NEW YORK - Before they were married in September, Nicci Young and Richard Wiese first had to split up.

The problem was not romantic, but spatial: Young Wiese, who organizes community development safaris to Africa, and Wiese, a writer and explorer, found that their Upper East Side one-bedroom was not big enough for the two of them after both decided to work from home.

"He kept talking to me about his work, which is very interesting, but it was really taking time out of my workday," Young Wiese said. "And when I was alone there was a sense of loneliness and procrastination."

Wiese, who is writing a how-to book about exploration for teenagers, acknowledged the problem. "Nicci tends to be a lot more intense," he said. "Especially with lighter work, I can be watching a ballgame. If I saw a funny e-mail coming through I'd want to share it. I'd get these glances from her, like, 'I'm working!' "

Young Wiese is one of many of the millions of Americans now working outside traditional workplaces who have found themselves surprised by how difficult home-office life can be. It requires strict self-discipline and an ability to tune out spouses, children and pets. For the more sociable or emotionally needy, it can feel like house arrest, especially if the phone hasn't rung in a while.

By 2006, according to data collected by the Dieringer Research Group, a marketing research company in Brookfield, Wis., more than 28 million Americans were working from home at least part time -- an increase of 10 percent from just the year before, and 40 percent from 2002. The American Home Furnishings Alliance reports that 7 in 10 Americans now have offices or designated workstations in their homes, a 112 percent increase since 2000.

Boundaries blurred

Young Wiese's solution was to rent space in a communal office, an increasingly popular option for those who can afford it. Those who can't afford a separate space, or who find home too convenient or rewarding a workplace base to give up learn to live with the challenges.

One of the hardest adjustments for those working from home is deciding when to take a break, and when to quit for the day. With the computer always beckoning and the commute measured in the time it takes to cross the living room, there's always a reason to go back to work -- or an excuse to avoid it. "It's sort of a guilty feeling -- I should be working," said Kathy McHugh, a headhunter for high-tech companies who has worked out of her Manhattan apartment on and off for several years. "My office is 2 feet away."

For home-office workers who aren't in regular touch with colleagues or clients, a frequent complaint is of isolation. David Behl, a photographer whose studio is connected to his TriBeCa loft, said he enjoys working at home when the jobs are pouring in and the studio is filled with clients and assistants. But at other times, he added, he misses the studio he used to share with two other photographers. "You don't see anybody," he said. "You don't go out for lunch. It's easier to get depressed because there's no one to complain to."

McHugh said business lunches can be a lifeline after a couple of weeks working from home, and that she often finds herself glomming onto her daughter when she gets home from high school. "I'm happy to see somebody who's out in the world," she said.

Isolation is common

These issues have been observed at IBM, where a "mobile work force" strategy has led to 30 percent of employees working full time from home. "We found if you're working from home and do not have an interaction with someone from work, or a client, or a physical meeting, after three days you start to feel isolated," said Dan Pelino, who manages IBM's mobile work force program. Soon after the company introduced the program in 2001, he added, "people have said to me, 'IBM stands for 'I'm By Myself.' "

The company, which employs about 11,000 at its Research Triangle Park campus, has tried to mitigate this problem with "mobility centers," communal spaces that it maintains wherever it has offices, offering desks, phone and Internet lines, and office equipment for the periodic use by home-based workers.

It has also promoted "IBM clubs" to encourage employee bonding. Club members have taken day trips to a zoo, traded cookie recipes and "gone to a race track and learned how to be a NASCAR driver," Pelino reported.

Among adults

For those who can't depend on corporate beneficence, they can rent a desk or office in communal work spaces all over the country. The Regus Group, a Dallas-based company that rents temporary office space around the world and has 17 locations in Manhattan, has been doubling its American business every two years, according to Guillermo Rotman, the company's chief executive for the Americas. In addition to cubicles and individual offices, its spaces all have business lounges with sofas, armchairs, Internet ports, coffee machines and companionship for those seeking it.

One Regus client in New York, David Robertson, said he had been looking forward to working at home from his Lower Manhattan apartment when he took a job in 2006 with a company that licenses images from college sports events. He lasted less than three months.

"There seemed to be a lot of distractions," he said, "whether it was my children, or the refrigerator, or some home improvement project."

His company pays about $1,000 a month for the cubicle he chose over an office with a closing door because it presented more opportunities to socialize. He now wears a suit and tie to work when he wants to, and enjoys the reassuring cadences of the 9-to-5 world, as well as the camaraderie of his new office mates.

"It's not like they're best friends," he said of his fellow business lounge denizens and the Regus staff members who are there to support them. "But they're adults you can have a conversation with."