Six years ago Envoy Towers, a large, aristocratic apartment building, was a high-rise ghost town on 16th Street NW.

Only 80 tenants lived in the 334-unit building with a proliferation of rats, roaches and leaking ceilings. Yvonne Toms remembers when the long hallway to her sixth-floor apartment was lined with vacant units.

Today the Envoy, at 2400 16th St., has regained its 1920s elegance, and 25 tenants who endured the bad times are now part-owners of the fully occupied building.

The story of the building's renaissance includes rent strikes and tenants joining with a developer to convert the building to condominiums to prevent the displacement of the building's low- and moderate-income families.

"We were sort of a family," said Toms, 31, who moved to the Envoy when she was a student at George Washington University in 1974. She now works as a loan review officer for a Washington bank.

"We all really had one common goal . . . to try to keep low- and moderate-income housing in the city and not have to move to Prince George's County or other parts of the city to find affordable housing.

The building, which features a stunning original Beaux Arts and Italianate design, was declared a District historic landmark in 1981. It has a new $9 million interior. Chandeliers glitter in the restored lobby, also a historic landmark.

The building has a resident manager, a television-based security system and new heating, electrical and mechanical systems.

Each unit has a dishwasher, and some have ornate stone balconies. There are plans for an exercise facility, sun deck and barroom on the top floor.

All but a few of the Envoy's apartments that range from efficiencies to two-bedrooms are occupied, generally by young professionals and students from nearby Howard University and Antioch Law School.

"The building has a pretty healthy mixture of incomes, nationalities, religions, you name it," said David Julian, the resident manager. "It seems to reflect D.C. as a whole."

For years the tenants struggled to make sure that relatively poor families who lived in the building could remain.

In nearby apartment buildings, poor tenants were being pushed out as the buildings were bought by developers and converted to high-priced condominiums and as the wave of gentrification surged from Adams-Morgan east to 16th Street since the late 1970s.

The tenants in the Envoy finally joined with condominium developer David Clark to buy the building in 1979.

Under their agreement, Clark promised to renovate the building and to sell the vacant apartments at competitive prices.

In return he would subsidize the Envoy's lower-income tenants so they could afford to buy their units, and all the longtime tenants would get to buy their units much below the market selling prices.

The agreement marked the first time that tenants had joined with a developer to try to ensure that lower-income tenants could remain in a condominium. Middle-class tenants often made agreements with condominium developers to buy their nits at reduced rates in return for allowing the developers to convert the buildings.

"It was really a pioneering effort to create subsidized housing for low- and moderate-income tenants with the private sector," said Robert Cook, attorney for the joint venture.

The tenant association, which started during the first rent strike at the Envoy in 1972, received a part ownership in the building because of the group's persistent efforts with the U.S. Department of Housing and Urban Development.

HUD had guaranteed the mortgage on a refurbishing of the building in the early 1960s, but a series of owners defaulted on their mortgage payments and the federal government always had to foreclose and repossess the building.

In 1979, when the government put the building up for sale for the fourth time, the tenants wanted to make sure they became the owners.

The tenants' attorney introduced them Clark, who had been a pioneer in the city's condominium market.

HUD gave the tenants and Clark the right to buy the building if they could match the highest bid made by another private developer.

"We had to make the quick transition from rabble-rousers to serious business people," Roebuck said.

The joint venture bought the building.

But the renovation took two years, and sales began as the condominium market, which once boomed, began to sag and then falter because of high interest rates. To stave off foreclosure, Clark arranged to have ownership of the building transferred to a new group of investors.

It again became an apartment building, and plans now call for selling the units as condominiums in about five years.

The units will probably sell for $56,000 for an efficiency, $82,000 for a one-bedroom, and $110,000 for a two-bedroom, Cook said. But the long-time tenants will have the option of buying the units of their choice at prices ranging from $26,500 to $40,000, he said.

Monthly rents for condos at the Envoy now range from $386 to $412 for efficiencies, $500 to $540 for one bedroom and $650 to $750 for two-bedroom units.

But the rents for the 25 tenants who remained in the building during the bad times are much lower. Fourteen pay rents ranging from $245 for an efficiency to $302 for a two-bedroom. The other 11 pay only 30 percent of their income as rent.

"The experience was very beneficial to many of the tenants and to the community," Roebuck said.

"It made us aware of what was possible working through the system by bringing in a lot of experience and persistence. It was not a piece of cake."