Martha McCarthy, who has been practising family law for more than 15 years, says the worst part of her job is that moment when she must tell a client that no matter what -- no matter how intolerable the situation -- they have to remain in the house with the spouse they are determined to divorce.

She does it, she says, because the precedent in modern Canadian divorce law compels her to, and because her client would otherwise be woefully disadvantaged in the legal proceedings if they were first to yield the marital battleground.

"But I hate giving that advice," says the Toronto lawyer. "Every time I give it, I hate hearing myself say it. I think it's awful."

Where once most couples sought separate accommodation shortly after deciding the marriage was over, today's divorcing couples often remain together in the same home for a period of time, sometimes for extended periods.

Ms. McCarthy, who runs a busy family law practice in Toronto, says she has had divorcing clients -- even not entirely amicable ones -- who remain in the same house for as long as three years.

It is a trend driven by legal precedents that tend to punish those who move out, particularly in the matters of custody and access to children, and also occasionally by a reluctance to settle for lesser-quality accommodation.

In practical terms, however, it can be an excruciating day-to-day existence for couples barely on speaking terms to play house at a time when their animosity toward each other is often white-hot.

"In the beginning, I wanted to scream all the time," said Louise, who launched her own blog, Tag You're It, to vent about what it was like to keep living with her husband after finding out he had cheated.

"Kick him out? Maybe that worked 20 years ago. Lawyers do not advise their clients to leave the matrimonial home, even though it may be the best thing to do emotionally.?

"Initially, he agreed to move out. But after he went to his lawyer, everything changed," she said in an interview.

"His lawyer told him to stay put, and he did."

More than eight months later, the pair are still in the same suburban house in which they raised their three children during 10 years of marriage. Together, they have prepared the house for sale, completed renovations, painted and primped up the family home.

"But the anger is enough to make you do and say things you'd rather not," said Louise, not the real name of the 44-year-old professional who is as disarmingly candid as she is attractive.

"Living together is pretty volatile.? It's hard to figure out the issues when every day you wake up and come face to face with pain and anger."

Ms. McCarthy says she has had clients who have squabbled about sharing groceries with each other and who refuse to do each other's laundry.

She has even heard of one couple who used duct tape to draw a dividing line through a house -- but still they reside under one roof until some sort of agreement, though tentative, is worked out.

"Status quo matters," Ms. McCarthy said, trying to explain the pragmatic working of divorce law. If a couple decides the best thing is for one party to temporarily vacate the house, leaving the kids behind, then that will become the acceptable norm for the courts, she said.

"It is extremely prejudicial to the person moving out."

So how does she sell her clients on a proposition that for many of them is utterly unpalatable? This is what she tells them: "You cannot agree to anything on a temporary basis that you wouldn't be willing to live with in the long term."

And so, she explains, for anyone who seeks some sort of serious child custody arrangement or desires sole custody of children, relinquishing any bit of ground in the household arrangement -- even temporarily -- is simply out of the question.

Grant Gold, another family law lawyer who has a surprising number of clients who continue to live together for increasingly long periods of time, says he tells those who say they cannot stand living in the matrimonial home that "what you lose by getting out is the ability to get back in in a hurry.? I don't want anybody leaving until there are arrangements in place for kids, for money; if you're the dad, I don't want you leaving until we have visitation nailed down."

That was certainly the experience for one lawyer, whose wife told him she was tired of the big house, his demanding job, and everything else about their upscale lifestyle when she said she wanted a divorce.

(He didn't discover until months later that she had hooked up with the basement renovator.)

"I felt sick being around her after a while. I was told not to move out until I had something in writing," said the man, who does not want to be identified.

His three children were teenagers when his marriage broke up, and he wanted to ensure he had equal access to them.

He ended up staying in the same house for four mostly unbearable months before getting an equitable interim agreement on custody.

Ms. McCarthy, the family law expert, says she has had several cases where one partner's refusal to move out, and the intractability and generally untenable situation, is what ends up driving an otherwise reluctant partner into an agreement.

She says the only alternative is for couples to employ what is known as a "nesting" arrangement, in which the children remain the constant in the house with a changing case of parental characters in charge of the home.

But that, too, can be fraught with tension over such things as sharing closet or fridge space, and even, on opposite nights, a bed.

It is all a far cry from the kinds of post-marital arrangements described in a new book by Toronto journalist Cate Cochran, Reconcilable Differences: Marriages End. Families Don't.

In it, Ms. Cochran-- whose break-up with her husband was so amicable that they bought a house together (split into two separate apartments) so they could both continue to live with their children -- chronicles the unconventional arrangements of upstairs-downstairs next-door neighbours, let's-get-on-with-it divorcers like her.

The book refers to these as "re-arranged marriages," and Ms. Cochran describes her own situation this way: "We share a house. He lives upstairs, I live downstairs, and our young children and dog float between us. It is unorthodox, but we've discovered we're part of a growing number of couples who, for the sake of their children, are creatively reconfiguring their families from the ruins of disintegrating marriages."

In fact, even in those cases where the animosity is most palpable, such as that of Louise, the cheated-on wife blogger, there are still considerable moments of reprieve from what is otherwise the volatile storm of daily life with a soon-to-be ex.

"It's not healthy or happy. But it's not like that all the time. We'd both be dead if it were," she said.

"We have to go to work, make dinner, and take the kids to lessons. We go out for walks, watch movies, and eat at our favourite restaurants.

"On some occasions, we have sex. Yes, really.? Relationships rarely have a clean-cut ending."