When Amanda Kerlin was a model, Fashion Week meant more than runways, parties, and potential fame. It meant that her apartment would be clean and quiet.

Ms. Kerlin lived in housing provided by her agencies on and off for six years. During the twice-annual runway shows — the next of which kicks off tomorrow in Bryant Park — her fellow model roommates were too busy running around town to fight or make messes.

During the rest of the year, the mix of outrageous behavior and tight quarters made for a wild ride at home. It also made for some dishy stories. Ms. Kerlin, 22, now an art history student at the City University of New York, has packed her domicile drama — from models drinking Metamucil martinis to 15-year-old girls bringing new men home each night — into her new novel, “Secrets of the Model Dorm” (Atria, $22.95). Co-authored by Phil Oh, the roman à clef is heavily based on her experiences in a small Financial District apartment owned by an undisclosed modeling agency. Mr. Oh, 26, who now runs a fashion Web site, StreetPeeper.com, was a frequent guest.

As one may expect with such fare, the book’s juiciest tales involve sexual escapades and drug use. In one story that Ms. Kerlin says is true, the unabashed promiscuity of an underage rookie from Wyoming forces the roommates to request a night of peace. After the model relocates her romp to the building’s stairwell, the combined efforts of a security camera, a vigilant guard, and an appalled mother lead to her prompt eviction. Like many of the roommates, the girl is never heard from again.

Ms. Kerlin, whose credits include work for Elle magazine, DKNY, and John Galliano, said models’ accommodations don’t always match the glamour of the catwalk. She considers the lavish lofts on shows such as “America’s Next Top Model” and MTV’s “8th & Ocean” fictional — especially those with prime beachfront real estate.

The real-life situation is far less fabulous. When Ms. Kerlin arrived in New York to model at age 16, her agency provided her a 10-foot-by-12-foot bedroom containing three sets of bunk beds and rodents. “Other agencies might be willing to spend a substantial amount for a nice duplex with separate bedrooms and bathrooms,” she said. “It depends if they have faith in their models making the money back.”

The owner of New York Model Management, Heinz Holba, said the nomadic nature of the business makes agency housing essential. There are 77 designers in Mercedes Benz Fashion Week this year, with approximately 30 models in each show. Newcomers “would not be able to get their careers started unless they had the funds to pay for hotels, which is usually out of the question for them. Also, they are not alone in a new or foreign city.”

Elite Model Management offers a four-story townhouse for nine models in Midtown. The small group is supervised by a female scouting agent who lives on the ground level. The agency provides the rest of its girls with furnished apartments and discounted hotel rooms around the city. Ikon Model Management, a boutique agency, has about 25 girls in six apartments throughout New York and New Jersey.

Tenants typically stay for several months in one dorm before either moving to a new job or their own apartment. Some move back to wherever they came from — and witnessing those returns showed Mr. Oh “the darker side” of the industry.

“Most new girls are herded in and out,” he said. “They’re there for the first few days in New York with all these photographers and agents, and yet nothing happens, so there goes their career.”

In a tight race to the top, proximity and jealousy can make a dangerous combination. “You may have a situation where there’s a response to one type of person in the industry, so only one girl in the room is getting jobs,” a booking agent at Ikon, Sandra Ossei, said. “You’ll have a roommate then, watching her head out every day, fuming, ‘What does she have that I don’t?'”

Although some women grow close, Ms. Kerlin said she never felt this chummy with her roommates. She hasn’t maintained contact with them, and moved into a West Village apartment with non-models after quitting the business two years ago.

“I might live with one, maybe two models, but never a group,” she said. “Paying my own rent is a big step toward adulthood. That kind of drama is more fun when you’re a teenager.”