I may have solved the “Sphinx” mystery with my own living arrangement. About a decade ago, I bought an old Spanish bungalow duplex which has a wall dividing the house down the middle. I rented the other side out to a nice woman who has since become a close friend. We share the laundry facilities and occasionally enjoy meals together while catching up on one another’s lives. Since she lives on her side of the house, I’m never concerned whether she picks up after herself or stays in the bathroom too long. We’ve never once had a fight. In fact, I can’t think of a single annoying habit she has ever exhibited. I believe we may have accidentally discovered the perfect “marriage.”

At the dinner table that evening during my friends’ 30th-anniversary celebration, Carla informed Don that he had dripped barbecue sauce on his chin. As he grabbed his napkin, she drolly offered, “You’ll have to pardon my husband’s table manners because he normally eats over the sink.”

Carla said she knew there was still magic in their relationship when Don presented her with a garbage disposal the previous year on their 29th anniversary. “And just when I thought he had found the perfect romantic gift, he topped it this year by giving me a trash compactor. Now I’ll be able to think of him each time I take out the garbage. That man is such a charmer.”

Who says modern marriage is in trouble? Romance is still very much alive and well. At least it is in my friends’ home, which coincidentally just happens to have the necessary amount of square footage.

Bob Vickrey is a native Texan and a member of the Board of Contributors for the Waco Tribune-Herald. He lives in Pacific Palisades, Calif.