Sometimes it seemed as if their exile would never end.

But last Friday, about three years after moving out of the run-down Pasadena apartment building in Adams-Morgan, 24 low-income families celebrated their return -- as the building's owners.

"A black-and-white banner across the portico of the newly renovated 80-year-old building at 2633 Adams Mill Rd. read, "We Are Back Pasadena Members," and balloons announced the festive celebration in a park across the street.

Among many District apartment buildings bought by tenants in recent years, few have received as much financial help from the city and nonprofit groups. And few have been as much of an ordeal for the residents.

Organizers say the project has helped Adams-Morgan retain some of its valued diversity by keeping low-income and Hispanic residents from moving elsewhere. Yet, the high cost of the building's conversion and the $1.8 million in subsidies it received would be tough to repeat, especially in today's tight times.

"The Pasadena would not get funded now," said the Rev. James M. Dickerson, co-director of Manna Inc., a nonprofit housing group.

A more likely future for old buildings such as this stands a few doors away -- the nearly identical Avalon at 2627 Adams Mill. While the Pasadena got a thorough but plain rehabilitation, the Avalon got a luxury overhaul, a marble lobby and a hot tub on the roof. Open since spring, about half the units in the Avalon remain unsold, the developer said.

In the Avalon, a family buying a $155,000, two-bedroom condominium would need a salary of $60,000 a year by mortgage eligibility standards. In the Pasadena, few households make $20,000, and some have income less than $5,000, according to resident leaders.

A decade ago, both buildings were plagued by leaks, rodents and poor security. Craig Bernstein, a partner in H&M Enterprises, which owned them, said their major systems had failed, and the low rents wouldn't cover the costs of full renovation.

Pasadena resident Daysi Fernandez, president of the new owner-cooperative, said she began fighting the original owners in 1978 when a ceiling in her apartment fell on an empty baby crib.

Tenants began a rent strike in 1981 and started negotiations with the landlord, but problems continued.

In 1987, Fernandez won a civil suit over conditions at the two buildings, and a D.C. Superior Court jury ordered the landlord to pay her $295,000. Bernstein declined to comment on the case because H&M is appealing the judgment.

Meanwhile, Adams-Morgan had begun changing. Apartment houses were being renovated -- including one across the street from the Pasadena, which then became too expensive for its low-income residents.

A break for the Pasadena came at the reopening of that apartment house in 1986. When Mayor Marion Barry spoke and predicted that other buildings would be renovated in the same way, Fernandez said, "I screamed, 'No way! You're not going to touch my building!' "

Barry came over afterward, inspected her deteriorating apartment, and promised the city's help -- a pledge that proved valuable when the tenants decided to buy the Pasadena.

The tenants retained an attorney, Richard C. Eisen, who proposed a buyout. Under District law, tenants have the first right to purchase the building, which could not be converted into condominiums without a majority vote.

By mid-1987, Eisen had struck a deal: The Avalon's tenants agreed to leave so that it could be made into condos, and H&M Enterprises agreed to sell the Pasadena to its tenants for $600,000 and even lend them the money to do so.

A nonprofit housing group, called Ministries United to Support Community Life Endeavors offered to help the Pasadena's tenants plan the renovation, and city officials tentatively approved subsidies. The mayor's interest in the project "got it over the hump," Eisen said.

Pulling together the financing would take two more years. The total purchase and renovation costs amounted to $2.4 million.

A consortium of nonprofit housing organizations provided interim financing of more than $400,000. Permanent financing and monthly mortgage subsidies were provided by four federally supported D.C. housing programs administered by three city agencies.

Together, the efforts provided that the owners owe $1.3 million in block grant money and loans, but will never have to repay $1.1 million in other loans, as long as residents meet low-income criteria.

In December 1987, the tenants moved to temporary quarters so the work could begin. The plan was to return to the renovated Pasadena by the following Christmas, but complications and delays, including a city spending freeze, stretched their exile to almost three years.

"I've seen all of these problems in one project or another," Eisen said. "But in 18 years, I've never run into all of them in one project before."

Through it all, Fernandez reassured the other tenants, four-fifths of whom were Hispanic immigrants like herself.

"I said to my neighbors, 'We have to stop running. We've come so far. We have come from countries where fear is a feeling everyone shares,' " said Fernandez, who fled El Salvador after her stepfather disappeared.

Only three households gave up.

Early this year, the rest were finally asked to choose carpet colors and inspect their new kitchens. "After they saw the kitchens, they went home and just started packing up and throwing away," said co-op leader Mary Lowry. "Nobody wanted to bring anything old into the building."

Finally in late September, moving day arrived. It was, said Lowry, "like coming from hell to heaven."

Fernandez said she remembers one cold day when an insurance agent urged her to give up. "He tried to convince me for two hours: 'It'll never happen, Mrs. Fernandez. There's no way, I can guarantee you that.'

I kept saying, 'I'll invite you to the party when we make it.' "

And Friday, she did.